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Post by sc397 on Jun 14, 2018 8:39:01 GMT -8
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Post by Captain Awesome on Jun 14, 2018 10:10:08 GMT -8
My bud did it to his and his oil starvation went away in the 1/4 mile. That and opened up the returns in the heads. We didn't know of the 6qt deal you posted of back then. We shoulda checked that the same way you did. DUH.... oh well.
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Post by spud on Jun 14, 2018 13:39:02 GMT -8
Oil will fill up the valve covers to the pushrod holes. That’s about as full as it gets. Not like the lifter valley can trap a lot with like 7 big ass holes in there. Two in front that don’t likely ever drain and the five big ones in the valley floor that are like ten times the area of the drain holes in the heads that are about two thirds blocked by head bolts. So I just figure the block has plenty of drain. The heads are the problem. About the only fix for that is external drain tubes to the pan. So basically you got two quarts trapped in the heads when it turns higher rpm no matter how many holes you put in the block. Unless you add drain tubes or something I can’t think of. Easy fix? A 7 quart or more pan. When the heads trap their prerequisite 2 quarts, you should have 5 somewhere else, hopefully covering the pickup. Now if your a real hot Rodder, you already ditch those queer hydraulic lifters for a solid cam poof the excess oil in the valve covers has lessened considerably. Gee spud, why is that? Valvelash you dork. The pushrod now has gaps when the cam is on the base circle that lets some of that oil leak out and doesn’t spray the fuck up into the valve cover. So you see boys and girls, limiting the oil to the top end with solid lifter or bushed bores makes sense. And if your messing around with a hydraulic cam your just messing around.
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Post by 69Rebel on Jun 14, 2018 18:14:19 GMT -8
I put the holes in the block, if for no other reason, so those low spots don't hold shit in them. Like particles from cam break-in, sludge, etc. I'm pretty much a slow loser, so for the performance aspect, I dunno. But when spud's talkin', I'm listenin'.
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Post by sc397 on Jun 14, 2018 18:44:12 GMT -8
Well messing around with a hydraulic cam describes 90% of the engines that I put together so that is what I am focusing on. If there is a downside to putting in the extra drain back system at a best guess I wonder what the downside vs the upside could be. And remember, we are talking engines that should not see over 6K spurts. We are not talking road racing stuff or exteneded high rpm bonzi runs. My poor mans mentality thinks that you want the oil back in the pan asap. And if you can add a extra drop of oil to the cam lobe every now and then it might be a good thing. Yea the old road racers technology says install a couple of drain back hoses from the rocker arm covers to the pan. The drain back idea through the valley pan area makes sense to me but if I am wrong, I am wrong. I just don't see the downside. I don't see the "keeping the oil off of the rotating assembly" on a relatevly low rpm assembly being detrimental.
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Post by 69Rebel on Jun 14, 2018 18:59:17 GMT -8
When you're at the point where oil on the rotating assembly is a concern, a crank wiper is typically part of the package, isn't it?
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Post by airdrieamx on Jun 14, 2018 21:10:34 GMT -8
I have never tried the extra drainback holes myself but have a 7 qt pan and have never had an issue with losing oil pressure, I definately don't think it would hurt doing it though. One question for you guys, on this next build I'm going to a solid cam and am planning to limit oil up top with an oriface to the lifter galley. What size would you recommend .060, .080" or larger? I do like the idea of drainback lines in the back of the heads, that is also something I might consider doing, would 3/8" lines be enough to be beneficial or 1/2"? It will run up to 7000rpm.
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Post by Captain Awesome on Jun 14, 2018 22:32:39 GMT -8
As far as helping lube the cam, my bud drove his car daily, raced it 2-3 times a week. Drove 650 miles one way to race it. Drove to 125 miles one way to race once a week a whole summer. Drove 250 miles once a Month one way to race. Never ate a cam. prolly had 90,000 miles on a 270 Comp. Maybe the holes helped.
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Post by spud on Jun 15, 2018 8:31:32 GMT -8
I don’t think those holes hurt nothin. I just don’t think they help the problem much. That’s what I think, not what I know through actual detailed research. Now I know for real about the top end filling the valve covers with oil, I’ve played around with that , and amc has a pretty profound tendency to do that. A Chevy will too, but they drain better. As far as putting restrictors in the lifter galley, I can’t visualize how that’s gonna work in an amc, since the passenger side lifter valley feeds the mains. And boring for bushed lifter bores will shrink down the oil passage ( lifter galley) considerably too, but that is one way to limit oil to the top end. Actually, there are solid lifters that have built in limiters to restrict oil flow to the top end. Keeping oil out of the valve covers works much better than trying to get it out through additional drains. And I agree, if your running a hydraulic cam in an engine that might make a few isolated throttle stomps, your probably ok.
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Post by airdrieamx on Jun 17, 2018 19:40:28 GMT -8
Yea I should have mentioned restricting the drivers side only lifter galley not both, I guess there's restricted pushrods to help the situation too.
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Post by 69Rebel on Jun 17, 2018 20:33:34 GMT -8
I've never built a motor serious enough myself, but yeah, the driver's side oil galley can be severely restricted, which is something done on other makes as well. Pushrods with smaller holes, and whatnot. OTOH, I don't know if Jim even did that on his dirt track motor. Maybe he'll chime in.
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Post by airdrieamx on Jun 18, 2018 18:27:05 GMT -8
Me either, this is the first solid cam build i've done so I thought I'd get some opinions. Its taken a few years gathering parts but I've got it all but the balancer and flywheel, kids and family stuff killed the budget for a couple years but its back on track now.
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Post by hurst390 on Jun 19, 2018 13:34:29 GMT -8
On my stock car engine I don't restrict the drivers side because I drilled the block to oil from both lifter gallies..2-5 anyway, you cant drill #1 main. I normally would restrict the drivers side with solid lifters though when oiling with just the right side. As far as the drainback holes I did that for a long time but decided not to anymore just 2 at the rear and maybe 1 extra in front. I think it puts a lot of oil on the crank but I don't believe it to be detrimental. On the next freshen up of the dirt engine I considered blocking the rear drain holes in heads and running it all through my external lines directly to the pan. I can do that on the front of the right side head too but not on the drivers side because I don't have a return line on the left due to power steering. I also run restricted pushrods. I had to put them in the Gremlin engine too because it has morel lifters and they pump a ton of oil. The old crane roller lifters didn't allow much at all in the head. I cant comment on a comp roller lifter I've never used them. The dirt engine runs old flat tappet crower lifters I bought 25 years ago.
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Post by airdrieamx on Jun 19, 2018 18:51:37 GMT -8
If you don't mind me picking your brain, when you restrict the drivers side what size oriface did you drill? I'm using Howards solid flat tappet lifters with the EDM hole. Do you have a recomendation for restricted pushrods, brand & intermal size? Thanks for the response.
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Post by hurst390 on Jun 20, 2018 2:46:59 GMT -8
I drilled an .062 hole in mine and pushrods I've been using smith bros.
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