it looks like it's an oil burner also .
Wait till you see what I find....
- Thread starter bschubarg
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I welded a piece of high speed steel to a spare valve, chucked it in a drill and used the head as a jig to cut some eyebrows in the piston. You can measure the depth with a dial indicator to keep the compression the same. I used a LOT of Vaseline to seal around the edges and just wiped it out after cutting.
stixx
Well-Known Member
Wasn't there a picture in another thread showing how your exhaust valves are basically sorta "inside" the combustion chamber?
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Wow, bud. I haven't seen pushrods bent like that in a while. Did that to my 409 Chevy 20+ years ago.
I would drop those heads off at a machine shop and have them rebuilt with new valves and check the guides. Looks like its burning oil in the pictures. If i recall, your roller cam was only .450ish lift. A lot of bent pushrods for a low lift cam.
I would drop those heads off at a machine shop and have them rebuilt with new valves and check the guides. Looks like its burning oil in the pictures. If i recall, your roller cam was only .450ish lift. A lot of bent pushrods for a low lift cam.
I agree...its like a train wreck...I can't help but watch.
nm9stheham
Well-Known Member
Good thought but the witness marks on the pistons from the valves hitting are plain to see in this case.
Dartnut
Don't hate me because i'm beautiful
Agreed 100%.
There was a mechanical interference which is a nice way to say that the valves certainly hit the pistons and bent the push rods. The marks are there to prove this............
O.P.
How many R.P.M.s was the engine turning when this happened?
Just curious, not trying to slam you.
We all can learn from this...........
.02 Pushrod length is wrong.
If the valves are truly undamaged, I can't imagine the valves alone are responsible for that much "customization" of the push rods.
If that's actually the case, what the heck are those valves made out of??!!..
How long are your pushrods? My factory 88 roller cam 318 pushrods are 6-3/4" long.
Hydraulic flat tappet pushrods are 7-1/2" long. Any possibility that you got the wrong length pushrods?
Hydraulic flat tappet pushrods are 7-1/2" long. Any possibility that you got the wrong length pushrods?
nm9stheham
Well-Known Member
And if the heads were milled as much as one post implies, then the pushrods will too long, without even any change in the lifters.
bschubarg
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Pushrods where the proper length... 7.500....It was my stupidity of having the exhaust protrude beyond the head deck. Didn't think of that since the piston is .070 in the hole...Live and learn... BTW, the valves where Manley severe duty and surprisingly they survived. The factory pushrods seemed to have taken the brute of the compromise.
But in the aftermath, I learned that 'clay' can be an important component of clearances.... I believe I have some purple PlayDough laying around somewhere.....
Another set of 302 heads are installed that haven't been basterized… Take two...
But in the aftermath, I learned that 'clay' can be an important component of clearances.... I believe I have some purple PlayDough laying around somewhere.....
Another set of 302 heads are installed that haven't been basterized… Take two...
If it is a factory roller cam motor, 7.50" pushrods are too long. You best check that. you may end up with the same issue.
Never thought playdough would be of any use to anything in my adult life,thats until i started playing with cars,its a good way to check valveclearance.
I cant imagine those valves still being straight that would take a mirracle,check them real good,and as has been adviced double check your pushrodlengths,you can never check things to many times,its so easy to miss something that will seem obvious afterwards.
I agree. I had a piston kiss a couple valves on my old motor...it left light witness marks...the exhaust valve was really bent, but the intake was hard to tell until I did the following.
Easy way to check the valves (with the heads off), remove the springs and spin the valve back ad forth with your fingers while looking at the head of the valve. If the head wobbles even the slightest bit replace the valve. Also, if you feel resistance from the valve stem (with the valve off the seat), replace the valve.
let me repeat that is the wrong pushrod length.
If you are using a seven and a half in length pushrod that is way too long.
You need the push rods from a 1990 360. They are less than 7 in Long.
6-3/4" is what's in my factory 1988 roller cam 318.
I basically made the same mistake you did. On my first 426 Hemi I put in a Crower roller cam with these really neat aluminum roller lifters. Dummy me being the first time not asking anybody how or what to look for I stuck the hydraulic lifter push rods in it and when I tighten down the rocker arms assemblies.
I didn't notice that it shoved all the valves open. I couldn't even crank it over but it bent every pushrod and every valve in the motor. Course they were 11/32 stems on those valves and it was a 13 1/2 to1 motor so it had plenty of Dome on the Pistons.
I've never made the same mistake since. Lesson learned.
nm9stheham
Well-Known Member
I looked back at the prior thread on this.... original cam was a hydraulic flat tappet. OP changed to a custom roller cam. OP, please take note of the above. (Unless you found some roller lifters that are exactly the same length as flat tappets, or there is something really different here that we aren't aware of.)
yellow rose
Overnight Sensation
There is no hydraulic roller I know of that takes the same pushrod length as any flat tapper lifter.
nm9stheham
Well-Known Member
Exaaaactly...
solid lifters, better know what pushrods you need.let alone springs, rocker ratio
deck height, cam specs .advance
thats about it......
deck height, cam specs .advance
thats about it......
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