Freshly Built 383, Oil question

Hey guys, Ive just finished and installed a freshly built 383 engine into my 78 camaro. When I started it up it was incredibly tappety and still is, Im curious how much adjustment of the roller rockers I can do. Now engine has been built for gas. First quick description engine
Pro topline heads 64cc 200cc runners
Holley Contender single plane manifold "for gas"
Msd HEI dizzy swung for lpg
Scat crank
400 harmonic and flexplate
I beam scat rods 5.7"
Dished 8cc Hyper pistons with valve reliefs short skirts
Machined 4 bolt block decked to pop pistons out 27"
Comp cams Hydraulic camshaft 212-12-2 480 lift intake/exhaust 280 deg rotation
Performance lifters
Mellings High volume oil pump with welded on pickup tube
Yella terra roller rockers pedestal mounted

Now when it was really tappety I popped the valve covers off and the oil flow out the top of each roller rocker was really piss week, it was a weep more than a squirt, the front rockers didnt even have oil for quite some time and high revs finally made them weep. The rears spalttered a bit when revs were up around 2500 but dont know if thats because of rocker movement or pressure. I actually expected a higher oil flow. The second part after the oil was on all rockers it was still very tappety. I adjusted the roller rockers as per instructions, take cylinder to point were non lobe section of camshaft adjust finger tight until nil movement of pushrod wind barrell nut down pedestal shaft further half turn lock up with internal brub screw. Now there pretty noisy, do I simply redajust again, or can you wind them down further until no noise, bit concerned how far to wind them down as pistons pop out of block by 27" and gasket compressed is 39"
Any help would be appreciated
Thanks Steve

I don't know if I'm reading this correctly, but are you saying you have .012" head to piston clearance? If so, tighten the rockers all you want, the tapping won't go away. Need a min. of .035" between the head and piston with gasket compressed.

Did you use the Comp lifters? If so, what part no.? A lot of lifters are the anti-pump up style and unless you got the ,#812-16's, you probably got the anti-pump up style and they are always noisy.

Yep thats right 12" clearance between head and piston, this machine work and combo was recommended by the local hotrod engine rebuilders, I said if thats what you recommend go for it. I simply did the assembling. I measured all the pistons as they came out the bores and they ranged from 8" out to 27" out on a dial indicator, as the machine shop pointed out to me when I questioned this they said thats just small inaccuracies between all the components, even though there new and supposedly the same between crank rods and pistons they can vary. So worst piston is 27" out next is 22,20,18 and so forth. So is what your saying that its not the rockers that are making the noise but the pistons. Surely there not hitting if they did it would be really bad, it sounds like its the rockers. The lifters Im not to sure there silver with like a copper coloured bottom section, there hydraulic, as supplied
Steve

The pistons are going to rock in the bore and slap the heads. No doubt. Could be whats happening now.

If it's the lifters, you most likely got the anti-pump up style.

I'd be very worried about the head to piston clearance....

Yeh after your post I rang another engine specialist and he said what the f@@@@, you need at least 35" clearance, I told him about the small inaccuracies and he said thats fine but the tops should have been machined to suit, so there all the same height. Gonna have to buy thicker gaskets and strip it down again and put them in, not happy, hope I havent already cracked or stuffed something
Steve

i was kind of scratching my head with the oil question . You should be making a mess with oil. What kind of oil pressure are you running? Were oil Restrictors used in the back of the block? I use them for solid cam's, but never for a hydraulic. Even with Restrictors in on a solid roller cam i still make a bit of an oil mess.

ha clearences who needs them? how hot was the oil was motor up to temp?what weight oil are u using? how long after u adjusted was it running u have to give the lifters time to bleed down. just jokeing bout the clearence .035 is prolly min. i always heard .060 but never built a racing motor either

Gonna get a direct reading oil pressure gauge today the car only has an idiot light. Oil is 15w/40 brand new, oil pump is mellings high volume. Never heard of block restrictors for oil what and were would these be. The only thing I know that causes bad oil pressure is excessive clearances, but being new find that hard to believe, gauge should tell all, just a bit surprised that it was weeping out of the top of the roller rockers not spraying, could also be a function of the roller rocker to not to sure about that but. Im gonna have to pull the heads of again and run thicker gaskets but like to know about the oil problem if there is one before I start stripping it back down
Thanks Steve

