12v no Rattle!!!!

the bowl on the non intercooled piston is bigger so I know its still spraying in to the bowl its just doing so at the wrong angle.
 
so for sake of my mind, say when installing the cam during the engine rebuild, the cam was put in a tooth off or something, is there a good way to check the cam vrs crank timing besides pulling the front cover to check the timing marks?? my thoughts are if the cam is off time from the crank it could make it run like it was really advanced or retarded or what not even with the pump timed to the cam.... does that make sence??
 
Yes a cam that is a tooth out will advance or retard valve timing enough to notice.


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Did you verify on the pump tag what pump you actually have. I know or was said a 175 pump. But off the actual pump tag. To know for sure.


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Good way to for sure check tdc is through #1 injector hole with a dial indicator. Just be sure to be carefull and have the piston close to tdc before putting the indicator in. Record before and after piston height measurements (like .050 btdc, and atdc) marking each on the damper then splitting the two recordings will be exact tdc
 
For sure. That's splitting piston dwell. Approach TDC forward and when the dial stops mark the damper. Go past TDC. Do the same in reverse rotation. When the dial stops. Mark the damper.

The difference in marks is the amount of degrees built into the crank that the piston dwells at TDC. The middle of the marks is true TDC. In terms of crank rotation. But from mark to mark the piston remains stationary at maximum travel height. Which is called, piston dwell.




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cam and crank are factory, I pulled timing gear cover to double check cam to crank gear timing marks and all was good, head is coming off sunday to go to machine shop to get a valve job, seems to be a compression problem and its not going past the rings so the head is the next place to look. plus its a good reason to take it off and put head studs in haha
 
jmoritz said:
cam and crank are factory, I pulled timing gear cover to double check cam to crank gear timing marks and all was good, head is coming off sunday to go to machine shop to get a valve job, seems to be a compression problem and its not going past the rings so the head is the next place to look. plus its a good reason to take it off and put head studs in haha
Click to expand...

I personally can't imagine going through all that and pulling the head and not doing a leak down first. A compression test would be better than nothing but only tales a small part of the story, a leak down tales it all. Weather it's by the rings or in the valve job, and even which valve.

Good advise, order a good leak down tool now, then go out to the shop and gut an old 12v inj. and weld a .99 cent air hose fitting on the top of it. Do this before you pull it down.

Here is one similar to what I use, same brand even. Any local race shop or exp. a dirt track shop will have in stock. Good luck

http://www.ebay.com/itm/Engine-Compression-Leak-Down-Tester-Motor-Leakdown-73010-Longacre-Racing-/201022699832?hash=item2ecde2f938&item=201022699832&pt=Motors_Automotive_Tools&vxp=mtr
 
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well the head wasn't done during the rebuild so it was coming off this fall anyway, so its just going to be a lot sooner now. I know its not coming past the rings because the crank case vent has almost no blowby and oil consumption is a minimal at best so that only leaves one spot to look, so in terms im killing two birds with one stone.
 
If your only problem is the lack of rattle I would check and see if you have a stock or aftermarket harmonic balancer on it. If you have a aftermarket balancer there will be a lot less rattle compared to a stock balancer.
 
its a stock balancer, and it has no low end torque at all, don't shut down real fast rolls over a few times
 
jmoritz said:
well the head wasn't done during the rebuild so it was coming off this fall anyway, so its just going to be a lot sooner now. I know its not coming past the rings because the crank case vent has almost no blowby and oil consumption is a minimal at best so that only leaves one spot to look, so in terms im killing two birds with one stone.
Click to expand...

Oki dokie.

Nothing like real numbers to have and compare to when it goes back together either. But I can see if you don't have one and not familur with using one and its worth, then you don't know what your missing.
 
I agree 100%, ive never done a leak down test nor do I own the tool to do it, so honestly I don't know the value of the numbers. I wanted to do the head before so now i figure just do it and go from there.
 
Have you checked your fuel pressure? Make sure it's high. You will want 40-60psi of fuel pressure if you plan to turn much over 3,000rpm.
 
I've checked fuel pressure and it's a new bosch over flow valve. It wasn't that high but never dropped below spec (can't remember the number) even under full throttle at max rpm
 
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