Lotus Europa Community
Lotus Europa Forums => The Paddock => Topic started by: Richard48Y on Wednesday,November 09, 2022, 10:16:36 PM
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It occurs to me that I may have been posting some of my questions to the wrong sub-forum.
They may be more appropriate here?
1970 S2, 807/TS DD, Auto-X, Hill-Climb build.
An enhanced performance street car/occasional mild competition build.
807 engine with TS head, Weber 40's, headers, and whatever other tricks I may add on a limited budget.
It will be a DD in summer out here in rural Nevada.
No intent to subject it to city traffic unless I go to a weekend car show, and that would never be the Hot August Nights jam-up.
Most discussion at this site seems to be related to Lotus/Ford TC engines.
I see a few Renault powered cars being raced so hopefully I may bounce some of my questions off this sub-forum.
While I am not chasing max HP I am very interested in reliability/long engine life mods.
So far the most interesting I have found mention of are.
1. Undercutting the camshaft so that the followers do not hit the casting when on the cam heel.
2. Reducing excess oil flow to the cam for more oil pressure to the crankshaft.
3. Discussion of valve spring pressures.
4. Cutting a 4mm deep relief around the circumference of the cylinder top for a more positive head-gasket seal.
My own musings have me chasing after Beehive valve springs and cryogenic or TiN treatment of cam followers, camshaft, cylinders, and maybe even the crankshaft.
TiN turns out to be very expensive but Cryo is relatively cheap.
Cannot do much more with the Beehive springs goal until I get the cam back from Delta Cams.
I shipped it to them a couple of days ago so they should have it Friday.
They will contact me with their assessment for repair and grinds they offer.
If Delta are able to provide excellent service we may want to make note of that somewhere.
I was originally going to buy a Cat Cams camshaft but Euro 550 and shipping, plus the language barrier made that infeasible.
I believe that Delta will be half the cost, possible less.
My Wossner forged pistons are 77.8 mm for 1595cc.
I expect to have to shave the tops to bring compression down a little.
I have been corresponding with Salv Sacco a bit and bought the pistons from him.
Salv states that the Max Speeding rods have improved from their early days and are now very good.
More as it occurs, suggestions welcome.
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I was going to add some PDF's regards new metal treatments but the files are too large.
MS2, Metal Ion implantation, Moly DiSulphide.
I can email them to anyone who is interested.
Claims are some pretty amazing results for HP gains and increased component life.
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A bit of information not easily found for TS type heads.
Original thickness/height top to bottom.
Nominal height 93.5mm. (3.681102")
Minimum repair height 93mm. (3.661417")
This can be used to find out if the head has been milled in the past and how much.
Seems milling the head also throws off valve-train geometry.
So head milling is not a good means of raising compression.
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Seems milling the head also throws off valve-train geometry.
It depends.
The valve train between the lifters and valves remains unchanged because they're all contained in the head.
The part that can change is the relationship between the cam (in the block) and the lifters. That's what adjustable cam sprockets are for. ;)
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My minor victory of the day is finding that my head is .0073" thicker than "Nominal". :)
This should mean it has never been cut.
I have a lot of notes and comments scattered around the forum.
Tonight I hope to complete my email to Delta Cams.
I also intend to gather much of this information up and post it here after it is organized.
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What I sent to Delta Cams as reference for my new grind.
This may be what I have now?
The 807-12 and the Euro 17TS-844 engine (cooking versions of ~125HP) used a valve timing of 40/72/72/40.
Valve lift: Inlet - 9.6mm; Ex. 9.5mm
This is off a photocopy from Franco-American Imports in the early 80's, it's was sourced out of the Renault racing manual for 12/15/17. picture below.
7701452043 - R12G
Inlet Valves
opens BTDC 40 deg
closes ABDC 72 deg
Exhaust Valve
opens BBDC 72 deg
closes ATDC 40 deg
There was also a more competition oriented cam that some guys are running on the street.
7700524884 - 1600cc Racing
Inlet Valves
opens BTDC 53 deg
closes ABDC 83 deg
Exhaust Valve
opens BBDC 83 deg
closes ATDC 53 deg
From the UK Renault engine expert, Salv Sacco.
