One devil unmasked! Can't proceed with repeatable results unless two degree wheels are employed! Aha! the devil lurks, to pounce on the unwary - - but you caught THIS particular one Yep, refit and check the std wheel - - and you'd be surprised how many are paying attention ESPECIALLY since you've been bitten once and are determined to succeed this time
Struggling, I have to admit. Have had quite a few goes. Its a real pain to strip the entire valve train and dti's just to jump a tooth on one sprocket. Using the second woodruff key on the inlet didnt help. There is also a second woody slot on the exhaust (cam driven end) Decided to fit both adjustable chain pulleys, so everthing was adjustable. Broke one fitting it. Combination of talking to a neighbour while doing it, not taking enough care to ensure it was square pish materials. Then fitted the one remaining one to the exh cam, figuring I would time in the exhaust THEN do the inlet, instead of jumping like a madman between the two. The plan was to skim the inlet pulley to get the alignment bacck. This was going quite well, with the exhaust set at 107 degs, but I ran out of sprocket adjustment for the inlet. Simple enough, you would think to advance the inlet cam one tooth. But life is never as simple as it sounds, as this screwed the exh cam setting, how ive no idea. I need a drink..
Art, not engineering - - This process cannot be rushed - - force or impatience destroys harmony, without which no engine sings Ever watched paint dry? Wait until respect returns Our short term goal remains: set correct intake and exhaust cam timing relative to the crank, then establish the clearance between intake and exhaust valves to the piston, each during their critical phase
After stalling for a few reasons, I have widened the pockets and have a before and after photo, if someone can stick it up for me. It may be worthy of a bit of discussion
does this mean you need some pics hosting ? if so send them to mynik00 at hotmail . com interesting thread this one as im looking at cams myself only i have no idea of my compression ratios, but have done a dry wot compression test which is around 208psi across them all god knows what cams to buy
thanks, jamesa has kindly offered also. May have a couple of spare sets when this one is a goer. At my rate of progress there may be no petrol left tho...
I am not the right man to comment on this, but am interested in an answer if it furthers the knowledge discussion as to what works with turbos. An area that is briefly covered in books but not widely discussed. (I have a vested interest with a turbo rallycar: 34mm restrictor)
After a bit more dicking about with 1/2" travel clocks that move around and struggle to repeatedly target the follower(s) , I have now decided I am not going to time the cams at the full lift point. Kent kindly give me the lift at overlap, so that's what I'm going to use. Its got to be 1000% easier, and providing the grind profile is correct (overlap to full lift crank degrees) it must get the right answer. Either way, Ive wasted too much time on this as it is. Just need to verify if the lift at overlap includes the valve clearance, or not.
Jon, that full inlet valve lift at 108 crank degrees or whatever it was, is actually checkable with the engine built, and even with the cam cover fitted. You can get a DTI on No 1 inlet cam follower through the oil filler cap. Most engines will need a bit of playing around on the valve timing anyway to take into account various specific factors relating to that particular engine. It looks like you have increased the valve pockets sufficiently to a point where you should be clear of any issues arising from the cam overlap and piston / valve contact.
Jon, Might not be an issue but reading through I wasn't sure if you had sourced cam buckets or not. Kent make the Cossie buckets with over long center stems. They machined a set up for me to the length I specified for my latest race engine and then supplied me with over sized lash caps which I machined down to size. Assume you are aware and/or have sorted yourself out as you are timing it up but I just thought I would mention it - first time I've seen this thread, it being 16v and all that .
Agree the inlet are relatively accessable, but the exhausts are a right pain, with the gear Ive got. (old, hand me down stuff). The large nose on the cam means a big degree swing either way to find the -5 thou point either side of full lift. To get repeatability not over shooting or rocking the engine, the crank degree wheel is hidden down the back of the engine stand etc etc . As soon as I'm happy with the timing I'll stuff some play doh in and do some clearance checks. Prob repeat at -5 and +5 cam degrees to see how the clearance varies with cam timing. Once set i'm tempted to drill extra clamp bolts on the internal adjustable chain pulley and it looks a bit bling/flimsy.
Tony, Thanks for that. I knew about cossy ones and sourced one from reyland some time ago with a long stem, to assess. I havent placed an order yet, but want to soon. Three options the reyland (seem reluctant to take my money and dont ring me back), a supplier on ebay (200 quid ish) , kent Vs42's you mentioned. Prob go for reylands or kent depending on price. Thinking about making my own lashcaps, anybody recommend a material spec?. Thinking about (end) milling the 7mm follower end and turning the valve end
Bought the (cossy) buckets and lash caps. Both need machining down to suit. EN40, so I have blunt a few tipped tools. Job 3/4 done now, and if I say so myself, looks spot on. Its taken ages tho.
Good stuff. I was lucky I found an unknown make replaceable carbide tipped tool in one of my lathe goodie tins and it turned them down easy enough. After measuring them all up I started with the biggest and worked down to give me a bit of a second chance if I messed one up, just held my breath on the last one! All went ok though.
At last. Cams installed and shimmed to within 2 thou. Cams timed in +/-2 thou at the overlap point. Hurray. Rocker box on. Sigh of relief. Can't believe how long its taken. Working away doesnt help. Ancillaries next, choose a box, and into the car.. Will redo valve clearances after its run, if needed.
