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#1 |
Registered User
![]() Join Date: Apr 2014
Location: Oakland, Ca.
Posts: 66
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question about rockers and compression
Sorry if this is something super basic or normal, but I sold my old 62 a little bit ago and bought a 1969 short bed. The p.o said the motor was rebuilt 31k ago but when I bought it, it wasn't running. I got it going after I got it home and trying to time this thing was a nightmare. I'm not sure if the cam is degree'd right or what, but I also had some massive valve cover leaks. When I popped the covers, I noticed the intake manifold sat really high and was hitting the valve covers even after they were notched. Is that normal for a RPM Air Gap manifold?
Secondly, some of the rockers seemed a little funky. I've never messed with roller rockers so I don't know what's normal but when they are loose, the only way the roller and valve line up is at an angle, but then I noticed the pushrods were coming into contact with the hole in the head. There seemed to be a lot of debris and grainy stuff in the oil as well. Not sure what is going on there. Lastly, the motor was running all weird, so I took a heat gun and pointed it at all the headers and noticed 2 and 4 were still cold. I checked to see if they had spark and they did. I thought to do a compression test but what I got was : 1: 180 2: 180 3: 180 4: 180 5: 155 6: 180 7:165 8: 180 I'm just lost now and maybe if anyone knows or has any input on any of the three issues I have, it would mean the world to me. Thanks again everyone! [IMG] ![]() intake manifold sitting really high: ![]() the debris in the oil: [IMG] ![]() and the only way the roller rocker lines up with everything at an angle: [IMG] ![]() |
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#2 |
Registered User
![]() Join Date: Feb 2004
Location: brownfield texas (west texas)
Posts: 1,936
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Re: question about rockers and compression
I'm no expert but it looks like a miss match of parts possibly. The intake setting high leads me to believe the block has been severely decked. If the heads were milled a lot the intake bolts would be hard to line up. Also if it was decked or milled that would throw off your push rod angles and lengths. They may also have put copper shims instead of head gaskets which could make .050 difference. Those two holes with low compression could be because valve train is so screwed there a leaky seat.
__________________
The Ghost 67 short wide full custom. 550 hp LSX, 4l80E, narrowed 9". Body dropped w/air ride! ........................ ___ .........________//__{\_____ ,,,,,,,/__(⊙)___//___/__(O)_/ @disciple2.rc 💪instagram💪 LED TAILS |
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#3 |
Registered User
Join Date: Oct 2008
Location: Marianna Arkansas
Posts: 7,269
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Re: question about rockers and compression
You may have a vacuum leak there where the intake is screwed up and no that is not normal. Like already said the deck [or heads] may have been shaved for compression. I think get a push rod length tool and see where the push rods should be. That will help solve the angles and the grainy oil problem.On that note drain and FLUSH that motor out real good before running it any more as those metal flakes are like tiny little grinders doing their thing in that motor. Jim
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#4 |
Registered User
Join Date: Apr 2005
Location: Amarillo, Texas
Posts: 26
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Re: question about rockers and compression
Kind of hard to tell from just looking a pics. but heres my thoughts
1 compression seems to be be high normal should be 140-160 depends on cam, how it's installed, other variables 2 heads, block have been milled extensively with no attempt to correct manifold alignment 3 pushrods appear to be be 3/8" dia., heads need to be clearanced to use them PULL ONE INTAKE BOLT AT THE END AND SEE IF THE MANIFOLD HOLES HAVE BEEN ELONGATED.disregard caps,please |
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#5 |
Registered User
![]() Join Date: Feb 2004
Location: brownfield texas (west texas)
Posts: 1,936
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That's why I don't pay extra for a supposed recent rebuild. You never know what your getting. Honestly I would tear that down and start over measuring the critical stuff first. It's likely other corners were cut.