A lobe profile that gives 290 – 296 duration somewhere close to these dimensions – (at cam lobe not at valve)
Total lobe height 0.285 – 0.290” lift
54 degrees from peak - .070” - .075”
If that can be ground at 108 LCA and using a theoretical rocker ratio of 1.52:1 and a valve clearance of .015” you should see something very close to these figures:-
Total valve lift = 0.425” Lift at TDC = 0.099”
Set cam timing to show either an equal lift on both inlet and exhaust at TDC, or with .005” - .010” more on inlet than exhaust.
I find this gives a smooth idle, really strong mid-range with a 7K peak.
Start line RPM I guess would be around 4500RPM
All the above is based on what I have used and it works for me!
Most of the folk I have conversed with feel this one is too much for the street.
http://www.catcams.com/products/camshafts/datasheet.aspx?ENGINE_id=194&CAMSETUP_id=752&Language=english
intake exhaust
camshaft data:
lash ramp: 0.40mm0 .40mm
duration @ 0.1mm: :280° :280°
duration @ 1.0mm : 236° :236°
valve lift : 10.00mm :10.00mm
cam lift : 6.25mm :6.25mm
lobe angle : 110° :110°
timing @ 1.0mm : 8° / 48° :48° / 8°
valve lift @ TDC : 2.15mm :2.15mm
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Sal knows these engines inside and out. I would always go with his recommendations.
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Hi Richard,
I'm now building my second engine of this type, which you also have. I'm wondering that you are talking about small budget, but use forged Wössner pistons with Ø77,8 mm bore. They are high end. It's almost a pity that you want to machine them for lower compression ratio. There is also another set of competition pistons available for that bore. These were used by works-supported Renault Formula Renault Europe teams in the 70s. Renault supplied a tuning kit back in the day, which was called the 160 HP kit (SAE horsepower, but nonetheless). I used to have a set of those to spare (picture attached), but gave them away a week ago, because I want to take it one step further with my engine and go for the Wössner pistons with high compression. I'm aiming for 12:1, but my engine has the 318° cat cams shaft with adjustable chain wheel and double valve springs. So not at all driveable on the road.
I have also had good experience with the 310° cam shaft. This brings a huge torque from 4500 RPM onwoards, but not maximum HP at high revs. The 310° is still not useable on the road.
A bit of information not easily found for TS type heads.
Original thickness/height top to bottom.
Nominal height 93.5mm. (3.681102")
Minimum repair height 93mm. (3.661417")
This can be used to find out if the head has been milled in the past and how much.
Seems milling the head also throws off valve-train geometry.
So head milling is not a good means of raising compression.
Do you know, why the minimum repair height is set to 93 mm? My racing head is already well below that and supplies good power. Of course, the combustion chamber is machined in order to fit the high compression pistons. But if the crimp endge in the cylinder head chamber is adjusted to the piston height, it should be no problem to go below 93 mm or is there a danger of cutting into oil or water channels, when doing more plane milling? I have now four cylinder heads and want to modify a second one to full race spec. Maybe even further than the first one, which was a bit more towards safety with compression ratio of 11,5:1.
I love the cylindre head configuration, which is shown attached. It is very high compression, but for 1800 cc. Looks beautiful. Built by JL Engineering. I will take that as a role model for my build.
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I had a lot of difficulty getting an intelligible response from the French companies regards piston specification. I really never did get a clear answer.
I would have been satisfied with the "160 HP" pistons if I had been able to determine the part number and availability.
The Wossner's I bought from Salv Sacco were still much less expensive than having a custom set made.
I am running them as supplied since I feel the undercut of the dome does not allow removing material from the top.
Since this is to be a "Hot" street driven car I may have to pay for race fuel, or mix in some AV100LL to prevent pinking.
As some on the site have said cutting the head does not alter the components which attach to it but can throw off the geometry of the push-rods/cam timing.
Since you have the adjustable cam wheel you should be able to correct your cam timing.
