Lifter float - NJFBOA - Home of New Jersey's Camaros and Firebirds

LTb1ow · 09-09-2009, 12:25 PM

I think this is possible right? I know I have seen rev kits that supposedly cut down on lifter float so I hope I am not crazy.

I was looking at my old lifters the other day, and noticed a few of the rollers had marks on them, kinda like they had been chattering on the cam lobe. Would loose rockers cause this?

bubba428 · 09-09-2009, 12:31 PM

hmm that's more of an issue when your valve springs are worn or you rev to high. when the resonant frequency of the valve spring is hit it will tend to actually keep moving even when the cam is at base circle. I would invest in a set of LSx style beehive springs. they are variable rate so that's less of an issue and it will help to raise your max RPM.

sweetbmxrider · 09-09-2009, 12:34 PM

as i was saying, seems like a spring issue to me but i am no expert by any means.

LTb1ow · 09-09-2009, 12:39 PM

PAC 1218 bee hive springs (145 lbs seat and 340 lbs open)

I think I am good there.

bubba428 · 09-09-2009, 01:18 PM

nice

LTb1ow · 09-09-2009, 01:20 PM

So any thoughts on loose rockers causing lifter float?

bubba428 · 09-09-2009, 01:22 PM

did you have a tap?

LTb1ow · 09-09-2009, 01:26 PM

Hard to tell, pro mags are noisy.

bubba428 · 09-09-2009, 02:17 PM

ehhhh you check your PS length? that could be your issue

LTb1ow · 09-09-2009, 02:18 PM

They are correct length, verified with checker and have a good pattern on valve stems.

bubba428 · 09-09-2009, 02:38 PM

huh...maybe the rollers wore out??? you got me stumped, ask JS josh, I bet he'll know

Pampered-Z · 09-09-2009, 03:43 PM

If the rockers were too loose (like you had no preload) then yes that could cause damage, but if your rollers are chewed up then you better look at your cam lobes!

Those springs should be more then enough. I've set up a few cars with 306 and GM847 cams and sprinning to about 6600 with no issues at all, no valve float/bounch or compressed lifters.

The rev kits are useful but you can do better with proper springs. You would be better off going with double springs, but based on the lift of the cam ( I don't know what your running ) you may have to get the heads machined to accept proper springs. The Rev kit was really useful in classes when you had to run stock springs or if you couldn't fit proper springs in the heads. Neither of those are real issues with your heads.

LTb1ow · 09-09-2009, 05:12 PM

Yea its just that I have never been good at adjusting rockers, I can get them to where the engine runs, but I am always hesitant to add more pre load to them...

Pampered-Z · 09-10-2009, 08:05 AM

Quote:

Originally Posted by ShowSomePromise

Yea its just that I have never been good at adjusting rockers, I can get them to where the engine runs, but I am always hesitant to add more pre load to them...

Easiest way:

Do each cylinder one at a time. Bump the engine over until you just start to see a valve start to open (rocker moving, lifter coming up etc) Then adjust the other valve for that cyl.

Spin the push rod with your fingers as you turn down the rocker arm nut, as soon as you start to feel tension stop (your now at zero lash), turn the nut another 1/4 turn and lock it down. 1/4 turn is good for almost all LT1s. Rarely will you need to go any more. Only acception would be if you are running Morel or COMP R lifters, those only get an 1/8 after zero lash.

Bump the engine over until the rocker you just adjusted begines to open, the adjust the other vavle for that cylinder.

LTb1ow · 09-10-2009, 11:07 AM

That is how I usually do it, I know "how" to do it... just always second guess myself and never want to put a lot of lash on it...

S.J.SLEEPER · 09-10-2009, 06:14 PM

how much time on lifters, and are they stock/aftermarket? lifter wheel has a hard coating on them that can wear off and show marks like you are stating and also cause cam lobe damage.

LTb1ow · 09-10-2009, 08:01 PM

The old lifters were stock, replaced em with LS7 lifters.

S.J.SLEEPER · 09-10-2009, 09:18 PM

Quote:

Originally Posted by ShowSomePromise

The old lifters were stock, replaced em with LS7 lifters.

you have a pic you can post. i have changed quite a few lifters & cams due to the coating worn and when used for too long after coating worn they dig into the cam lobes.

not real common but not an unseen problem w/ ls1's (seen bout 3 or 4 times when i used to work for dealer)

cam size? stock springs suck & most beehive type aren't that great either. definitly A+ to go with a set of tsp or comp duals

LTb1ow · 09-10-2009, 09:21 PM

No can do on the pics, the lifters are at home.

Cam is stock

I'll leave it at that.

And I have read nothing bad about the PACs...

S.J.SLEEPER · 09-10-2009, 09:44 PM

Quote:

Originally Posted by ShowSomePromise

No can do on the pics, the lifters are at home.

Cam is stock

I'll leave it at that.

And I have read nothing bad about the PACs...

yeah..... so is mine

myself heard nothing bad about the pac's but if you anywhere near the .585-.625" area than the duals good investment. i've broken so called good to .600" beehives, but also pulld car to 7000-7200 so valve float kind of inevitable with bh's @ that rpm.

the coating being bad/worn will kind of look like a smudge spot on roller or a shiny to dull area and will be intermitent as you spin the roller over

LTb1ow · 09-10-2009, 09:46 PM

Ok, if I am home this weekend I will check them out.

And fyi, this is an LT1 car... no crazy lifts here.

S.J.SLEEPER · 09-12-2009, 12:36 AM

Quote:

Originally Posted by ShowSomePromise

Ok, if I am home this weekend I will check them out.

And fyi, this is an LT1 car... no crazy lifts here.

sorry to hear that..

....j/k !!! i actually wish my ls1 would have that deep rumble of exhaust the lt1's have. i miss my 94 z