'not detonating with regularity'....

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nm9stheham

nm9stheham

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I saw this posted on another automotive forum and it just floored me..... thought your guys would appreciate this part of a post by a guy who thinks he know what he is doing:

"I didn't mention all of the attention and tests that the tuner gave to cylinders 1+2. He showed me that cylinder #2 was clearly not detonating with regularity and was fouling and missing intermittently, even though it had excellent compression and new plugs/wires/cap/module. He felt that this was actually caused by a blown head gasket between 1+2 or a valve issue. Blah, blah, blah,....."

Not detonating with regularity?!? He had posted earlier that he and the tuner has measured 210 psi cranking compression on cylinder 2, 3, and 4! When I posted that was way too high for an iron headed NA engine.... he just kept on going....:wtf: Not the first time this guy has ignored solid advice.... and he wonders why his engine is having issues.

You just never know....
 
nm9stheham said:
I saw this posted on another automotive forum and it just floored me..... thought your guys would appreciate this part of a post by a guy who thinks he know what he is doing:

"I didn't mention all of the attention and tests that the tuner gave to cylinders 1+2. He showed me that cylinder #2 was clearly not detonating with regularity and was fouling and missing intermittently, even though it had excellent compression and new plugs/wires/cap/module. He felt that this was actually caused by a blown head gasket between 1+2 or a valve issue. Blah, blah, blah,....."

Not detonating with regularity?!? He had posted earlier that he and the tuner has measured 210 psi cranking compression on cylinder 2, 3, and 4! When I posted that was way too high for an iron headed NA engine.... he just kept on going....:wtf: Not the first time this guy has ignored solid advice.... and he wonders why his engine is having issues.

You just never know....
Click to expand...

Any surprise? Happens here every day. Remember the guy who refused to find TDC recently? You caint fix stupid.
 
nm9stheham said:
I saw this posted on another automotive forum and it just floored me..... thought your guys would appreciate this part of a post by a guy who thinks he know what he is doing:

"I didn't mention all of the attention and tests that the tuner gave to cylinders 1+2. He showed me that cylinder #2 was clearly not detonating with regularity and was fouling and missing intermittently, even though it had excellent compression and new plugs/wires/cap/module. He felt that this was actually caused by a blown head gasket between 1+2 or a valve issue. Blah, blah, blah,....."

Not detonating with regularity?!? He had posted earlier that he and the tuner has measured 210 psi cranking compression on cylinder 2, 3, and 4! When I posted that was way too high for an iron headed NA engine.... he just kept on going....:wtf: Not the first time this guy has ignored solid advice.... and he wonders why his engine is having issues.

You just never know....
Click to expand...
Hey wait a second. My Swinger doesn't detonate regularly.
 
My 367 takes off like somebody lit a fuse under it, but there is so much noise and smoke and howling and roaring, that it would be really hard to hear regular detonation, nevermind the irregular kind. I'm just not in tune with that kind of thing,lol. Besides, she could drop a cylinder or maybe two and I still might not notice until third gear............ I feel sorry for those 4-banger guys.
 
nm9stheham said:
I saw this posted on another automotive forum and it just floored me..... thought your guys would appreciate this part of a post by a guy who thinks he know what he is doing:

"I didn't mention all of the attention and tests that the tuner gave to cylinders 1+2. He showed me that cylinder #2 was clearly not detonating with regularity and was fouling and missing intermittently, even though it had excellent compression and new plugs/wires/cap/module. He felt that this was actually caused by a blown head gasket between 1+2 or a valve issue. Blah, blah, blah,....."

Not detonating with regularity?!? He had posted earlier that he and the tuner has measured 210 psi cranking compression on cylinder 2, 3, and 4! When I posted that was way too high for an iron headed NA engine.... he just kept on going....:wtf: Not the first time this guy has ignored solid advice.... and he wonders why his engine is having issues.

You just never know....
Click to expand...
My street first hemi had 203-205 straight from the factory-------------
 
famous bob said:
My street first hemi had 203-205 straight from the factory-------------
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Which is waaay off from the FSM..... '65 FSM cranking compression spec for the 426 with 10.3 SCR is 130-165 psi..... right at what I would expect. I think your gauge musta been busted!
 
AJ/FormS said:
My 2014 Orlando measures ~220 on my guage; 2.5liter VVT
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And SCR is probably up around 11 and with the VVT and maybe direct injection, it is gonna read that. This guy has just a standard 70-80's type cammed CIH Opel engine, NA carbed.
 
Hyup and this past week the intake-cam phaser has been sticking, and today it finally stuck too far advanced, which causes the engine to want to stall at take-off like a dirty TPS or MAP sensor. Shoot, now I have to look at that, and the wife needs the car on Monday to go to work:(
 
nm9stheham said:
Which is waaay off from the FSM..... '65 FSM cranking compression spec for the 426 with 10.3 SCR is 130-165 psi..... right at what I would expect. I think your gauge musta been busted!
Click to expand...
Nope, when I switched to superstock, the c.r, dropped to about 180 if I remember right, "bigger cam" !
The street hemi`s didn`t have much cam at all stock. Back then a well known drag racer from Ark. tyold me his all did about the same , he was pretty well off and had factory backing ,
 
famous bob said:
Nope, when I switched to superstock, the c.r, dropped to about 180 if I remember right, "bigger cam" !
The street hemi`s didn`t have much cam at all stock. Back then a well known drag racer from Ark. tyold me his all did about the same , he was pretty well off and had factory backing ,
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Well, you can't say that the FSM does not say what it says... it is right there in B&W: 1965 Plymouth FSM. I don't know what to think..... the FSM and my experience say one thing, you say something completely different... For the life of me, I can't figure out the reason for the difference.

You're talking about cranking compression in PSI, right? Stock factory pistons that came in cars sold off of the showroom floor, or did you have some sort of different high CR pistons in there for drag racing? Running a high octane fuel mix maybe? Just trying to make sense of this....tnx.
 
nm9stheham said:
Well, you can't say that the FSM does not say what it says... it is right there in B&W: 1965 Plymouth FSM. I don't know what to think..... the FSM and my experience say one thing, you say something completely different... For the life of me, I can't figure out the reason for the difference.

You're talking about cranking compression in PSI, right? Stock factory pistons that came in cars sold off of the showroom floor, or did you have some sort of different high CR pistons in there for drag racing? Running a high octane fuel mix maybe? Just trying to make sense of this....tnx.
Click to expand...

Yes , all the plugs out cranking by battery till the needle quits moving , usually about 3 maybe 4 rotations ---------.
Factory 68 roadrunner hemi, had 13,000 on it when I first bought the drivetrain . The hemi`s seemed to have a descretion in piston height and compression ratio`s , in what the factory and the nhra stated.
For legal nhra racing they had a set maximun piston height , it was pretty weired compared to a stock hemi , and I cant explain it .
Don't care what the manuals say , experience is the real deal to me -------I didn't get to check the second st. hemi , it was a basket case when I bought the satellite it belonged to.
The solid lifter /stock cam only had .495 lift. In a 3900# belevedere it was pretty stout , we tried running stock class with it first = 7" tires , that was a joke !
 
Sounds like maybe you had the higher compression 12.5:1 version..... that I can easily see having the cranking pressure you found.
 
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