Did a search with no answers. Small block chevy with a fresh rebuild. New full rebuild with Howards retro roller cam, pushrods, heads, ect. New distributor and oil pump of course. Only used parts are the block and crank. the machine shop ran it at on the stand for an hour with no issues. So after a few weeks to get it in the car and about two hours drive I started to hear noises. Thinking it was a new fan belt and pulleys I wasn't concerned but became louder and a squeal. Pulled the belt to disable the pump alt. and fan. Noise worse, after pulling the valve covers I found two broken roller rocker pins were coming out of the lifters, pulled and replaced rockers with a better set my builder supplied. I didn't find much oil but some, now the bad noise is still there. I have good oil pressure on the gauge but no oil to the heads on either side. Nothing through any pushrods or lifters. My builder has a good reputation and says will do whatever to make right. I hate the idea of pulling this motor. any ideas? simple fix I hope?
You didn't say which SBC but the early 265s needed a special rear cam bearing and distributor to complete the oil path. Later you need to verify the holes in the cam bearings line up with the oil passages in the block. Also check that the gallery plug covered up by the rear main cap didn't get left out. The oiling system on SBCs are about as bullet proof as you can get.
Check to see if the distributor is at the right depth, and that the oil groove in the distributor is open all the way around. that groove lets oil to the heads. I was in a bind at a rod run and needed to put a new dist. in my f100 (w/sbc) and got no oil to the heads especially the right one. The oil groove on the dist. was cast in not machined (china) so it didn't go all the way around the dist. The fix was to clock the dist. so the partial groove lined up with the oil passage. After I got home, I canned the China dist. for a good GM hei.
There are 3 little block plugs behind the timing cover around the cam. I believe my friend left these out of his sbc after a rebuild once and also could not get oil to the pushrods. This is my bet.
well it depends upon where the op gauge sender is of course. I am far from a sb expert, Im just saying I have definitely seen no op to the pushrods, and the front galley plugs missing was def the problem in this one instance. On the plus side, the timing chain was very well oiled.
I'd say that the rocker arms that spit the needle bearings into the cam journals and spun a cam bearing.
Here's the "ifs" If Did have oil at machine shop If it did run fine for a bit If it did break parts If it does now still have oil pressure Here's the "buts" There's no oil to the rockers now Here's the "thens" Every pushrod all 16 got plugged Edit, the passage in the dizzy hole got plugged. Here's the "or" Something in the ifs is incorrect
Im thinking it might be the front oil galley plug - I used an old dizzy case and fast 1/2 drill this afternoon with same results - good oil pressure at gauge (off top of the block) but no oil through pushrods. I read on another site that if the rear oil plug was left out under the rear main there would be no pressure - either way it looks like I need to pull it. So then for my next worries... If there was no oil up top does that mean the crank and bearings might have had no oil? Also how can I tell if the roller cam or lifters were damaged? Is it pretty noticeable after a short time? I expect a full rebuild but getting a little worried in case my builder just repairs the broken part and not the long term damage. This was to be my long mile trailer hauler and family cruiser.
And thanks for the help guys - lots of options I've been looking at. Yea - I know I shouldn't have to deal with it but was wishing for an easy fix or something simple. Time for the hoist.
No oil causes plenty of noticeable wear quickly. Not always damage but accelerated wear quickly. The oil fighting thru clearances is what creates pressure The passage directly In the dizzy shaft hole feeds the top end lifters. That dizzy shaft has an oil groove and the oil must follow the groove to both sides for the lifters. If you have just a pump drive shaft to turn the pump you can see the oil come out of that passage. Should you do this you'll also have lower pressure. I just thought of something else, if you got a plug any where around the dizzy shaft, you'll have good pressure and no oil to the lifters which feed the rockers. Check that the best you can.
Wrong valve lifters would be the first thing to check. Some engine rockers get lubed through the rocker arm shaft and not the push rod such as Buicks, older Olds and older Fords etc. The builder may have been trying to use up some old stock.
There is a plug that is in the block under the rear main cap. That plug lines up with where the oil pressure sender screws in to the top of the block, if that plug is missing the oil flow will not go in the correct direction. A lot people do not realize it is there, it is a 1/2" cup plug.