Cam cores are very difficult to obtain in the US so I have sent mine out to be reworked. One lobe was very porous at the nose.
Once it has been welded I will get it reground.
I am still trying to determine the profile but will probably go with Salv's recommendation.
I am also taking note of the cam-heel side interference issue.
This may not occur with the billet CAT cams.
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Do you know, why the minimum repair height is set to 93 mm? My racing head is already well below that and supplies good power. Of course, the combustion chamber is machined in order to fit the high compression pistons. But if the crimp endge in the cylinder head chamber is adjusted to the piston height, it should be no problem to go below 93 mm or is there a danger of cutting into oil or water channels, when doing more plane milling? I have now four cylinder heads and want to modify a second one to full race spec. Maybe even further than the first one, which was a bit more towards safety with compression ratio of 11,5:1.
Hi Stefan,
The minimum head thickness is set by the factory and is intended as a reference point within a retail Renault service environment. It more relates to customer cars & warranties etc. I expect all manufacturers would have something similar.
Once you go beyond that, understandably, you're on your own as far as the factory is concerned – it's a statement as to the limitation of their liability.
On the other hand, I expect we've all seen some seriously shaved & modified heads. Motor engineers may find this acceptable but with some caveats, conditions and agreement from the customer.
For instance, there's the cam and lifter relationship. Also, it's possible the dizzy base may need to be shimmed as it gets closer to they drive gear. We know that removing material from the combustion chamber comes close to the water jacket - lots of things like this.
I once bought a Renault crossflow F2 engine and the owner said he'd blown it up more times than I'd had hot dinners. I laughed and thought that was a pretty funny anecdote but he wasn't looking to make some sort of warranty claim.
Incidentally, that head measures at 92.8mm.
That JL Engineering head is very pretty.
Interesting . . your Formula Renault Europe pistons are a very similar style to the Renault Sport pistons used in the 1800cc Alpine rally cars (pic below). We often see Gordini style pistons with a different pronounced bulbous hump in the middle.
Do yours also have the "FTV' marking? I'm not familiar with the brand so perhaps it is no more.
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It occurs to me that since the cam followers are inclined in relation to the cam thinning the head moves them a fraction from the original factory geometry.
Probably not enough to be a major issue but does it affect their "Spin"?
Bumpy pistons, yep.
Wossner's.
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I guess what happens is the lifters are effective lowered into the cam well.
Hmmm . . can't see it affecting the spin significantly because the lowering still retains the same axial relationship between lifter and cam lobe – happy to be educated.
One thing that comes to mind is whether the lifters run out of 'upwards' travel when the head is shaved. Probably not difficult to relieve the lower entrance to the lifter bores.
Perhaps other thing might be a need to either shorten the pushrods or look at shorter rocker adjustment screws.
I've never seen comment on either of the above so presumably it's OK, but still worth checking.
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For myself I am happy to find my head is uncut. :)
I do intend to grab a set of the Ti. valve spring keepers that are available unless the cost is just crazy.
Looked into Ti. valves from Ferrea and found they are not interested in small volume sales.
My current intakes are 42mm but the faces are worn to concave.
I may have found a less expensive Ti. valve maker but am still unsure of their use in a street engine.
Discussions of coatings and special valve seats come up regards them, more $$$.
I am still looking at getting my cam Cryo treated, my lifter faces and rocker tips plated with ?
Also still trying to find a set of beehive springs with the lowest working spring pressure. For that I need to know my cam specs and valve weights.
I spoke to one engine builder who tried beehive springs in his TS race engine.
He said they were too stiff so wiped the cam.
That was several years ago and since I know beehive springs are now used in everything from Chevy LS to sport-bikes suitable springs should be available.
My hope is that significant reduction in valve train mass will increase component life.
I am surprised the racers have not already found answers to these questions.
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Do you know, why the minimum repair height is set to 93 mm? My racing head is already well below that and supplies good power. Of course, the combustion chamber is machined in order to fit the high compression pistons. But if the crimp endge in the cylinder head chamber is adjusted to the piston height, it should be no problem to go below 93 mm or is there a danger of cutting into oil or water channels, when doing more plane milling? I have now four cylinder heads and want to modify a second one to full race spec. Maybe even further than the first one, which was a bit more towards safety with compression ratio of 11,5:1.
