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Lotus Europa Forums => Garage => Topic started by: ralf on Thursday,September 22, 2022, 09:22:56 PM

Title: BigValve style valve cover for TOYOTA 4AGE 16V engine
Post by: ralf on Thursday,September 22, 2022, 09:22:56 PM
I intall a 4AGE engine to my Lotus Europa. To get a classic look I made a new valve cover for this engine.
First I messured the cylinderhead and make a 3D Model and printed this to check the messurement.
Title: Re: BigValve style valve cover for TOYOTA 4AGE 16V engine
Post by: ralf on Thursday,September 22, 2022, 09:28:24 PM
Next I made a 3D model and tried to transfer the BigValve design to the 4AGE dimension. One oft the difficulties was that the 4AGE camshafts are belt driven which regular get a seperate cover for the belt. Because I want to get a similar design like the TC I choose to make the upper beltcover as a part of the valvecover.
Title: Re: BigValve style valve cover for TOYOTA 4AGE 16V engine
Post by: ralf on Thursday,September 22, 2022, 09:32:02 PM
For the sandcasting I need to scale up the model by 1%. Then I split the model in the inner and outer part. The outer part was filled and mounted to an old which can be mounted to the sandfilling mashine in the foundery company.
Title: Re: BigValve style valve cover for TOYOTA 4AGE 16V engine
Post by: ralf on Thursday,September 22, 2022, 09:34:04 PM
The model for the inside was also mounted to a plate. The models were fillered painted to get a better surface.
Title: Re: BigValve style valve cover for TOYOTA 4AGE 16V engine
Post by: ralf on Thursday,September 22, 2022, 09:36:42 PM
The foundery company installed the canals to cast the cover to the plate.
Title: Re: BigValve style valve cover for TOYOTA 4AGE 16V engine
Post by: ralf on Thursday,September 22, 2022, 09:42:25 PM
The foundery fix the plate to their filling mashine, put a frame to the plate and fill the frame with casting sand. The frame with the sand get removed from the plate. I was very lucky to find a foundery which still make sandcasting for privat people. Most of the founderys get bankruped in the late 1990th because of invirement expenses increased. The next days I will extend this post with the casting and mashining.
Title: Re: BigValve style valve cover for TOYOTA 4AGE 16V engine
Post by: lotusfanatic on Thursday,September 22, 2022, 10:10:01 PM
Hello Ralf,

 :Welcome:

That valve cover is superb!  :trophy:

Mark
Title: Re: BigValve style valve cover for TOYOTA 4AGE 16V engine
Post by: TurboFource on Friday,September 23, 2022, 03:31:32 AM
 8) 8)
Title: Re: BigValve style valve cover for TOYOTA 4AGE 16V engine
Post by: Sandyman on Friday,September 23, 2022, 07:01:06 AM
I just love to see the individual talents members bring to this forum. What a unique Europa we could put together if we got together. Ralf "Gut gemacht" thank you for sharing.
Sandy
Title: Re: BigValve style valve cover for TOYOTA 4AGE 16V engine
Post by: ralf on Friday,September 23, 2022, 08:40:20 AM
Thanks,
the upper mold is put in top of the lower mold.
Title: Re: BigValve style valve cover for TOYOTA 4AGE 16V engine
Post by: ralf on Friday,September 23, 2022, 08:41:51 AM
The two workers at the aluminium casting company put smelt aluminium into the mold.
Title: Re: BigValve style valve cover for TOYOTA 4AGE 16V engine
Post by: ralf on Friday,September 23, 2022, 08:43:51 AM
After the aluminium is cooled down they put the mold to a shaker where the sand is removed.
Title: Re: BigValve style valve cover for TOYOTA 4AGE 16V engine
Post by: ralf on Friday,September 23, 2022, 08:47:48 AM
The worker at the company cut the sprue and ballblast the cover
Title: Re: BigValve style valve cover for TOYOTA 4AGE 16V engine
Post by: ralf on Friday,September 23, 2022, 08:52:12 AM
I don't make only one part, because I was scared to destroy some parts at the mashining and to equip the mashine has to be paid even if I make only one sample.
Title: Re: BigValve style valve cover for TOYOTA 4AGE 16V engine
Post by: jbcollier on Friday,September 23, 2022, 08:56:23 AM
Very, very cool.  Well done.

