383 valve clearance

[arcticmopar]

 Anyone able to give an example of just what type of noise or just how loud valves would make if they hit the piston. It's not a knock from the bottom and not a tic either. I didn't check valve to piston clearance because no spare head gaskets. lame huh. I have a 383 that I re ringed and installed a set of RPM heads and a comp cams .488/.491 lift cam with replacement rockers and push rods. The deck was just checked for being level not milled. The pistons are TRW L2315's (no valve reliefs) but sit close to flush maybe .004-.007 down ( didn't get a steady reading from dial ind.) Most people have been saying 383's need a bunch of milling to get the pistons near the deck but this engine never had shims under the rocker shafts or shorter push rods indicating decked block or heads and the same intake fit back on, so I figured it wasn't cut.
 I got the motor back together and running but had to shut it down after about 12 min. due to the electric fans blowing fuses and although the noise I did hear wasn't a  it was a    to tell you the truth I can't even say if the noise is consistent with both banks yet(working on the fans )  Will try and get a pair of scopes to listen with tomorrow, just trying to figure it out is all.
 As usual your incite is priceless and sorry for 

[nivvy]

cP will know more about stock clearance..

Here is some help..

http://www.cuda-challenger.com/cc/index.php?topic=47115.msg481137#new

[Chryco Psycho]

rotate the engine to 6* after TDC & try to depress the intake valve if it will not move it is hitting the piston , if it will move put a dial guage on there & find out how much clearance you have

[arcticmopar]

Thanks Chryco, your da man! I figured you would know a way to figure this out w/o tearing down the motor right away. I have a old .484 purple shaft new in the box, just wanted more lift and a newer grind, I know how you feel about comp cams and RPM heads lol.

[arcticmopar]

 Well its official I'm fubard I set the marks to 6* after TDC and only found #2 cyl had the intake open and it didnt budge. I could only get any of them to just barely move even without a load on them but when I rotated the engine far enough so #1 cyl had the intake open I could no longer move it when I could before(but just) The machine shop I had the heads checked out said although he's never worked on a chrysler V8 before no other stock valvetrain could take the type of pressure the RPM spring had!
 So if a .488 lift cam wont clear I guess the old .484 mopar cam wont either. I have a comp cam EH262H (.462/.470 ) that was sent in error just seems a little small is all. I see Engle #K-54HYD also shows .470 but with less duration/lobe sep for a smooth idle any other ideas? My basic combo is again a 383 auto 2800 stall 3.23 gears, TTi headers,X-pipe,holly street dom intake and 800 eddy carb. We have no track of any kind just wide a wide open highway and I cruise at 2800-3000 rpm.

[71chally416]

Well you probably have a bunch of bent valves so head removal is probably in order.
It is possible to notch pistons with the engine in the car but it's not a job you'll want to tackle.

[arcticmopar]

 Lets see if I get this...if I now have .000 piston/valve clearance with .488 lift and I need .080 (strokers sticky on valve clearance) and notching reliefs that deep is something not for me and the smallest cam is an "R/V" UNIT @ .430 lift then only with .030 shims can it work? sounds like a real powerhouse to me.
 If thats the case my only option to use this shortblock is repairing the old iron 906 heads and a mild cam again!   Any guess on just howmuch someone cut off this block to make these pistons sit @ or close to the deck
 

[71chally416]

The thing to do is tear it down and get the pistons notched if you ever hope to use any kind of cam. Chalk it up to learning to check stuff BEFORE you put engines together. Look on the bright side. You already have the pistons marked for the notch positions. 

[arcticmopar]

 Thanks 71chally, will pull a head off tonight and check for carnage.   If I do notch the pistons will the "clay" method stroker mentioned in the valve clearance thread work with a hyd lifter or do I need to use a solid lifter to check. I might as while try it myself since the "machine shop" up here cant do any different.

[Moparal]

I guess you know you could lower your compression and run a thicker head gasket. Cometics would have a size you need. They can come in any thickness. You can also pull your plugs and undo the valvetrain, shoot air into the cylinders to see if you have bent any valves by listening into the intake and exhaust. Also watch to see if the leak gauge drops or is not holding as it should. But I agree that valve reliefs is a must when build any type of hp engine or any engine with almost a zero deck height and larger lifts with split durations. If your cam center line isn't installed right, the chances of a valve hitting is very likely. Did you degree the cam?

[Chryco Psycho]

less duration on the cam will increase clearance at the same lift bu tyou still need .100 clearance

[firefighter3931]

You should have loads of clearance with that cam....something is not right. Did you degree the cam in ? It sounds like the valve timing is waaaay off ! 

I have a much bigger cam with lots more duration and a tighter lsa and it clears just fine with a zero deck 440 and 84cc E-heads. PV clearance is .079intake/.098 exhaust. 



Ron

[Chryco Psycho]

I agree there should be lots of clearance but with the piston zero deck & no notches it could be touching

[arcticmopar]

 Thanks for all the help guys, CAM: even after buying a mopar degree wheel w/intrustions and a dial ind etc I ended up just lining up the marks on gears. I just couldnt come close to understanding the math or instuctions The machine shop was of no help ( the dont bother to check any!) the only person I found that has degreed anything was a ford and made me even more confused.
 Ron (firefiter3931) you say you have lots of clearance...did your pistons have any valve reliefs?
 Moparal: Ya a thicker gasket might help if ness, just want to keep what comp I do have and will just pull heads to check for damage since it sounds like I need to grind some notches. Still cant seem to understand how these pistons are at zero deck on a 383 without cutting the block or heads? The engine ran for 18yrs with the 906 heads and no shims and stk pushrods and rockers. how do I check the preload on the lifters with this set up?
 My latest plans then are: pull heads (have them checked by shop if and replace valves as ness.)
                                    notch piston by hand (using suspected marks on pistons as a guide)
                                    order: DVD from summit on degreeing cams (hope it helps )
                                             solid lifters to check clearance and for degreeing cam( neverd figured out the "let the lifters bleed down part")
                                             a rocker shaft shim kit just incase.
                                             use h/d pushrod set from mancini #7116 (was using stock replacement from mopar) to match the springs better in the heads.
                                             if still not enough room then the low and slow .462/.470 lift cam, thicker head gasket and just be ready to get out the RICERS way as they blow my doors off

[71chally416]

You can always put nitrous on it.