Hi Stefan,
The minimum head thickness is set by the factory and is intended as a reference point within a retail Renault service environment. It more relates to customer cars & warranties etc. I expect all manufacturers would have something similar.
Once you go beyond that, understandably, you're on your own as far as the factory is concerned – it's a statement as to the limitation of their liability.
On the other hand, I expect we've all seen some seriously shaved & modified heads. Motor engineers may find this acceptable but with some caveats, conditions and agreement from the customer.
For instance, there's the cam and lifter relationship. Also, it's possible the dizzy base may need to be shimmed as it gets closer to they drive gear. We know that removing material from the combustion chamber comes close to the water jacket - lots of things like this.
I once bought a Renault crossflow F2 engine and the owner said he'd blown it up more times than I'd had hot dinners. I laughed and thought that was a pretty funny anecdote but he wasn't looking to make some sort of warranty claim.
Incidentally, that head measures at 92.8mm.
That JL Engineering head is very pretty.
Interesting . . your Formula Renault Europe pistons are a very similar style to the Renault Sport pistons used in the 1800cc Alpine rally cars (pic below). We often see Gordini style pistons with a different pronounced bulbous hump in the middle.
Do yours also have the "FTV' marking? I'm not familiar with the brand so perhaps it is no more.
Hi Gavin, the pistons I used to have didn't have any inscription, just the diameter figure, which is 77,8 in my case, and an arrow pointing towards the exhaust side of the piston. The pistons were not forged, but cast, I think.
@Richard, I love the look of the fresh Wössner pistons. Going to purchase them soon, too. I will go for the Ø42/35,35 mm valves. This is the famous Mignotet configuration. Marc Mignotet was the engine guru, who developed and tested the Alpine rallye and racing engines. I heard that this guy had the engine dyno next to his house and fine-tuned all the works Alpine engines there. I was thinking about using bigger valves, but if the guy from Alpines engine department, who slept next to the dyno, found this as the most effective way to make horsepower and torque, I go for it, too.
My dream would be to achieve around 172 HP from the engine, which I read on some occasions should be possible from that engine in a best-case scenario at 7200 or 7500 RPM. The torque figure of 192 Nm (of course a bit lower in the rev range) was also something that I read should be possible, if everything works out perfectly. There's a lot of wishful thinking involved, but as long as I reach 160 HP, I'll be happy.
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What I know about beehive springs could be scratched on the back of an aspirin with a crowbar – or even conventional springs for that matter.
And I thought they were supposed to allow lower seat pressure?
Still interesting and I reckon you're right in that there should be something suitable around – same for Ti retainers. Worth pursuing methinks.
Around these parts, most folk default to using the set up recommended by Collier's in Sydney. Collier's were part of the Oz R12G rally effort back in the day. The R12G springs were prone to breaking so they developed longer springs which meant machining the valve spring seats deeper to accomodate. I put Paul Z on the old Yahoo list onto them and I believe he's happy.
The French vendors now seem to offer 43mm valves instead of the older 42.1mm ones.
Some 'enthusiasts' offer 44mm valves but with offset valve guides.
Some time ago I did a quick experiment with a Nissan 45mm valve (pic below) . . and they're problematic, though the length is OK and could likely be reshaped to a suitable size.
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I expect to have to replace all of my intake valves at the least.
The faces are worn concave pretty badly.
If reground sufficiently I expect they would be sunk into the head.
The matching convex seats will contribute to the problem so I may also have to replace my seats. :(
My hope is that lower beehive spring mass and seat pressure will make a noticeable difference in longevity of the entire valve train.
From Hughes Engines, "When using Beehive springs in place of conventional springs the open pressures can be reduced by at least 10%. This is because the retainer and valve spring (specially the upper coils) are so light, due to their small size, less open pressure is required to control the retainer, springs and valves. The weight loss can be in the neighborhood of 75-100 grams removed from the valve sideof the rocker, which is the most important side. This weight loss is better (and a lot less expensive) than switching to titanium valves. More RPM, faster---beehive springs!