__________________
The Ghost 67 short wide full custom. 550 hp LSX, 4l80E, narrowed 9". Body dropped w/air ride! ........................ ___ .........________//__{\_____ ,,,,,,,/__(⊙)___//___/__(O)_/ @disciple2.rc 💪instagram💪 LED TAILS |
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#6 |
Registered User
Join Date: Dec 2014
Location: Coal City, IL
Posts: 695
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Re: question about rockers and compression
You can't use pushrods guide plates without drilling out the pushrod holes in the heads. Bad mismatch of parts.
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Tony Nicholas @ Midwest Metal Masters 1953 Chevy 3100 392 Hemi w/727 & 9” Ford 1985 Chevy C/10 6.0L 4L80 373 locker |
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#7 |
Registered User
Join Date: Apr 2005
Location: Amarillo, Texas
Posts: 26
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Re: question about rockers and compression
Shoot, didn't even notice the guide plates. That grainy stuff on your finger is coming from the push-rods ,see pic. You need to pull the engine and get everything right.
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#8 |
Registered User
![]() Join Date: Apr 2014
Location: Oakland, Ca.
Posts: 66
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Re: question about rockers and compression
Thanks so much to everyone for all the great advice. I believe it's time to tear into it and start over. Any tips or suggestions about good gaskets to go with? Thanks everyone!
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#9 |
Registered User
Join Date: Apr 2005
Location: Amarillo, Texas
Posts: 26
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Re: question about rockers and compression
Get it out and apart and let us know what you find. I was a machinist for 30 yrs., and know a little bit about them.
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#10 |
Registered User
Join Date: Apr 2013
Location: South Westerlo, New York
Posts: 1,325
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Re: question about rockers and compression
As far as the RPM Air Gap manifold, I have one on a sbc and its just about flush with the valve cover like the way yours is...
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Thanks, Joe.. 1969 C/10, 348 C.I., 3X2 bbl. V8, 2004r , LWB. |
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#11 |
Registered User
![]() Join Date: Apr 2014
Location: Oakland, Ca.
Posts: 66
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Re: question about rockers and compression
well, i took it apart. As much as it would make life so much easier to pull the motor, my trucks in the very slanted drive way with a small garage filled with 13 motorcycles so I can't really pull it
![]() The pistons are .60 over so clearly it's been rebuilt a few times and that makes me nervous. I found out it had a Comp Cams 268H Cam but some of the lobes look a little suspect. Here's some pics Here's the passenger side cylinders and cylinder head- ![]() And the cylinder head- ![]() Drivers side 1,3,5,7- ![]() And the head- ![]() Also this cam lobe looks unhappy as well as the cam bearing race or bushing ( not sure what the correct name is- ![]() ![]() Any thoughts or advice would be awesome! Thanks everyone and once again, this is the best forum out there! |
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#12 |
Registered User
Join Date: Apr 2013
Location: South Westerlo, New York
Posts: 1,325
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Re: question about rockers and compression
well, its got 202 valves, the cam bearing looks fine in the pic, number 5 combustion chamber looks oily in the quench area, it looks like its running right to the intake valve. maybe a burnt valve or the plug was fouling out making it wet looking. is it the pic or is number 5 plug also wet, can't tell on the cam, how do the lifters look. did you keep them in order to the lobes?
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Thanks, Joe.. 1969 C/10, 348 C.I., 3X2 bbl. V8, 2004r , LWB. |
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#13 |
Registered User
Join Date: Oct 2014
Location: Mesa AZ (Near Phoenix)
Posts: 2,302
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Re: question about rockers and compression
I would not even think about putting that motor back together. Chances are better than average you have had metal running through your oil passages and the crank is probably scarred. Even if you have to take it (or some motorcycles) somewhere you gotta open that bullet up and clean it all out. Did you drain the oil and cut open the oil filter yet?
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"Life is too short to drive a boring vehicle". Later, Wayne ![]() |
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#14 |
Registered User
Join Date: Jul 2010
Location: MD
Posts: 1,937
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Re: question about rockers and compression
Agree scared bearings and oil contamination. The finger image seals the deal.
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1969 c-10 Step Side Long Bed. I-6 250cid = ![]() |
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