CVR_Rally

I'll take whatever tips you have. I'm going to tackle the timing.

Would a sudden the kick in the pants (power wise) at 5500 RPM and up also be a indication of timing being off?

Chris

CVR_Rally

The manual is not completely clear to me on a couple things.

1) Is the purpose of the piston dial to know exact TDC?
2) Once I'm at 1.4mm it has you loosen the bolts and again turn the engine to TDC but the previous direction has you going past it. Then there is a not not to counter rotate the engine. Confusing.

thomasmryan

I have not tried it yet.


I am kinda of curious of the various methods to get the 'true' tdc by using a micrometer or notches on the flywheel. It seems to me a degree wheel, makeshift or otherwise, would be the most accurate.

And I still don't visualize that you are working off the timing for number 4 while observing number 1.

30 years ago I did an Audi 90 belt and got it off a notch....it would hardly start or run but it would go hyperspace at 5000 rpm.

CVR_Rally

I like his method of viewing the flywheel. That will be a little tough for one person though but I'm sure I could do it. This is the first video I've see of it and now I get it. Thanks for sharing!

This will give me a change to repaint the valve cover again too.

Chris

Jfrahm

I think getting into the micro-level adjustments of the valve timing is a step way too far at this point and suggest doing the checks I have detailed earlier in the thread. This is not a "intake cam is not optimized" problem.

If somehow the leakdown tests are accurate, why mess around with the valve timing at all?

When I do this, I do make a timing tape. I have made them by hand but you can also make them on a computer and play around with scaling, then print 10 of them and use the best one. I mark the intake and exhaust valve lift points on the timing tape and the lobe centers of the cams. When I set the timing I actually set the lobe center of the intake cam.

For reading the tape I bolt one end of a piece of stiff wire to something handy and set the tip as a second mark to reduce parallax error.

I do not like to determine TDC at TDC due to the very small amount of piston stroke per crank degree at TDC and the "dwell" at the top where the piston reverses and you have all the bearing clearance stackup to contend with also. You have that at other points also, but it is easier to see it at +-20 degrees or whatever.

CVR_Rally

When I put the new chain in I triple checked chain tooth alignment. Everything will be checked again when I pull it apart but I never set the cam timing initially and when the PO had this engine installed who knows what they did or didn't do to it. I never found out what happened to the original engine but I suspect a snapped timing belt.

When I pulled that head off initially a couple years ago there was so much carbon on the valves they had warped and one guide was so lose I pulled it out by hand. Lucking the cylinders did not have a defined ridge or scratches on the surface. I should have had the seats done then obviously.

Anyways though likely the cam timing was never done properly so I'm willing to dive in.

Chris

CVR_Rally

I completed the timing calibration and it did pick up a little bit during the test drive. I also discovered the upper balance shaft off by a tooth (lower was dead on).

Power feels like it is up down till you hit 5500 then it kicks you in the pants. I think I need to look at any intake leaks pre-throttle body post AFM. I should also re-seal the TB.

Chris

jimmerp

How did the numbers for cranking compression look after the timing adjust?