Compression test fustration

Davidrad · Nov 3, 2019

I have a 67 belvedere with a 383 and the HP exhaust manifolds. How the frick do I manage to get a compression tester into the spark plug holes. Do you have a recommendation on testers that allow for almost 0 clearance and can be done blind since the manifold is in the way. My testers all have about 8 inches of hose connected. Basically I need a fitting that threads in to the spark if holes and then I can connect a qd to.

Kern Dog · Nov 3, 2019

Every tester that I have seen uses a black hose with a brass or steel threaded fitting at one end and a quick disconnect for the gauge at the other end.

BB BELLA · Nov 3, 2019

as kern dog stated the black hose with fitting on the end is smaller and more pliable than anything else your going to come up with! It's definately a 2 handed job, maybe use the phone a friend option if your not ambidextrous! consider yourself lucky your not trying to do it on a side by side marine engine setup,standing on your head!

69L48Z27 · Nov 3, 2019

I’ve found working from under the car helps being able to see the plug holes. The right bank is challenging, also try standing in front of the car and reaching back under the manifolds, I can get to the first three plugs that way.

Bee1971 · Nov 3, 2019

Top or Bottom

Bottom is best by far

Davidrad · Nov 6, 2019

I had exhaust leaks anyway so I just took the HP manifolds off. Life got much easier then. But the test didn't give me good news.

Fran Blacker · Nov 6, 2019

Think KD meant a tester that screws into spark plug hole.

Don Frelier · Nov 6, 2019

Put some oil in #5 and test again. If it stays low you may be able to get away with re-working the heads.
If it comes up...
Well then you are in for a rebuild.

BSB67 · Nov 6, 2019

Unfortunate. The "better" numbers are bad, and the bad number is worse.

Davidrad · Nov 6, 2019

Don Frelier said:
Put some oil in #5 and test again. If it stays low you may be able to get away with re-working the heads.
If it comes up...
Well then you are in for a rebuild.

I forgot to say. I did the oil trick and it didn't come up. I'll be removing the heads once I get back in town and taking them to a shop. Or buying a cheap 440 on CL and taking my chances. Can't go wrong with more displacement.

Davidrad · Nov 6, 2019

BSB67 said:
Unfortunate. The "better" numbers are bad, and the bad number is worse.

Agreed. Pretty sure the valves have sunken into the head.it does explain why it didn't pull very hard.

dadsbee · Nov 6, 2019

I do it all the time.. but I'd have to explain what XX/80 determines most likely..

Durandal25 · Jul 31, 2021

dadsbee said:
I do it all the time.. but I'd have to explain what XX/80 determines most likely.. View attachment 861557

i just saw this….lol, awesome

Carcinogen · Jul 31, 2021

dadsbee said:
I do it all the time.. but I'd have to explain what XX/80 determines most likely.. View attachment 861557

Plus you can hear where compression is leaking out.

440 Charger · Aug 4, 2021

Davidrad said:
I have a 67 belvedere with a 383 and the HP exhaust manifolds. How the frick do I manage to get a compression tester into the spark plug holes. Do you have a recommendation on testers that allow for almost 0 clearance and can be done blind since the manifold is in the way. My testers all have about 8 inches of hose connected. Basically I need a fitting that threads in to the spark if holes and then I can connect a qd to.

Its one of the weidr things you just do it.

Compression test fustration

Davidrad

Well-Known Member

Kern Dog

Life is full of turns. Build your car to handle.

BB BELLA

Well-Known Member

69L48Z27

Well-Known Member

Bee1971

Well-Known Member

Davidrad

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Fran Blacker

FBBO Gold Member

Don Frelier

FBBO Gold Member

BSB67

Well-Known Member

Davidrad

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Davidrad

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dadsbee

FBBO Gold Member

Durandal25

Well-Known Member

Carcinogen

Well-Known Member

440 Charger

Well-Known Member

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