Collapsed a LS7 lifter
Collapsed a LS7 lifter Here is the setup rundown
370
forged
g5x3 114 cam
trickflow pushrods
patriot dual springs
twin turbo
ls7 llifters
I measured for pushrod length and everything but we burnt a wire and then pulled the valve spring and guess what a collapsed ls7 lifter. Any suggestions going for 900+ whp
370
forged
g5x3 114 cam
trickflow pushrods
patriot dual springs
twin turbo
ls7 llifters
I measured for pushrod length and everything but we burnt a wire and then pulled the valve spring and guess what a collapsed ls7 lifter. Any suggestions going for 900+ whp
I had a Cadillac lifters break on me, around the roller just cracked and broke off. I know of quite a few people that have had them break. I am currently running the LS7's without issue but I am no where near 900hp lol.
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I haven't had a lifter problem yet and I been in the 850-950 rwhp ballpark for a couple of years with different cams, cubes and power adders. Rev limiter set at 7400 RPM. LS7 lifters. What length did you come up with for the pushrods?
7.3s with the decked block and heads milled. We were making 640 hp on a mustang dyno(750ish dynojet) at 12 psi spinning 6500. Had very few miles on them. Putting morels in. Jermey don't cheap on lifters its not worth risking.
I use this method. I copied this from a post by Shane at Thunder.
Here it is again in a nutshell:
1. Using the EO/IC method, get the lifter to the base circle of the cam.
2. Using a known length pushrod (7.400" is a good start with stock rockers) run the rocker arm bolt down to zero lash. This is easily done with your fingers "wiggling" the rocker, the point at which the "slack" is just gone is zero lash.
3. Set your torque wrench to 22 lb./ft. Tighten the rocker to full torque and count the number of turns it takes to get there. 1 full turn wtih a stock 8mm X 1.25 bolt is ~.047" preload as measured at the pushrod/rocker interface.
4. I normally shoot for 1 1/4 to 1 3/4 turns with stock type lifters like Comp 850's, LS1, LS7 etc.
For an example, if you use a 7.400" pushrod and come up with 3/4 of a turn, you will need at least .025" longer pushrod to get into range. If you end up with 2 1/4 turns, you will need one .025" shorter...
If the OP is running a 7.3 pushrod, then it shouldn't be excessive preload. If anything, that's too short of a PR on stock style lifters. The Morels are taller so they require alittle shorter PR. I run 7.35's in mine with the LS7 lifters. My heads are milled down to about a 61cc chamber (they were originally 65cc) and my block was decked a few thousandths.
Here it is again in a nutshell:
1. Using the EO/IC method, get the lifter to the base circle of the cam.
2. Using a known length pushrod (7.400" is a good start with stock rockers) run the rocker arm bolt down to zero lash. This is easily done with your fingers "wiggling" the rocker, the point at which the "slack" is just gone is zero lash.
3. Set your torque wrench to 22 lb./ft. Tighten the rocker to full torque and count the number of turns it takes to get there. 1 full turn wtih a stock 8mm X 1.25 bolt is ~.047" preload as measured at the pushrod/rocker interface.
4. I normally shoot for 1 1/4 to 1 3/4 turns with stock type lifters like Comp 850's, LS1, LS7 etc.
For an example, if you use a 7.400" pushrod and come up with 3/4 of a turn, you will need at least .025" longer pushrod to get into range. If you end up with 2 1/4 turns, you will need one .025" shorter...
If the OP is running a 7.3 pushrod, then it shouldn't be excessive preload. If anything, that's too short of a PR on stock style lifters. The Morels are taller so they require alittle shorter PR. I run 7.35's in mine with the LS7 lifters. My heads are milled down to about a 61cc chamber (they were originally 65cc) and my block was decked a few thousandths.
I was running the caddy racing lifters and one failed on me and locked the cam and broke the timing chain and ended up bending eight valves. I have Morel lifters in my engine now. I think the LS7 lifter is better than the caddy lifter but I still think I would spend the money on the Morel lifters if I was you.