More good news. Spring surge is a big problem in straight-type(non-beehive) springs. The surge is harmonic resonance or vibration in the spring, created when it is rapidly compressed and released, as in a running engine. SpinTron testing has shown that straight springs move around a lot (an unbelievable amount) in a running engine, due to these harmonics. You can actually see the retainer wiggling around in the breeze, like it was waving goodbye. Sometimes, lock(keepers) float around loose in the retainers. In the surging springs, you can see the coils spread apart and compress together of being compressed or released, indicating the varying spring pressures at max lift or on the seat. Scary stuff. What this tells you is that accurate valve control is a nightmare and an accident waiting to happen. Think about this as you watch the "Cup" cars running at 8800+ RPM for 3 or more hours. Don't you think that their engine builder doesn't have ulcers?
A SpinTron is a machine that looks somewhat like a dyno, but it drives the engine. It is used to test (among other things) valvetrain dynamics and harmonics. With high speed photogragraphy and video, the gyrations of the valvetrain can be recorded for viewing later in terror-filled hours. It is hard to believe!
Well, there is relief available for flat tappet cam and hydraulic roller cam users--beehive springs! The beehive springs have very little, if any, harmonic resonance, due to their varying diameter from top to bottom. The beehive springs have many features that make them a better spring choice. The tapered design does not have the harmonic resonance capability of the straight design, virtually eliminating that problem. The small diameter at the top of the spring allows a very small, lightweight retainer(9 grams vs 36 grams) to be used (see photo). Not only is the retainer lighter, but the single beehive spring will replace a much larger and heavier dual spring assembly.
Depending on application, anywhere from 75-100 grams can be reduced from the valve side of the rocker arm. The weight reduction on the valve side of the rocker arm translates directly into high-RPM valve control with lower spring tension. A win-win deal.
Not only that, but with flat-tappet cams we are looking at reduced cam-and-lifter wear or failure (or maybe more lift, but that's another subject). The lighter open pressure also allows hydraulic cams (especially hydraulic roller type) to rev higher and extend their power band. The wire that is used in beehive springs is not round, like normal spring wire. It is an ovate shape, which distributes the stress over the spring's surface better. The material used in the wire is of a higher, purer quality steel than is found in most straight springs, so you can expect them to cost a little more. Hey, you expected all of these good thing for less? Only the government can "claim" that".
Of course the above is in regard to V8's so the weight/mass reduction will be less but the general principles remain the same.
Looking for the link I had to a company with a good assortment of beehive springs to work from.
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FYI - Willa previously said he was using beehive springs in his Renault wedge head.
http://www.lotuseuropa.org/LotusForum/index.php?topic=1053.msg31419#msg31419
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Too bad he does not state a source for them.
And are they same as used for TS crossflow heads?
Too bad the thread ended abruptly, his oiling mods are interesting.
Rather than roller rockers my plan is to treat the rocker tips with a friction reducing coating.
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Hi Richard,
Just reading through this thread and build and can confirm that I have beehive springs that were sourced from a Nissan SR20 supplied by Kelford cams in NZ, ask for Kiel. My engine runs to 8k although power goes to 7500. This was with a very aggressive cam so I had designed and built two roller rocker sets at 1.7 not 1.5 and we have 140hp at the wheels, about 170-180 at the fly taking drivetrain losses into account, this set up is kinder to the cam and valve train and we can make a cam with a profile that keeps the valve open longer at full lift. I will have the engine on an engine dyno early in the new year as I have had another head being built where we have welded up the chambers then shaped them to get better flow and combustion characteristics. This is likely as far as I can go as this is on a wedge head / 821 engine with lots of supporting mods......unless I get the itch again.. Good luck with your project.
Cheers
Willa.
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Thank you for the clue.
I found several makers of those type springs but also see that the SR20 open pressure is higher than the original springs at around 254 lb.
My hope is to actually reduce spring pressure without losing stability.
After hours of searching I found the set listed below.
