chris_barry

I'm trying to get hold of a copy of the spec sheets for a set of Toda spec C camshafts (F20C). I purchased a set of new cams and pulleys off a S2KI member and the spec sheets were missing.

If anyone has them could they scan in a copy, or at the very least look up what the high lift lobe centres are specified at pls.

chris_barry

Another question, I need to machine the exhaust rockers on the low lift cam lobes as with the Spec C cams the lobes contact the rocker body. Is is possible to remove the retaining pin on the roller to make machining easier, or is it a matter of protecting the roller with something and carefully machining around it.

I tried to knock the small pin out of a damaged rocker I have and it appears to have been peened on both ends making them too wide to drift out.

kial007

You could check with Tommy or Aaron from GoTuning. Also blacktrax (Black Trax Racing) put a set of these in a couple months ago. They had a thread here and on their website.

chris_barry

I found them posted in two threads. The only problem is the resolution is not high enough to be able to read the numbers.

https://www.s2ki.com/forums/index.ph...ic=403477&st=0

https://www.s2ki.com/forums/index.php?showt...5&#entry1724827

jei_s2k

Chris,
The top link, click, click to zoom and click to zoom again.

Wrap the roller before grinding then clean thoroughlyand re-oil with motor oil before install.

chris_barry

Thanks Blacktrax. Missed the extra click to get the higher res version.

I hoping that I can slide some shim steel sheet alongside the roller to protect it while I'm grinding.

bpaspi

I've compared some cam profiles and put them into a CATIA drawing. Sorry, some Notes are in german. OT means TDC, UT = BDC e.g.
Hope this helps...

jei_s2k

IMO it's worth disassembling the rockers and grinding away from the engine. You will need to do more grinding that what the instructions state. Take into account material growth when at operating temp. Make sure you rotate the engine a few times to inspect clearance. A good way to inspect other than by eye is to mark your cam or rocker (free of oil residue) with dychem or if you dont' have anything a Sharpie will do.

It is wise to inspect the intake side as well even though the instructions does not state it.

very interested in your results!

jei_s2k

bpaspi great use of CATIA! It would be sweet if we had this for all the F series cams. Would be nice to have valve lobe curves as well.

chris_barry

I machined the exhaust rockers last night ( off the engine). Really fiddly work. I found I could use a strip of shim steel to protect the roller. Rather than machine a rectangular area like in the cam sheets I found it much quicker to profile a wave across the whole rocker.

I used a 8mm round cylindrical burr cutter. I started either side of the roller with the shim steel to protect the roller, then blended in across the whole width just ahead of the roller, aiming the swarf away from the roller.

I'll put together some pics of the build.

Its a upgrade of my F24C, adding spec C cams, cam pulleys, 13:1 compression, E85 and ITB's. Should go ok in my 500kg race car.