I was just thinking about the noise. These guys are most likely on the correct path with the piston clearance. I just wanted to add something different. The oil restrictors would be in the back of the block and screw in beside the cam plug. We use them all of the time to keep the majority of the oil in the bottom end where we need it the most. If they were used on a hydraulic lifter they might starve the lifter to the point that they dont pump up and make noise. This might also explain the trickle of oil at the Rockers. I am curious to hear what kind of oil pressure you have. Keep in mind if the restrictors were used that it would not show up on an oil pressure check. I have some ideas if your oil pressure is low. but i will wait to spout off until you know what it is.

Yeh the short motor was built by local drag racing specialists, but I said I wanted it for street use. I still ended up with piston pop ups all over the place of varying sizes. I assume your talking about the three allen screws around the rear cam plug, do you restrict oil flow by using larger screws

no. there are actual restrictors that screw in with a small orfice. some look alot like a standard plug on the outside, but when you remove them they are around 1 1/4 long with an O ring.

Okay cant get really thick head gaskets here locally but can get decompression shims there .8mm which is about 32" throw on m,y standard felpro gaskets 39" and now I have 71" gasket,worst pop up piston is 27" means I have a clearance of 44" not exactly what I was after but hey shit happens gone from a 11.3:1 comp engine down to 10:1. I checked oil pressure with screw in direct gauge next to dizzy and cold it was reading 70psi at a 1000rpm, didnt want to wait for it to warm up just in case I do some more damage
Steve

COLD????:eek: Oh that right its WINTER there We finely got summer here in MI. and glad of it.

Cold here is only 18 degrees C mornings its about 3degrees C

Simso, maybe you should pull that engine and go over everything. .027" out the hole and .008" out the hole is way to much tolerance stacking. I got a cheap built 385 on the stand and just to see, I checked mine. This is a standard deck height, .040" over bore with cheap hyper pistons, cast crank, and 5.7 I-Beam rods. No decking, no line bore, cheap, cheap, cheap. My pistons are .024"-.025" in the hole. I checked them all and the .001" could have been me trying to hurry. I checked the block with a straight edge also and it is pretty straight.

I know if I had .019" difference, I would suspect something isn't right. You should be throwing oil all over with the valve covers off. Cam bearings could be shot. I would check all clearances and if you paid these guys to build the short block, I'd go bring it back to them to fix my piston out the hole issue. If they had to deck the block more than .025", they should have started with another block. I could handle a little bit out the hole, but .027" is excessive in my book. I like Zero decked and .039" head gasket but will settle for .025" in the hole and embossed .015" shim gasket.

BTW, that 3 degrees from freezing gave me shivers and goose bumps. Got to go to bed and snuggle up to the wife.

Yeh I live i perth, which is about 2500kms away from where I bought the block from, these guys had a good rep which is why I bought from them and not local. The 4 bolt block prepped with scat crank rods and mogul hypers rings and bearings and cam bearings cost me 3000 aust, the rest cost me close to another 7000 so it hasnt been a cheap exercise. Really not happy if yours is simply standard and within 1" tolerance, it actually pisses me off. Ive been told the reason the block was decked so much is because high comp pistons dont have a good flame front, so what they do is put dished pistons in and deck the block to bring up the compression, that way you get your high comp but you also get a good flame front. The local engine shop wasnt that surprised about the differences but he was surprised that they didnt machine the tops of the pistons to even it all out. And was even more surprised when I said they commented standard quality gaskets would be fine, as this gave me as little as 12" clearance. I went through some old mechanics books I have and the bare minimum they recommend for piston to head clearance was .035". Goddamn not happy
Steve

It's amazing how these so called 'performance' shops can be such hacks sometimes. I would take that block back to where you got it done, and tell him to get busy. Why should you be throwing your good money away? Im not a fan of ever having the pistons above the deck, for any reason. Thats just asking for trouble. (As you see!) Man, Im sorry to hear of this problem. Nothing much short of a re-do will fix this one. I personally wouldnt worry about the oil seeping out of the pushrods, as long as you're getting oil up there, you dont need it to be spraying out. Im also not a fan of oil restrictors, I think they cause more problems that they help. But that's just my opinion. John