These seem to be pretty close to original spec but in Beehive type.
Of course the free length and valve stem sizes are not given.
It also seems a set would do two heads so if anyone else wanted a half set the price is not bad.
Ford/Mazda DURATEC 2.0L/2.3L Single Beehive Valve Spring Kit.
SPRK-TS-DUR-BE2
Beehive Valve Spring Kit
OutSpr.OD: 27.70mm
InnSpr.OD: 23.20mm
InnSpr.ID: 15.20mm
Seat Pressure: 82 @34.50
Open Pressure: 164 @ 10mm
Max Lift: 13.00mm
Coil Bind: 21.80mm
Rate: 10.4
Kit spring: SPR-TS1015-BE
Kit spring qty: 16
Retainer: RET-TS5.5/EX-BE
Retainer qty: 16
Seat Locator: SEAT-DUR1
OutSpr.ID: 19.70mm
Seat Locator qty: 16
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Got ahold of Supertech.
I would have to get custom retainers made.
But they will sell a half set so that helps to off-set the retainer expense.
Not sure if anyone else would be interested in this if I get it worked out?
Still working on a super-slick coating for rocker tips and possibly lifter faces.
Link to search Supertech for spring specs.
https://www.supertechperformance.com/c22435-valve-spring-kits
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Does anybody know if the same springs and retainers would work for an 821-30 engine? Are the original valve spring specs written down somewhere?
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I have this information via Cat-Cams.
I believe these are specs for a stock set of R16/TS springs and retainers.
I do not know if they are the same as a Wedge head, I would not expect them to be.
intake
exhaust
follower
:  O.E.M. :: D21.70 // d<-> // h<->
:  O.E.M. :: D21.70 // d<-> // h<->
valve lash
:  O.E.M. ::
:  O.E.M. ::
valve
:  O.E.M. :: d8.00 // D40.2 // L110.9
:  O.E.M. :: d8.00 // D35.5 // L110.9
valve locks
:  O.E.M. :: KK-8H: d8.0 // 1gr // A14.3
:  O.E.M. :: KK-8H: d8.0 // 1gr // A14.3
upper retainer
:  O.E.M. :: 27.30 // 19.50
:  O.E.M. :: 27.30 // 19.50
lower retainer
:  O.E.M. ::
:  O.E.M. ::
exterior spring
:  O.E.M. :: D35.9 // d4.2 // Lf54.8 // Ls27.0
:  O.E.M. :: D35.9 // d4.2 // Lf54.8 // Ls27.0
interior spring
:  O.E.M. :: D24.9 // d2.6 // Lf46.3 // Ls19.0
:  O.E.M. :: D24.9 // d2.6 // Lf46.3 // Ls19.0
40 KG = 88.1849 Lb. 78Kg. = 171.9606
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Got a reply from Supertech.
Still a little more open spring pressure than the 150-155 I am ideally looking for.
No Ti. keeper included and only twelve to the set so the price is very good.
I am going to try to borrow or buy samples.
Also found out today that my email to Delta Cams with specs never made it.
So I have re-sent it.
Hello,
The spring below is a beehive spring that may work.
SPR-HM1007BE-12
Beehive Valve Springs
Seat Pressure: 70 @ 39.40
Open Pressure: 197 @ 10
Max Lift: 14.00mm
Coil Bind: 22.80mm
InnSpr.ID: 14.50mm
InnSpr.OD: 24.20mm
OutSpr.ID: 18.80mm
Rate: 12.7
Best regards
Willy Tagliavini
Supertech Performance Inc.
285 Digital Dr., Morgan Hill, CA 95037. USA
www.supertechperformance.com
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Got my cam back from Delta Cams.
The cam card is attached below.
Converting inch to millimeter it seems I will have too much valve lift.
As I recall 10mm valve lift is considered the limit for reasonable cam and lifter life?
This is giving me about 11.557mm!
I really need to know the exact stock rocker ratio, I have seen 1.52-1 and 1.55-1.
Both are above the 1.5-1 the cam grinder used to calculate specs.
At 1.55-1 my intake open would be 11.92784mm or nearly .4696".
