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I have a 1970 350 olds, in my Cutlass, it was rebuilt 2 years ago. I just finished car, and I'm trying to get motor broke in. here is my problem, I have ran engine for 40 min now, and lifters are ticking like crazy, they will not pump up! I put oil pressure gauge on it, at Idle I'm getting 20 at 1000 rpm's I'm getting 40. The oil in pan is clean ( like new) but the oil coming from line to gauge is dark and dirty. Any ideas what is going on? do I just need to be patient
I pulled valve covers about a hour ago, and set rockers to 35 . with the valves closed , my valve lash is .065! something is very wrong, I just don't know where to go from here. maybe the wrong parts where installed, or the cam didn't break in, and is toast.
I have never seen that type of bridge on the 70's model engines. These are the type I use.
I don't know if there is a difference or not. Are those #6 heads?
There is for sure a problem those rockers are way to loose.
Tru-blue442 they are #6 heads. My brother has a #8 head motor from a 74 cutlass, we pulled the rockers and bridge ( looks like the one you posted pics of ) from it and put in my motor, same thing, no change.
Last edited by Rustbucket2; July 29th, 2019 at 04:54 AM.
Those are the Aftermarket stock replacement rocker arms they work OK. An aftermarket adjustable or longer pushrods will be needed. It might not be a bad idea to totally disassemble the motor, to see what was all done to it. Your oil pressure is very good, which is a good start.
A straight edge across the top of the valve stems will give you a good indication. Measure the spring from where it sits in the pocket to the bottom of spring retainer. They should all be relatively even.
You have non- adjustable valve train, so if seats were installed in the heads its important that new seats are cut to proper depth to give proper stem height and spring tension.
The response I got from po on heads and cam. I know the cam was a Crane unit, relatively mild. The heads have all new hardened seats to run unleaded. W31 spec int. & exh. valves, new. Valve springs, retainers and locks all new but stock spec if I remember right. I did have it running for a bit but the hi-volume oil pump that was in it blew the seal out of the filter. So that’s where I stopped. Not sure what the problem could be.
A straight edge across the top of the valve stems will give you a good indication. Measure the spring from where it sits in the pocket to the bottom of spring retainer. They should all be relatively even.
You have non- adjustable valve train, so if seats were installed in the heads its important that new seats are cut to proper depth to give proper stem height and spring tension.
I hope to start to pull motor apart, sometime next week, to check lifters and cam. In the event I have to change these out ( I'm sure I will ether way) would a Edelbrock 7112 cam be a good choice? motor bored .30 over, I have 9.5 to 1 compression, heads have 2" valves. But I would like to keep the vacuum I have 18.
Last edited by Rustbucket2; July 29th, 2019 at 05:19 PM.
Tru-blue442 they are #6 heads. My brother has a #8 head motor from a 74 cutlass, we pulled the rockers and bridge ( looks like the one you posted pics of ) from it and put in my motor, same thing, no change.
Were the push rods the same length between the two engines?
I would make sure you have Olds lifters, and not Small Block Chevy Lifters. They look the same, and go in the same hole, but the Chevy lifters have the plunger about .050 farther down. Many people have gotten results exactly like yours because of the wrong lifter. Check that before tearing the whole engine open.
I would make sure you have Olds lifters, and not Small Block Chevy Lifters. They look the same, and go in the same hole, but the Chevy lifters have the plunger about .050 farther down. Many people have gotten results exactly like yours because of the wrong lifter. Check that before tearing the whole engine open.
RB,
I just looked up pushrods for a 1970 350 and they show the length being 8.245" That is just shy of 8 1/4" Unless your picture is at a crazy angle it looks like wyours are almost 1/16" short ?? I would start with getting a new correct pushrod and compare to yours. Or at least find a more accurate way to measure them ?
I would not go with Performer cam with 9.5 to 1 unless the quench is tight and you want a steady diet of 93 octane fuel. My 9.6 to 1 350 with the 204/214 cam was no fun on 91, pinging.
You said the engine was rebuilt two years ago but you don't have specifics. My money goes to the valves were mushroomed or chipped and were ground down. That works okay with an adjustable valve train but not with the stock Olds. After you verify you have the correct lifters, maybe pick up a set of Comp Cams roller tip rockers and polylocks (the short ones) and a couple checker springs. Put it together and check your pattern by covering the valve tip with sharpie marker, crank the engine over a couple of times, and make sure the pattern is centered. If it's not, you'll need the proper pushrods to get it where it needs to be. Lots of info on Google about pattern checking.
As was stated, you have good oil pressure and you haven't mentioned any knocking (if you could hear it over the clacking). Pulling the engine is going to be a MAW hole ("might as well"). Maybe, if you have a dial indicator, you could check the pushrod movement for height and consistency. That would verify the cam lobes are okay.
Just some thoughts. Good luck, buddy.
And I second what 307 advises. I have to run 93 and I've been paying $4+ a gallon. It costs me $3 every time I smoke the tires, lol.
I have box of stock rockers, bridges, and pushrods. Clean. I will have to check to makes sure they are not 455 pushrods.. Probably not as all my motors are small blocks.
I have a brand new box of Erson oldsmobile hydraulic lifters
Went to roller cam and not using.
send PM if interested.
I can send pics, but will be out of town this weekend.
will the head gasket thickness , make this happen? I have .039 thick head gaskets.
Anything that moves the head further from the block will change the valve geometry. Thicker gasket = longer pushrod. Sorry, I don't recall the stock head gasket thickness. I know they were pretty thin as they were just shim gaskets. There used to be a dude here on CO that sells them. His name was Smitty I think.
I think the "old style" steel head gaskets were .017"-.018" thick. Sounds like you have good oil pressure, but the dirty oil coming the oil gauge fitting makes me wonder if the oil is getting everywhere its needed.
took top of motor apart, everything has oil, lifters are pumped up, rockers are soaked in oil, push rods had oil coming out of everyone. push rods are 8.25 long, One push rod has a number RP3174. nothing looks wrong, anyone see anything that looks out of place? I see on push rods are a mark, some where up, some down, does this matter, I know it has nothing to do with my problem. lifters look like right ones, 2" long. Cam looks ok ( what I can see of it )
Last edited by Rustbucket2; August 1st, 2019 at 04:40 AM.
RB,
I just looked up pushrods for a 1970 350 and they show the length being 8.245" That is just shy of 8 1/4" Unless your picture is at a crazy angle it looks like wyours are almost 1/16" short ?? I would start with getting a new correct pushrod and compare to yours. Or at least find a more accurate way to measure them ?
Part # RP 3174 is 8.234 and you say should be 8.245 would ..011 make that much of a difference?
Today, I took my brothers 350 apart, took his parts out ( lifters, pushrods, rocker arms ) and put in my motor, same thing, everything lose. I took my parts from my motor and put into his, they worked great. so I measured my springs ,and this is what I found, 1 3/4 on my motor, 2 " in my brothers motor.
That does not mean anything. Chevy lifters are also 2" tall. Do you have an actual Olds lifter you can compare to ? If so look at my picture below. It is a total exaggeration but shows you what you actually need to measure which is the height of the pushrod seat in the lifter.
It would seem to me that both motors should be the same height on those springs. The only thing that would make any sense is somebody installed shorter valves and springs. Oldsmobile non adjustable valve trains can get tricky if you start changing things. And I think that is the case here. Everything else seems to look good. Keeping an eye on this post to see what the hell is happened .good luck
greg
July 28th, 2019, 02:50 PM
