'74 AMC 304 Right Bank Smokes When Hot.

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They all use umbrella seals from the factory. CHeck your PM.

Bob
tufcj

Thanks, didn't know that.

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Bob, I am going by Summit on Tuesday and Ashley wants to replace her VSSeals as well when we do her intake/headers etc.

I'm not sure what size the stock valves are.

Do you know?

Thanks,
Jim

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OK, did a compression test (WOT) on Jr's 304 and we need some help here w/the results.

Results Drivers Side Front to Back (no smoke from this side):
122-clean plug
122-clean plug
125-plug a little fouled
105-clean plug

Results Passenger Side front to Back (big time smoke from this side):
116-clean plug
125-clean plug
115-plug fouled big time
125-clean plug

Seems like the passenger side cylinder is the one that's doing all the smoking.

He is running a Autolite 65 plug and we want to try a hotter plug but not sure what number to run. I called O'Reilly and the guy suggested a Autolite 866.

We would like to try the hotter plug so he can drive it to the pressure wash station before we do a valve job.

Any thoughts?

Thanks,
Jim

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WET test all plugs in as before except the cylinder in question. WOT.

Results Drivers Side Front to Back (no smoke from this side):
122-clean plug
122-clean plug
125-plug a little fouled
105-clean plug - Added some WD-40 and the cylinder went up to 110lbs.

Results Passenger Side front to Back (big time smoke from this side):
116-clean plug
125-clean plug
115-plug fouled big time - Added some WD-40 and the cylinder went up to 124lbs.
125-clean plug

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OLD NUMBERS

Results Drivers Side Front to Back (no smoke from this side):
122-clean plug
122-clean plug
125-plug a little fouled
105-clean plug

Results Passenger Side front to Back (big time smoke from this side):
116-clean plug
125-clean plug
115-plug fouled big time
125-clean plug

That plug came w/the Jeep.

I installed new plug wires and Autolite 65 plugs.

Still smokes out of the right bank.

I let it idle for a while to maybe burn the oil oil out of the cylinder (maybe 10min). Then I drove it around the 3 acres and it kept smoking.

I then stopped and help the throttle @ about 1500 rpm and punched it a few times. Big time smoke and also when I took my foor off the accellerator pedal I did see some smoke (not much but visible in the daylight) coming out.

Here are the new compression numbers with ALL the plugs out/WOT/engine cold.

NEW NUMBERS
Drivers side front to rear:
118
125
126
105

Passenger side front to rear:
119/120
122
100
130

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Jr's Jeep is a 3spd/304 and I have a question.

Question, if he pulls a 360 that has a auto behind it, can he take the pressure plate (where the clutch rides/motor turns the tranny) off the 304 and bolt it to the 360 or does he have to get one for a 360?

Question, will the same work for a 401?

Also, will his bell housing will bolt up to the 360 and the 401?

Thanks,
Jim

[tufcj]

The cylinders are a little unbalanced, but the compression numbers are good enough that I wouldn't think the rings are bad enough to produce that kind of smoke.

The bellhousings are all the same on V-8s.

On the flywheel/flexplate, AMC V-8 engines are externally balanced. The flywheel/flexplate/harmonic are unique to the displacement. 304 and 360 use the same stroke/rods, so they are close, but the balanace is slightly different because of the additional weight of the bigger 360 pistons. I've heard of guys getting away with a 304 flywheel on a 360 or vice-versa, I've also seen one with vibration so bad it cracked the bell housing. Is it worth tearing down twice if it vibrates? Up to you, but I would just find the right flywheel/flexplate and do it once.

Bob

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that is what I'm thinking about the ring.

I'm going to do a leak down test.

Thanks again,

[tufcj]

What intake are you running? Factory style valley pan? I've seen poorly sealed manifolds suck oil from the lifter galley, from paper gaskets instead of the valley pan, re-used valley pans, or poorly machined aluminum manifolds.

Bob
tufcj

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Running stock 2bbl intake factory.

Leakdown test today-I don't have the tester so I'm going to put about 15psi in each cyl on TDCand listen.