This is more than my very hot-rod 327 SBC!
I had expected to have a conversation confirming the grind specifications before the work was completed.
That did not happen and it looks like I need to send it back to be tamed a bit, or send it to someone else, maybe Salv.
Having to ship to the UK and back does not seem reasonable.
Delta had also said they would address the cam heel/lifter face drag issue but they did not.
So I am not really happy at this point and will contact them in the morning to see how this is to be resolved.
I had high hopes for them, I have several more cams needing attention.
Those of you who speak cam please feel free to chime in.
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Email sent to supertechperformance.com.
Hopefully I have not missed anything that should be obvious and will not look foolish.
They are in CA so not too far away if it were not winter.
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I am still trying to find a suitable bee-hive spring to update the Renault type 807.20 engine with 17TS head used in my Lotus Europa.
There are actually a fair number of this type engine still around as they also fit the classic Renault Alpine A110 and Gordini 17TS.
I have this as original replacement specifications.
From a French site, so metric.
intake exhaust
follower : O.E.M. :: D21.70 // d<-> // h<-> : O.E.M. :: D21.70 // d<-> // h<->
valve lash : O.E.M. :: : O.E.M. ::
valve : O.E.M. :: d8.00 // D40.2 // L110.9 : O.E.M. :: d8.00 // D35.5 // L110.9
valve locks : O.E.M. :: KK-8H: d8.0 // 1gr // A14.3 : O.E.M. :: KK-8H: d8.0 // 1gr // A14.3
upper retainer : O.E.M. :: 27.30 // 19.50 : O.E.M. :: 27.30 // 19.50
lower retainer : O.E.M. :: : O.E.M. ::
exterior spring : O.E.M. :: D35.9 // d4.2 // Lf54.8 // Ls27.0 : O.E.M. :: D35.9 // d4.2 // Lf54.8 // Ls27.0
interior spring : O.E.M. :: D24.9 // d2.6 // Lf46.3 // Ls19.0 : O.E.M. :: D24.9 // d2.6 // Lf46.3 // Ls19.0
fitted load / length : 40kg @ 39.5mm : 40kg @ 39.5mm
max. load / lift : 78kg @ 11.5mm (88.1849 Lb.) : 78kg @ 11.5mm (171.9606 Lb.)
(The stock specs did display correctly in my email, not sure why not here)
I measured my valve guide at .489" Dia., .655" above the spring seat without shims.
Seat to bottom of the spring retainer with the valve closed was 1.6".
I have a lathe so may make custom spring seats on my own if necessary.
As near as I can tell SPRK-TS-DUR-BE2 may be usable but the published specs are incomplete.
I do not see free or installed height, the inner and out diameters seem oddly stated as there is no inner and outer spring, just one.
If my estimate appears reasonably correct I would like to buy or borrow a single spring and retainer to test fit.
If they do work I will only need eight.
If they do work I am sure other Renault engine builders will also adopt them.
Excess spring pressure is a killer of our valve trains, particularly cams and lifters.
Cast cam cores are no longer available and billet cams are too expensive.
If you have an alternate suggestion based on the specs I have been able to provide please let me know the part number.
These are your specs I do have:
SPRK-TS-DUR-BE2
Beehive Valve Spring Kit
OutSpr.OD: 27.70mm
InnSpr.OD: 23.20mm
InnSpr.ID: 15.20mm
Seat Pressure: 82 @34.50
Open Pressure: 164 @ 10 (MM?)
Max Lift: 13.00mm
Coil Bind: 21.80mm
Rate: 10.4
Kit spring: SPR-TS1015-BE
Kit spring qty: 16
Retainer: RET-TS5.5/EX-BE
Retainer qty: 16
Seat Locator: SEAT-DUR1
OutSpr.ID: 19.70mm
Seat Locator qty: 16
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Got a response from Supertech.
The springs I had thought might work are too short.
They also have trouble dealing with 8mm valve stems.
I can make custom spring seats on my lathe to take up the missing pre-load.
Supertech are suggesting conversion to 6mm valve stems which would also be lighter weight.