This solves my question as to when I prime motors, i get oil pressure but never oil to the rockers till I fire it up with dizzy in it. Did the engine builder bake the block and all that jazz? I always get the blocks back from the machine shop with a bag full of plugs taken out. One probably wasn't installed like said above
Do the little Chevy engines send oil through the cam bearings to the top end like Chryslers do? I guess they inderectly do this thorugh the hollow pushrods. Tom
back to the builder...im thinking clogged up gallies...did he hot tank and clean out all oil passages....thats probably the culprit
You shouldn't be 'priming' your engines without the proper tool, which plugs the center galley so oil can flow to the lifters. Just using an old shaft and a drill motor will never do it. Worse case scenario, use an old distributor with the cam gear removed and a tang welded on the top of the shaft for the drill chuck.
Thanks again guys, I started the removal and will let you know the outcome. I went with rebuilding over crate for a few reasons service being one of them, hopefully it will turn out fine.
Took this from here - http://www.nastyz28.com/forum/showthread.php?t=225031 Good point! I have a fully machined 350/383 block sitting in a corner of the shop right now that I had assembled to a shortblock stage. This is an early 4 bolt block, and the issue is when GM machined it, they chamfered a bunch of the lifter bores too deep. I caught the problem during assembly, noticing there were a couple of retro hyd roller lifters where the oil band would have been exposed at full lift. It will be fine to use for a small base circle cam or flat tappet, but not for the application I had originally machined it for. If the O/P's lucky, he may be able to see some of the lifters by pulling a valve cover. If so, install a proper priming tool and have someone spin the oil pump while he looks into the lifter valley. What you don't want to see is a flood of oil from around the lifter(s). He'll want to rotate the crank to see if this happens to any of the lifters. It is possible that the lifter bore clearance is excessive. It is possible (but unlikely) that the oil band is exposed on the underside. It is unlikely to be a cam bearing problem. The lifter bores are fed from the back, so as long as some form of cam bearing is installed, it will feed the lifter galleries. It is entirely possible for the rear cam bearing to be installed where the machined groove is exposed (cam bearing not deep enough into block) however in this instance, with oil coming out from random rockers, I doubt it's his problem.
If your block is 1955-57, and you use a newer (1958+) camshaft, you will need a grove machined into the rear camshaft journal for it to oil correctly. When your block was cleaned, a good shop that knows SBC's would have knocked out the plug under the rear main cap. I actually tap that and use a threaded allen head plug when I rebuild SBC's. Many a small block has been assembled without that plug and had to be torn down again and re-installed. This would be my first guess, unless you told me it was a 55-57 block, then see above. I would not think that the oil galleries were plugged enough for no oil to get to the top of the motor. Just to many holes to get plugged. As for them running it for a hour, since you said roller cam, they probably didn't run it over 2000 rpm for at least twenty minutes, like you would with a conventional cam, so with assembly lube, I can believe it. SBC needs very little oil on its rocker to work, but it definetly needs some. This is lame, but will throw it out there. Hydraulic or Solid. And how were they adjusted. Just a thought. cb1
Yep it also give a bell housing full of oil or a large puddle on the ground. Chris, We are going to need more info to find your problem or to help you fnd your problem. I suspect the cam bearings are turned wrong if it is late model but if it is early model there are a multitude of problems you could be having. Wrong distributer, or distributer colcked wrong, no reliefe on the last cam journal, or modern cam bearings in the early block are the most common.
What 31Vicky with a Hemi said in post 22 is most likely what is happening. At break in speeds it got oil but at highway speeds too much oil is being lost around the lifters. You could have lost a plug in the front of one of the galleys but that isn't too likely.
I had no oil issue with a rebuilt chev . turns out the rebuild shop used a oil pump drive rod from a nova mtr and it was too short
Its a mid 70's 350 block. The builder asked me to swap roller lifters tonight since the manifold will be off anyway and prime to see if that happens. I'm betting the galley plug came out since there was noise with each rotation. I am curious but either way I'm sending it back to the builder for him to figure out and rebuild... again. I called Howards cams and they can check the cam to see if there was any damage.
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