Hi guys, yesterday with a friend we measure the compression in the cylinders of my slanty...

and the results are that on PSI 1/105 2/120 3/120 4/110 5/125 6/105 front to rear

in the manual says that the measure must be on 130 to 160 psi, i can say to you that the head cylinder was rectificated and the gasket is new. the torque on the 12 bolts was 70... my question is that:

Do you belive that the problem is a curve in the block surface?

well... with my friend take the decision to dismantle the engine and replace the piston rings, take the block to rectificate and change all gaskets.

y hope that resolve the problem of boiling because yesterday drive for 3 streets and the water falling out of the plastic pot at side of radiator.

do you believe that decision is right.

thanks for all folks!!! XD

PD: if i dismantle the engine i will up some photos of the process.

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dodge aspen 79 AT

Check the valve lash, then rechack compression. If the numbers are about the same as before resetting valve lash, you need to have valves reground.

Richard

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Part of Tyrde-Browne Racing

If the problem is with the block surface, I think it would act like a leaking head gasket. If the engine oil is white and foamy and there is overheating, that might indicate the problem you are talking about. Low compression is a sign of valve or piston ring wear(deteriorado). You can try the compression test again after spraying some oil in the spark plug hole. If the numbers stay the same it is valve wear. If the compression increases with the oil, the rings may be worn.

Agreed, do a leakdown test.
Regardless you'll have to pull the head.

Hi Palazzo, what manual do you use?
According to the '78 manual, all your cylinders are within specs! Olaf.

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Aspenized

hi and thanks for your time,

well... the head cylinder was rectificated the intake valves was reground and the exhaust valves are new... i don´t think the valves was the situation.

and the valve lash is ok...

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dodge aspen 79 AT

hi and thanks, i can tell you that the oil is normal but the water jumps away when accelerate without the radiator cap, this maybe the gasket... but the gasket is new, maybe the head cylinder bent... not because was correct the surface, i think the best is to rebuilt the engine and don´t suffer anymore...XD

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dodge aspen 79 AT

When you checked compression, did you have the throttle wide open? If the throttle plate was closed, you will get low readings.

Other thoughts:
This could be due to bad rings.
What is the condition of your timing set? A loose chain can play havoc with readings.
Does the cam show excessive wear? Do you have the ability to check the lobe lift?

Lots of things to check. Have you tried a wet compression test? If the numbers come up in range, it points at rings as previously pointed out.

CJ

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Part of Tyrde-Browne Racing

Olaf: i have a manual in spanish, the only sure is in the first page say "grupo 9, MOTOR, contenido" in english maybe group 9 ENGINE contents... and the text of the ESPECIFICATIONS chapter say "presion de compresion con motor caliente, bujias quitadas acelerador todo abierto a un minimo de velocidad de manivela de 150 RPM : 9,13 a 11,24 kg/cm2 (130 a 160 Lbs/pulg2(psi))" and "variacion maxima entre cilindros (cualquier motor): 1,40 kg/cm2 (20Lbs/pulg2(psi))"

what can i do? in what manual can i believe?

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dodge aspen 79 AT

Maybe Dan can help with this one. There may have been spec differences between various origin country engines. Where were the engines built for this vehicle?

CJ

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Part of Tyrde-Browne Racing

CJ thanks, i think the rings and the block is my problem, because the timing set is ok the cam does not have wear and the chain is firmly yet... the wet compression test is putting oil in the hole... of the spark plug...? because i did it too and the compression up a little but not considerably... i think is the block... well thank for your time and support.

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dodge aspen 79 AT

the plate in the driver door says made in usa... is the only that i can say

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dodge aspen 79 AT

Translation to English---

"Group 9, MOTOR, content" in English maybe group 9 ENGINE contents ... and the text of the chapter ESPECIFICATIONS say "compression pressure with hot engine, removed spark plugs throttle fully open to a minimum speed of 150 RPM crank: 9.13 to 11.24 kg/cm2 (130 to 160 lbs/in2 (psi)) "and" maximum variation between cylinders (all motor): 1.40 kg/cm2 (20Lbs/pulg2 (psi)) "

Richard

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Part of Tyrde-Browne Racing

RESET VALVE LASH...RECHECK COMPRSSION....throttle wide open....THEN ADD TABLESPOON OF OIL TO CYLINDERS AND RECHECK COMPRESSION ...if it jumps up then you need rings....dought very much you have bent /warped the block

Palazzo, the original information about pressure is from the US factory manual '1978 CHRYSLER PLYMOUTH DODGE Chassis-Body Service Manual'. The pressure is given in psi, the info in the spanish version is in metric units kg/cm². Maybe there could have been some confusion abot conversion factors in the original translation?

It makes me curious; where is the engine assembled? If not in the USA, is you manual an original issue from the assembly plant?

Olaf.

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Aspenized