Hello all, I am preparing to put the heads back into my '85 after having valves replaced and head refreshed. I measured the lash and before investing in some shims, I want to understand the following from the shop manual. It states the clearances for inlet and exhaust, but then seems to contradict itself. Can someone explain what is meant by "Correct clearance between the tappet thimble....." .020" when it also states. Valve clearance between camshafts and valve pads with cold engine should be: - Inlet 08" ÷ 0.10" - Exhaust: 0,014" ÷ 0,016" Valve timing data - Inlet: - Exhaust: The correct clearance between the tappet thimble and the cam for setting the valve timing: - inlet and exhaust 0.020". Thanks!
Your answer is not specific - If I am setting this up as factory, then it should be timed correctly if crank is at TDC and cam marks are aligned with the markings on the cam caps when the belts are installed... correct? My clearances of cam lobe to shim (pads) are within spec. (so my question is - If exhaust and inlet clearances are correct from cam lobe to shim, and my cams and crank are at TDC (according to markings), then what else could need a clearance correction? Your answer is not specific - what am I setting a clearance of .020? (sorry - just trying to understand where this measurement takes place)
It is very specific. Do you have any understanding of timing cams? You seem to have the book. Have you read it? It sounds like no. If you do not understand the factory cam timing instructions this is a job better left to those that do.
Wow. YOU ARE NOT SPECIFIC and obviously are ZERO help and little knowledge. What an ass. Why waste my time. I thought these forums were for asking questions and getting help from people with knowledge. Why did you even respond to a question that you can answer. It also seems funny to me that you judge people without knowing a single thing about them. I READ THE BOOK! Move on to insult other people ******! - Now go report me for hurting your feelings. Ill be sure to block you.
If you consider that an insult it says a great deal about you. You need to read the book and understand it. Aligning marks is not timing cams. The book has good instructions but it needs to be read, not just the captions in bold. I do actually have a little knowledge. I have been doing it for well over 40 years and have attended a great many factory schools. Listening and learning will get you a lot further than being rude. It is not I that has hurt feelings.
No, but if you have a good running engine and all the marks are well aligned at cyl #1 TDC (flywheel at PM1-4 and #1 at end of compression stroke) before disassembly, it wouldn't be a horrible sin to just repeat that condition for reassembly. What you are missing is those valve clearance values are for two different conditions (manually setting the cam timing vs actual engine operation): When using a timing wheel on the crankshaft, the clearances of the #1 (or #5) intake valve and exhaust valve are set to the 0.5mm clearance (using special thickness shims). When the cam lobe just touches the shim or just releases the shim = those are the defined cam timing "events" (opens or closes) and the degree value is read from the timing wheel on the crankshaft. In the old days, the Factory Mechanic would then reposition the crankshaft to PM1-4 and add the mechanical stamps to the cams aligning with the mark on the cam caps -- with the idea that using these marks again for future reassembly (when just changing the belts) would produce the perfect result. Unfortunately, errors happen, and, in later years, F went away from this, and just used those marks for approximate assembly -- i.e., good enough to prevent valve to piston interference, but not good enough to just reuse them for accurate cam timing. After the cams are timed, then all of the value clearances are set to: Valve clearance between camshafts and valve pads with cold engine should be: - Inlet 08" ÷ 0.10" - Exhaust: 0,014" ÷ 0,016" Good Hunting!
Thanks! That makes sense. The shop manual doesnt spell that out. I had to turn to a couple videos (one specifically from Barkaways) Exactly what I was suspecting but just needed confirmation. I dont want to go through this again. Thank you for the clarification!