Yeh your roight for experts they really make you wonder, Im not to sure which way to go, firstly Im not going to riip it apart and then ship it back 2500kms just for them to stuff with it again. I dont know whether to use a decompression gasket to accomodate for the piston pop, or whether to remove every piston and machine them to zero deck height, on the worst piston this means removing 27" from its head, then its all gonna have to be rebalanced ect. From what I can work out these pistons are meant to have 25" deck clearance so god only knows how much has been decked, If I go with a decompression gasket it will still keep my compression around 10:1 if I machine the pistons and go back to zero deck height I get about the same. I have my own lathe and mill so if I was to go down the machining path Ill do it myself. Is there any downside that anyone knows about using a decompression shim and standard head gasket. How can I work out how much decking has been done so far
Any info is really appreciated
Thanks Steve

I don't see any reason to mill the pistons and rebalance everything when a change of head gasket could solve the problem. Give it a try and then go from there.

Centerline of the crank to the deck is the deck height. Scat is decent stuff. You should not have that much tolerance stacking. It's up to you what to do, but I would find the problem.

yeh gonna redo everyting measurement wise. One of the guys at work pointed out because there short skirt pistons you get a lot of rock, he asked when I measured the items did I measure them on edges or centres I said edges, so he reckons rock the piston full aft measure rock the psiton full forward and meausre, he believes I may have measured pistons at different rock angles. He can see differences of maybe 5 thou but not 21". Remeasure and go from there
Steve

A new engine should not have that much rocking going on. But still, when measuring you have to measure from the centerline of the pistons long ways with the block. Can you push the pistons around in the bore. Just asking because that much rocking would indicate a sloppy fit

I just went and checked it then the block is still in the car but heads are of, theres no movement that I can tell from pushing around on the pistons, it looks solid, and this is with the psitons at the top of there travel. I mag particle inspceted the heads and there not cracked, theres light marks on the one piston where Id say it made light contact. It does however have on a couple of the top of a couple of the pistons a gunge like a filthy grease that you get under your car. It comes of but its really really sticky, certainly wasn there when I assembled it, im assuming this is carbon build up whilst still wet and fresh. Anyone got a good way of measuring piston height without dial indicator is there a better way, I may be getting some movement when turning the arm on the magnetic base, dont really think so but maybe
Steve

The only other way I can think of would be with a slide ruler(I think that's what it's called) beings they are out the hole.

It's a height and depth gauge.

Attachment 14415

Actually you just made me think, thanks for that I actually have a vernier depth gauge made by starret with a wide foot tucked away forgot all about it. I can place the foot on the piston and mic down to the block. Excellent. Any ideas on the gunge, would this be simply wet carbon, if it was bad oil ring staggering what would I get.
Steve

Sounds like the engine needs to "break in" and seat the rings. I wouldn't worry about that too much. It will cleanup with some driving most likely.

Thanks for the fast reply mate, youve been a saver this time around with plenty of good advice. Didnt even think about the fact that the rings have to bed in. never stripped an engine before after running it for only 10 minutes. Well thanks and Im going to go out and remeasure using the depth gauge I have and start again. The heads wernt cracked and the pistons still appear to be pretty good.
Appreciated
Steve

Thanks for the help guys, its all back together and running sweet, machined down the pistons and even installed decompression shims to bring compression back to 9.6:1. No knocking gee what a surprise, one last question if anyone can help out Im running 10 degrees initial timing and I just drove the car and turned it off came back about 6 minutes later tried to start her and ended up cooking the starter motor, and melted the battery terminals. Is it reluctant to start hot because of the amount of initial timing, it cant be vapour lock because I dont run pump petrol just lpg which works only by a vacuum draw. Rummm youve got the same camsaft as ive got whats your vac readings at idle or a specific rpm. If i bring initial timing back up to say 2 degrees wont I loose performance, went through the camaro manuals and they run between tdc and 10 deg advance. Recommendations
Oil problem was engine honey from assembly took a bloody long time to come through, now got plenty of oil everywhere
Thanks guys