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Should I or Shouldn't I [engine assembly]

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Bruce_B

Bruce_B

Jedi Warrior
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Almost done with putting together my 1275 engine. Only thing left to do is check valve/piston clearance and valve spring binding.

Part of me says to just go ahead and put on the cylinder head and keep going. Other part of me says that after all I've done, don't take shortcuts now.

I just need some encouragement to do the right thing, unless there's an opinion that the tests I mentioned really aren't needed. I've put together other engines without knowing about these tests and they worked fine.
 
I have assembled several B' engines over the years, and never checked either of those items. But then again, I did not install a high lift cam or have the head or blocked shaved. It could not hurt to do the tests, but if things didn't collide before disassembly, I don't see why there would be any issue at this point.

I am not sure what is involved with those tests, but if they will give you piece of mind, and won't take forever, it couldn't hurt to do them.

Hopefully our resident race car guys will have a better answer than mine. /bcforum/images/%%GRAEMLIN_URL%%/smile.gif
 
At this stage, I would definitely clay the piston tops. Coil spring binding should be fairly evident. Even if all together and they do bind, replacing the springs can be done fairly easily without having to pull the head.
 
I would do it, you will loose more sleep skiping this simple proceedure.

Patrick
 
Do it right the first time, you'll sleep better that way!
 
Unless you're using a radical cam with 1.5 lifters and/or shaved the heck out of the head, there should be no problem. With today's octane, I'd bet you didn't really skim the head very much, right? Which cam? 1.5 lifters?

Glen Byrns
 
The Swiftune cam and 2.6 liters, Glenn. The block was shaved "a few milimeters" by the machine shop just to clean it. Head is a new Longman's....ah heck I'll just go do it.....

I need to get remotivated. Thanks everyone.
 
I hope they actually said "a few mils" and meant a few 1000ths. That would be a light skim for flatness. "A few milliimeters" would be a MASSIVE skim job that would change your compression ratio drastically and likely expose the oil gallery cross-drill. 2.6 lifters??????
Stock rocker ratio is 1.3:1, high lift rockers would be 1.5:1

2.6 would put your valves deep into a piston.

Sleep better, use the clay.

Glen
 
I just assemble the head with light springs, and then put a dial indicator on the valve retainer. Starting a few degrees before TDC, I just push the valve down with my finger until it contacts the piston, and record the indicator reading. Continue doing that until a few degrees after TDC, or until the readings start back up. I've never used clay for checking V/P clearances.
To check for coil binding, I set the valves at zero lash, use the indicator to put them at full lift, and measure the coil clearances with a feeler gauge.
Jeff
 
Thanks all...did the clay...all is well. Glen. I sand corrected by "a few mils".
 
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