putting a new set of roller rockers on 17 year old daughters 77 vette is supposed to be 383 stroker problem is dont know the info on the cam it is fairly radical what would be a happy medium for valve adjustment(solid lifters) IM GUESSING 30 THOUSANDS FOR INTAKE &EXHAUST what do you think?

 

dono, Ran a comp solid at 20INT 22EXH

I do know that it needs to be a little looser for an aluminum head though..

 

your guess is as good as anybody elses' at this point!..good luck

 

No problem.Just set them at the same lash as the old rockers.

 

Are you sure the motor really has solid lifters?

 

I had the same problem...bought my vette used...it had a solid cam, but could not decipher the casting numbers to identify what to set the lash at. My neighbor ran Chevy stock cars and told me very good advise...set them at .030" intake and exhaust as that's the most Chevy ever did. His reasoning? What's the worst that could happen? Lots of clackety-clacking and not optimum timing if it really needed less lash. But you'll burn the valves if set tight and it really needed .030". I guess I'm just too **** when it comes to unknowns like that and replaced the cam a few weeks later...just for my peace of mind.

 

thanks for info ,ill set them at 30 cold will put them around 26 hot, my 1st time with roller rockers any tips should i use loctite? working with aluminum heads also should i adjust valves at tdc? camshaft has huge lope to it thanks

 

You bettter make darned sure you have solid lifters before you set them up at a 30-30 clearance. Not many builders use solids except for special hi-rpm applications, so the chances that you have a solid roller cam in that car are not high, especially if it's a street car that's mild enough to be driven by a 17-year-old. If it's a hydraulic roller and you set them at 30-30, you stand a good chance of blowing the spring retainers out of the lifter body.
Lars

 

Your 17 year old daughter drives a 77 Corvette with a 383 aluminum headed stroker, a lumpy camshaft and Dad is installing roller rockers.

Does her mother sleep well at night?

 

My guess is a hydraulic cam, if it did have a solid, it would have a noticeable rattle in the valve train..and a 77 Vette was never one to have very much performance...

 

Use your best judgment with the preset, but I'd recommed adjusting them while it's running. I picked up some valve covers from the junkyard and cut a slot down the middle so that I can get access to the rocker nuts, but I was adjusting a motor with hydraulic lifters.

The nice thing about solid lifters is that you can set them cold and get them perfect the first time without the mess of adjusting them while it's running, but of course you would need to know what to set them at, but my point is that you can always fall back to adjusting them while it's running...then once you have all the clatter adjusted out of them you can measure the gap and write it down somewhere.

I do have a question though...why isn't your daughter doing the work? If she's tough enough to drive a corvette then she shouldn't be afraid to get a little oil on her hands.

 

If she's tough enough to drive a corvette then she shouldn't be afraid to get a little oil on her hands.

Back to the solid vs hydraulic cam. If it were my car, I wouldn't go a step further until I knew for sure exactly what cam I had. It's so important to the longevity of the valve system to have parts that are designed to work together and have them assembled (adjusted) correctly.

Just my .02

BTW, my daughter can't wait to drive my '73

 

I disagree - aluminum heads expand more than cast iron and will actually loosen lash as the engine warms up. This is from testing with my AFR 210s on a GM 511 block with a Lunati solid roller. I set all at .013 cold and when it warmed up, rechecked the lash - it had opened to .016 on all.

You really need to know what kind of cam you have and to look up the proper lash (if any) on the manufacturer's website. To arbitrarily set the lash to .030 is to invite trouble.

 

Set the lash as a hydraulic cam per my tech paper on the subject - the cam is likely a hydraulic and not a solid. If it's a solid, the engine won't start after you set it with a 1/2 turn preload on each lifter. If it starts and runs, it's a hydraulic and your lash is then correctly set. If it's a solid and won't start, just re-set the valves to about a .020/.020 as a start and you'll be in the ballpark - no damage done.
Lars

 

thanks again for the info just got shaft roller rockers installed WOW VERY SMOOTH!!! YES they are solid! (wish they werent because this is why i went roller rocker ) MORE INFO heres the story I bought a 77 vette when daughter was 13 yr old ,brought it home and told her i would build it for her she said NO WAY im not driving that ugly car 2yrs later and about 15000invested (total off frame restoration ) 500 hp 383 stroker etc etc (built for me) well long story but she asked me for the car so i gave to her for 16 b -day (she is a cautious driver) 3 months later t boned by pickup car totaled she was not hurt she found this car with 65000 miles motor and trans built 4500 stahl TRIED TO TALK HER OUT OF IT ) but she was bit by the vette bug this car is pushing 525 on dyno sheet it is 9out of 10 she only drives in good weather she drives 4 door beat up lumina most of the time!!!!! now back to engine it did have roller rockers on it before it was sold to her owner replaced them with oem rockers have installed them set them at 26 cold (=30 cold allowing for alumimun heads fired right up is a little noisy ,but will let it run to warm up then adjust to 30 hot just needed reassurance on valve lash settings because i do not know specs thanks again

 

so again i ask what would you guys feel comfortable with on valve lash forgot to mention when i removed them they were all very loose some were wearing to the side of oem rockers ??? no i am not going to take cam out to check for specs!!!

 

i would try 20-20 then check with a vac gauge for steady needle at 2500 rpm......

 

Same thing happened to me when I bought my '69. Solid lifter cam and I had no idea what it was.

Personally, I think .030 is way to loose. It's easier on the cam to be a little tight (as long as the valve isn't staying open) than too loose. I would start with .022 intake and .024 exhaust.

 

got it warmed up ended up setting lash at 25 on all sounds about right minor rattle thanks guys

 

by going 25 you are really going .030 with your heads....that's a lot of lash..jmo..