Has anyone done a conversion to "Modern" 6mm valves?
If so, what did you start with?
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Searching the web for 42/43 mm and 35.4 mm Ex. with 6 mm stem valves has been fruitless.
Going to have to make some calls on Monday.
I had a little concern over durability but found that even Nascar engine builders are using them.
They run valves very hard, up to 9,000 rpm for five hundred miles at a time.
6 mm are also used for a lot of current "Tuner" engines.
So I guess they are at least as durable as hollow stem valves that have been around for a long time.
Spent my current funds on a new frame head T, so research is all I can really do on the engine at the moment.
I've found that at least one maker of custom valves has a fifty piece minimum and there is no way I can do that unless at least ten more folk want to go this route.
I will be contacting additional possible suppliers in hope of a less expensive solution.
I hope to eventually have an upgrade valve-train setup that can be shared.
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I think Meca sells guides and valves in 7mm.
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Banging my head against their site, even with web translation it is frustrating to search.
In any case it seems I really need 6mm stems to get Beehive springs to work.
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Are they using 6 mm valves in 4-valve or 2-valve "Tuner" engines?
Haven't researched this but in general, I'd expect commonly available 4-valve engines to use smaller head diameters as they obviously need to fit side by side in the combustion chamber.
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I am still researching but it seems they are in both.
I am being told that 6mm stems now offer the greatest variety of possible valves for the 807/TS head.
NASCAR are a roundy-round race series using American V8 engines.
I think the intake valves are 2.02" but they may be larger.
They may also be Titanium if the rules allow.
I just tripped across Mecaparts offering new lifters with DLC face treatment, at "Only" around $500 USD. ::)
But this does encourage me to continue looking into practical lifter face treatments.
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Pretty frustrated with trying to search Mecaparts.
I have sent them a web translated email asking if they have an alternate site in English (Doubtful) or maybe a list of parts suitable for Europa use.
I was never able to find any reduced stem diameter valves there to help with my Beehive spring goal.
They may well have them, I just cannot locate them across the language barrier. :headbanger:
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Apple now has a translation option built in. Before that I used google-translate. Both work well enough for you to figure out what is on offer. I did two or three orders from them when I was building my crossflow, went just fine though I can't rmember quite how I did it. I believe I made up a list of parts and enquired by email. Then I sent them my credit card details. All pretty straight forward.
You can't expect them to make up a list of parts that might work in a Europa. Not when their business, 99% of it, is performance Renaults. We're just lucky they are making so many parts we can use.
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I did specifically ask which of their aluminum oil pans might work.
I tried translating the item terms I was looking for to match terms on their site too.
No luck there either.
I will make another run at it next week after they respond to what I sent last night.
And the dollar is back in the basement again too. :(
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I am still researching but it seems they are in both.
I am being told that 6mm stems now offer the greatest variety of possible valves for the 807/TS head.
NASCAR are a roundy-round race series using American V8 engines.
I think the intake valves are 2.02" but they may be larger.
They may also be Titanium if the rules allow.
I just tripped across Mecaparts offering new lifters with DLC face treatment, at "Only" around $500 USD. ::)
But this does encourage me to continue looking into practical lifter face treatments.
I have a source for DLC coating in California if you need someone to do it.
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Banks has an aluminium oil pan that works well -- though I had to powder coat mine on the inside to stop some porous areas weeping oil.
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Cam, Valves, Beehive Springs, are sending me in circles.
Each vendor wants specs from the others.
This is the cam I got back from the grinder.
Not sure I can use it, .470" lift at the valve?
The cam grinder says it is a Gordini spec.?
Cam grinder does not have any suggestions for Beehive springs, instead he suggest much stiffer springs than stock.
I need to find more of the original specifications as a starting point.
Some I can just measure, others I need references for.
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Got my head back from the rebuild shop, HBR in Las Vegas.
Pics at my main thread, https://www.lotuseuropa.org/LotusForum/index.php?topic=4056.msg67996#msg67996 (https://www.lotuseuropa.org/LotusForum/index.php?topic=4056.msg67996#msg67996)