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It sounds like the installed height was set too low. I would get either 1/4" longer pushrods or better yet an adjustable pushrod to figure out length and a set of adjustable roller tip or full roller rocker arms. Do you know which Crane cam was used?
It sounds like the installed height was set too low. I would get either 1/4" longer pushrods or better yet an adjustable pushrod to figure out length and a set of adjustable roller tip or full roller rocker arms. Do you know which Crane cam was used?
don't know much about motor, PO didn't know cam specs, just that it was a cran cam ( mild ) He is't much help,I think if I was to change the heads all this would go away. brother told me , I can have the heads off his motor, but they are 1974 # 8's. All my parts worked in his motor with his heads, but my parts will not work in my motor with my heads. I don't want to keep spending money, If there is no need too!
I was also going to say don't run your brothers lifters in your block and if you do go back
with the ones that were in it, I hope you marked them where they went. You don't want a flat cam.
Take the #8 heads and get the valves done so it’s all good, buy new gaskets then install and you should e all set.
as trublu442 said make sure you get the lifters back in the same holes. Something is seriously off with the heads on you motor now. Keep us updated
greg
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.
What valve retainers are you using ? They look like the 1970 valve rotators. What valve springs are you using ?
I'm sorry RustBucket but I don't think you're going to get out of this without spending at least a little money. I'm going through something similar; I bought some ported and polished heads for my 455 build. They have everything awesome, new bronze guides, teflon seals, yadda yadda, but I couldn't get the geometry quite right without the rockers binding on the studs (comp cams roller tips). Like you, the only thing that makes sense is that the valve stems were ground down to remove some kind of nastiness. I'm looking at pulling my heads, having them machined with new valves, which will also mean new pushrods (my current pushrods have about 1500 miles on them, practically brand new). Sucks, man.
I'm also looking into lash caps but that will still require new pushrods (more than likely) and 10 degree locks recessed for lash caps. A bandaid fix at best.
Edit: Whatever you (we) do, we have to make sure the pattern on the valve stem is correct or we'll trash the valves and the guides. It doesn't have to be perfect but should be darn close.
Last edited by Macadoo; August 1st, 2019 at 12:53 PM.
I'm sorry RustBucket but I don't think you're going to get out of this without spending at least a little money. I'm going through something similar; I bought some ported and polished heads for my 455 build. They have everything awesome, new bronze guides, teflon seals, yadda yadda, but I couldn't get the geometry quite right without the rockers binding on the studs (comp cams roller tips). Like you, the only thing that makes sense is that the valve stems were ground down to remove some kind of nastiness. I'm looking at pulling my heads, having them machined with new valves, which will also mean new pushrods (my current pushrods have about 1500 miles on them, practically brand new). Sucks, man.
I'm also looking into lash caps but that will still require new pushrods (more than likely) and 10 degree locks recessed for lash caps. A bandaid fix at best.
Edit: Whatever you (we) do, we have to make sure the pattern on the valve stem is correct or we'll trash the valves and the guides. It doesn't have to be perfect but should be darn close.
I'm going to use the heads off my brothers car, he had them rebuild 3 years ago, and was driving the car, he decided to go with a 455, and pulled his motor.
He doesn't have an extra set of 455 heads he's not using, does he?
That sounds like a good plan. Keep in mind that the head gasket you use will have an impact on compression. Those are '74 heads? The thinner the gasket, the better. And I would still check the pattern when you get everything together, just to be sure.
I read thru this thread just for the heck of it and didn't plan to post to it but I may be able to help. When I rebuilt my 71 Olds 350 back in 1995, I thought I needed adjustable push rods which I bought from Mondellos. So I adjusted the pushrods so the pushrod went down in the lifter .0040 as was recommended. I drove the engine for 10 years until a valve spring broke. Then I decided to go with a stock type cam and have hardened valve seats installed and new lifters, valves and springs,etc. I also decided to go with stock non adjustable pushrods. When putting together the engine I again checked to make sure the pushrods went down.0040 in the lifter and guess what? They didn't go down into the lifter at all. They were loose! I'm sure if I had put it back together like that it would have clattered like yours. I ended up reusing the adjustable push rods. (adjusting each one as I went - down .0040) and again the engine has been together and quiet for another 10 years. I don't know why this was, maybe the valves were shorter or maybe the cam circle was smaller? Or maybe the lifters were different? Or was it the thicker head gasket? I don't know but if I were you I would get some adjustable pushrods and put it together as I did. Good luck and keep us posted.
What pistons are in this motor? You will have low compression with #8 heads with anything but flat top pistons. I say go adjustable on the valve train.
I wasn't sure about the '74 heads either. I know when I freshened my small block '71, I used shim gaskets and barely got to 8.3:1 CR and that was with the #7 heads. I like Greg's idea about the adjustable pushrods but that valve tip pattern will still need to be checked.
Think I found my problem. Took my heads to a friend of a friend, ( he eats, sleeps and breath's Olds ) Took one look and said, the valves are not seated, seats are not ground right. no 3 angle valve job. So off to machine shop, for a valve job !
going a different direction on heads. The friend of a friend had a fresh set of #7 heads , that have 2" valves. bought those , and put on motor, everything is tight and right. Put my motor all back together, ready to start it up and break in the cam. But wait, it's Friday the 13th,and it was a full moon last night. not today, not today ! I have not been lucky with this car, not a time to go against superstition.
August 1st, 2019 | 07:23 AM