For those of you with expertise in plastic printing.  Would it be possible to print just such a valve cover using high-temp plastics?  Perhaps add steel inserts at the bolt holes.  I know some some valve covers are plastic now but have zero knowledge otherwise.
Title: Re: BigValve style valve cover for TOYOTA 4AGE 16V engine
Post by: ralf on Friday,September 23, 2022, 08:57:30 AM
With my small cheap milling mashine I cut the area where there is a waterplug at the 4AGE cylinderhead.
Title: Re: BigValve style valve cover for TOYOTA 4AGE 16V engine
Post by: ralf on Friday,September 23, 2022, 08:59:56 AM
The hole for the oil filler was cut, first with a circlesaw.
Title: Re: BigValve style valve cover for TOYOTA 4AGE 16V engine
Post by: ralf on Friday,September 23, 2022, 09:01:31 AM
The exact diameter was made with a boring head. Final the axial surface was cut.
Title: Re: BigValve style valve cover for TOYOTA 4AGE 16V engine
Post by: ralf on Friday,September 23, 2022, 09:25:22 PM
The pins which hold the filler cap were made of aluminium. They are screwed in and fixes with LOCTITE.
Title: Re: BigValve style valve cover for TOYOTA 4AGE 16V engine
Post by: ralf on Friday,September 23, 2022, 09:27:01 PM
The cover is made for the filler cap of the Lotus TC
Title: Re: BigValve style valve cover for TOYOTA 4AGE 16V engine
Post by: ralf on Friday,September 23, 2022, 09:32:52 PM
A fiend of mine who has a big milling mashine cut the planar surface of the cover and drilled the 8 bores.
My cover did not use a gasket. I will use silikone.
Next I make a light countersunk to the 8 bores and mesured the gap betwen the head anf the cover.
Title: Re: BigValve style valve cover for TOYOTA 4AGE 16V engine
Post by: ralf on Friday,September 23, 2022, 09:36:06 PM
To reduse the stress in the cover when tighten the 8 nuts holding the cover, I want a clearance between the countersunk of the bores and the struds of 0,05 to 0,1mm.
Title: Re: BigValve style valve cover for TOYOTA 4AGE 16V engine
Post by: ralf on Saturday,September 24, 2022, 10:27:08 AM
The cylinderhead and valvecover need an opening for the O-ring area of this bracket. because I dont have a big milling mashine I used a manual Hunger valveseatcutter. A guide was made to position the cutter in the center of the camshaft.
Title: Re: BigValve style valve cover for TOYOTA 4AGE 16V engine
Post by: ralf on Saturday,September 24, 2022, 10:28:01 AM
With he Hunger I cut the bore in the head and the cover fixed together.
Title: Re: BigValve style valve cover for TOYOTA 4AGE 16V engine
Post by: ralf on Saturday,September 24, 2022, 10:38:00 AM
Maybe the most complicated work was to mashine the radius which will seal the cover to the first bracket for the camshaft. Because I don't want to damage the front of the cover I could not use a milling mashine (I dont have somebody with a CNC Mashine). It was done by positioning a guide to the cover und use a homemade cuttingtool which is driven by a drilling mashine. Finaly I could do it with a clearance between cover and head of 0,05 to 0,1mm, which can easy sealed by silikon.
Title: Re: BigValve style valve cover for TOYOTA 4AGE 16V engine
Post by: ralf on Saturday,September 24, 2022, 10:45:03 AM
Before painting the cover with VHT Wrinkl Plus the cover was cleaned with aceton and some surfaces get masked.
Title: Re: BigValve style valve cover for TOYOTA 4AGE 16V engine
Post by: ralf on Saturday,September 24, 2022, 10:47:09 AM
After spraying the cover it was heated up in a oven at around 90°C.
Title: Re: BigValve style valve cover for TOYOTA 4AGE 16V engine
Post by: ralf on Saturday,September 24, 2022, 10:49:21 AM
Finaly some areas were sanded down to the aluminium to get the TC like design.
Title: Re: BigValve style valve cover for TOYOTA 4AGE 16V engine
Post by: BDA on Saturday,September 24, 2022, 12:47:02 PM
Great stuff, ralf!!! Very neatly done! I'm anxious to hear about the rest of the car!
Title: Re: BigValve style valve cover for TOYOTA 4AGE 16V engine
Post by: GavinT on Sunday,September 25, 2022, 08:42:03 PM
Phew . . what an absolute over the top spectacular undertaking, Ralf.
Very well done.  8)