ShaneLU97

So I am planning out a partial rebuild including heads, intake, cam, lifters, rollers, pushrods, etc. I am moving from solid lifters to hydraulic lifters.

Since the hydraulic lifters will compress, etc do I / can I use the solid lifters I am taking out to:
1) Check for valve to piston clearance?
2) Measure for proper pushrod length? (I have the comp cams push rod tools)

When I do the final install and get everything bolted up, is the process for setting valve lash the same?
Thanks
Shane

bobs77vet

you can use the push rod geometry tool that slips over the rocker stud to determine pushrod length.....basically as it slips over the stud it will hit the pushrod and valve stem at the same time which is good or it will hit either the pushrod or the valve stem first.....just measure the gap on the other side of either and lengthen or shorten the pushrod as necessary.

and i would use the actual new hydraulic lifters to mock it up, they do not get compressed for this


summit part number PRO-66789 or PRO-66790

ShaneLU97

That helps, thank you. Do you just lightly bolt down the cylinder head for this?

So I would use the tool you suggested in conjunction with a the adjustable length checker like this:
http://www.jegs.com/i/Comp+Cams/249/7702-1/10002/-1
Adjust the adjustable length checker until I get it right?
Thanks
SHane

SanDiegoPaul

How accurate is that? Since putting the AFR's on mine, I have had excessive valve noise and I'm wondering about length too.

midyearvette

that particular part is made by manley and they are dead on.....looks like a blue rocker arm and sooo simple to use....

bobs77vet

well the head gasket will compress under torque....i would do it for real with the head torqued down...........some of the adjustable pushrods are adjustable in .050 increments so we are measuring to the hundreths....

and although i would start with a std pushrod there is no reason not to use the adjustable one....the pushrod tool just slips down over the stud so taking it on and off is painless

bobs77vet

while i think about it....just for due diligence have you read all the disclosures on breaking in cams/lifters

ShaneLU97

My first engine rebuild so probably not...

bobs77vet

you need to read these....breaking in the cam properly is the only way to avoid wiped cam lobes....basically lots of assembly lube must be used and the car must start and run over 2500 rpm for the first 10-15 minutes of life.....the lifters must learn to spin on the cam lobe as it is rotating....if the lifters do not spin then the lobe gets wiped. the high initital rpm helps the lifters to spin. and you need ot use an oil with a high zinc phosphorus content......some people also add the engine break in lubricant for additional zinc protection

heres a link

http://www.compcams.com/Technical/In.../COMP4-116.pdf

ShaneLU97

Thanks. I have been reviewing these instructions and have these along with a lot of articles printed and in a folder.

Since you are in Arlington, I could always use a set of extra eyes on the assembly. I have a grand beer selection I use as bribes.

bobs77vet

now you are talking.....we did meet once when i picked up the car cover from you several yrs ago, ( i lived in NJ at the time and was visiting relatives down here ) i think you had just moved into your house. when are you planning to mock it up?

ShaneLU97

Thats right!!

I am planning to start tearing down the peripherals after T-day and then get the usual crew of guys from the corvette club to pull the engine and transmission sometime in Dec. Then I will spend Dec doing some side projects like cleaning the bay, replacing steering bearings, etc. I will also breakdown the top of the engine, etc.

I am thinking the build-up will start after the 1st of the year.

bobs77vet

count me in.....i have been thinking about joining a corvette club in this area which one do you belong to?

ShaneLU97

Will do.

As for the club, it is the Old Dominion Corvette Club. We are mostly a social club with a core group of "wrenches" who help each other out as well with several 4 post and kwiklifts floating around.

We have an informal meeting this Wed in Sterling near my house. The next real event is the Chili Cook Sat Dec 12th. My wife and I are hosting.

The website is www.olddominioncorvette.com

If you want more information, let me know.

bobs77vet

i was looking at my car mags when i got home and CHP (chevy high performance) nov 09 has an article on this using the pushrod checker you have

ShaneLU97

I have that article in my files as well. I want to compare the method described in that article to using the proform tool listed in the threads above. Seems like the best is a combo but I need to re-read both.

jetnoise

I'd use the solid lifter on an intake and exhaust valve to check pushrod length with your CC tool and PTV clearance.Checker springs are worthwhile having/using if they cam with your tools
Hydraulic lifters will compress.

If your new/future springs are a dual spring set up, you should consider removing the inner for the break in process.

The valve lash setting in a solid set up is differant than hydraulic.

jb78L-82

A few comments about this topic:

First the notion that retro roller cams do not need break in is INCORRECT! They absolutely do! When I uograded/rebuilt my OEM L-82 in 2014 with AFR heads and Howards Roller cam, the expert builder well known in my area did the bottom end of the motor, he was VERY clear that I should use Breakin oil for the engine along with a 20-30 minute breakin procedure despite having a roller cam. The risk of cam and bearing failure are MUCH LESS with a roller BUT are not eliminated. In addition, a Vette magazine article a few years back also stated that many roller cam installers mistakenly assume that a roller cam does not need breakin...WRONG! they do. A roller cam can experience particle contamination just like a flat tappet cams that can destroy the bearings as well.

I just finished my 5th driving season with The L-82 355 with AFR heads and Howards Roller cam and remember very well the absolute confusion and contradictory advice given on this pushrod length issue with a retro roller cam. In summary, the advice given for the shortest sweep and centered is the best I have seen and what I did. I did NOT use checker springs with the AFR heads. I did call howards and ask them for a preload figure for their roller lifters since obviously they will pump up once filled with oil in a running engine. I cannot remember exactly the number (I can look it up once home) but do know that AFR heads are about +.100 higher than stock or other heads. I measured the sweep pattern and made sure that the roller tipped rocker was reasonably centered with a pushrod checker, hand cranking the engine. I checked and rechecked multiple times on different intake/exhaust cylinders. I believe I took the best figure for the length and then subtracted the howards lifter preload to achieve the correct length to order. So if I needed 7.2 as the length and the preload was .05 I ordered a 7.15 +.05 preload to achieve 7.2. 5 years in driving and the rocker sweep is still perfect......Howards was very clear that I did NOT need to change to checker springs to find the pushrod length..it is one way to do it only....NOT the only way

427Hotrod

The little plastic tool MIGHT get you sorta kinda close on a dead stock engine with nothing changed. But in that case you'd just bolt together with stock stuff.

But with differences in valve length, position, stud placement etc on aftermarket heads, cam and lifter changes etc....you need to think it through a little closer.

JIM

A8skyhawk