I really need some help with my Slant, the story is this.

Engine was working right but with some carb problems (1 bbl Holley carb) and small lubrication problem in the head, solved this with another carb and 1 week later solved the lubrication problem.......but in the meantime of carb to lubrication problem, the engine started to work roughly.

Engine was hard to turn on, not a smooth idle, was a little "jumpy", just after the week my slant six was basically working only with 4 cylinders, checked compression in failing cylinders (Number 2 and 5) and was for 95. Car fails under low RPM, but in higher RPMS the problem is null!!.

My mechanic insist in a bad cylinder compression and nothing more, but I really don´t think that can be the problem, can be a valve issue?. I really need help to solve this, many thanks in advance.

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Mopar Muscle is well defend by Slant Six!

Valiant Duster 1971

It would be easy enough to see by rechecking the valve lash (.010 intake and .020 exhaust) cures it. A valve might not be sealing well/leaking and causing the low compression.

Buy another valve cover gasket and re-lash the valves.

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Aggressive Ted

http://cid-32f1e50ddb40a03c.photos.live ... %20Swinger


74 Swinger, 9.5 comp 254/.435 lift cam, 904, ram air, electric fans, 2.5" HP2 & FM70 ex, 1920 Holley#56jet, 2.76 8 3/4 Sure-Grip, 26" tires, 25+MPG

Thanks for the reply Ted, valve lash was checked today and is under correct setting (.010 intake/ .020 exhaust). I was thinking to take off the engine head and check the valves.

_________________
Mopar Muscle is well defend by Slant Six!

Valiant Duster 1971

Do a leak down test. No need to pull the head to test it.

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'72 Duster 198 stock cam, 3:23's Hookers on jack stands for 8 years in the driveway
'79 Maxivan 360 Offy Qjet Comp RV cam/rusting in the driveway.
93 D350 160HP Cummins Auto Dually Clubcab needs a injector pump
2005 Golden Couch Buick

What was the lubrication problem?

CJ

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Part of Tyrde-Browne Racing

95 psi is not too bad. What are the other cylinders? As long as they are not more than 20 psi different, run it.
You could indeed have a valve problem.
As Ceej asked what was the lubrication problem?
Frank

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Scrapple: Because a mind is a terrible thing to waste.
73 Duster - Race Car
66 Dart Wagon - DD
178" FED
82 D150
All Slant powered

Hya Frank!
If I am not mistaken Mopar specs is between 110 and 140 psi with no more than 20 psi diffrence 95 is a bit low

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Regards,
Fanie Gerber
It's never junk, it's just a part you're not currently using

http://www.valiant50.co.za
Just say I own a few Mopars

And what do you mean "under correct setting?"

Tighter than .010" and .020"?

If anything, set them slightly loose. .011" or something like that. Does it have a stock cam?

CJ

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Part of Tyrde-Browne Racing

The rest of cylinders are running a 110 compression, the lubrication problem was almost none oil in the Rocker Arms and Valve Springs area, engine in fully stock. Remembering numbers in compression Cylinder 2 got 92 and Cylinder 5 got 95, the rest are in 110

_________________
Mopar Muscle is well defend by Slant Six!

Valiant Duster 1971

I saw that on my slant in the Dart! It was a rag in there blocking the oil screen!! I hope yours isn't bad!

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'72 Duster 198 stock cam, 3:23's Hookers on jack stands for 8 years in the driveway
'79 Maxivan 360 Offy Qjet Comp RV cam/rusting in the driveway.
93 D350 160HP Cummins Auto Dually Clubcab needs a injector pump
2005 Golden Couch Buick

You might be able to clear the oil passages in the rocker arms with compressed air, or spray lubricant, if you take apart the rocker assembly. It's cheap and easy if it works, the way we like 'em. Also, Rug_Trucker has a good point, a careful compression and leak down test are necessary. Leak down is a compression test with oil sprayed into the cylinder to seal the rings. If the numbers are the same in both tests, the problem is in the cylinder head. If the oil raises the compression, rings are worn. Don't forget to open the throttle plate in the carb while testing compression.