JDM 302E Engine Owners - Check In!!

[AutoXRacer]

Air fuel at idle and cruise should be 14.7:1 and vary slightly. Bouncing between 13.5 and 15.6 is a big variation. Tip in fueling should start at stoichiometric (14.7:1) and drop down as throttle (load) is applied. How far down will your gauge read? Is 10:1 the lowest it will read, maybe its less...maybe its even 9 or 8:1!? Having a 10:1 AF at tip in will over fuel the engine. Proof is the tops of your pistons. This will wash down the cylinder walls and create ring seal issues. Oil can be pulled back past the rings and up into your intake track when coming off throttle because your seeing so much vacuum at that point, the engine tries to pull oil from any where it can. We think the oil your seeing in the heads is coming from this, after the motor sits when you shut it down it drains into the chamber and sits on the back of the valves and tops of the pistons like you showed in your pictures.

So if this is the case, would it be easier and worthwhile to just replace the injectors, retune, and see if this works instead of taking the motor apart?

I have new injectors on the way.

 

[JimIII@JDM]

So if this is the case, would it be easier and worthwhile to just replace the injectors, retune, and see if this works instead of taking the motor apart?

I have new injectors on the way.

No, fix the problem at hand. If it were my car I would pull the motor, hone and re-ring it and inspect the heads, probably replace the guides and seals to be sure. The replace the injectors and re tune.

 

[AutoXRacer]

No, fix the problem at hand. If it were my car I would pull the motor, hone and re-ring it and inspect the heads, probably replace the guides and seals to be sure. The replace the injectors and re tune.

But then we would never know what the root cause was.

R&Ring the injectors and re-tune is quick and easy. Should the issue then correct itself (hypothetically)?

 

[BadPiggy]

But then we would never know what the root cause was.

R&Ring the injectors and re-tune is quick and easy. Should the issue then correct itself (hypothetically)?

Personal opinion...
I think this is what Jim was referring to.
He's put together more engines than both of us combined.
He's telling you what HE would do...and you're fighting him.

I'd be frustrated too if I were Jim.
Just my opinion.

 

[AutoXRacer]

Personal opinion...
I think this is what Jim was referring to.
He's put together more engines than both of us combined.
He's telling you what HE would do...and you're fighting him.

I'd be frustrated too if I were Jim.
Just my opinion.

I get what you're saying, but R&Ring the engine should be the last resort.
All I'm asking is if the engine is intact, nothing wrong with it, then wouldn't eliminating the rich condition solve the issue?

Why tear into it if there is nothing mechanically wrong with it?

 

[BadPiggy]

I get what you're saying, but R&Ring the engine should be the last resort.
All I'm asking is if the engine is intact, nothing wrong with it, then wouldn't eliminating the rich condition solve the issue?

Why tear into it if there is nothing mechanically wrong with it?

I think eliminating the rich condition will solve the rich condition problem.

My personal opinion, I think you have a sump issue.
Sump issues are typically caused by a vacuum/scavenge problem, somewhere.
Typically, not always.
Did you or JDM install a new oil pump with this build?

 

[AutoXRacer]

I think eliminating the rich condition will solve the rich condition problem.

My personal opinion, I think you have a sump issue.
Sump issues are typically caused by a vacuum/scavenge problem, somewhere.
Typically, not always.
Did you or JDM install a new oil pump with this build?

The whole motor is new...from new bolts to new heads and block.
Nothing in the motor is previously used.

Right now, the only thing that carried over from my previous setup is the A/C compressor and steering pump. Everything else is/was brand new.

 

[BadPiggy]

The whole motor is new...from new bolts to new heads and block.
Nothing in the motor is previously used.

Right now, the only thing that carried over from my previous setup is the A/C compressor and steering pump. Everything else is/was brand new.

I'm not familiar with the 4.6 3V oil pump, but I am familiar with gerotor style oil pumps. If that thing was misaligned or the o-ring(s) get pinched during install, it will create a scavenging problem. Even if it wasn't torqued properly, it'll throw it out of alignment. If it isn't scavenging properly, it's leaving oil everywhere inside that motor.

I just find it hard to believe that 24 valve guides and 24 valve seals are bad. What are the odds?

You can do what you want, you can do what Jim says...but if it were MY motor, I'm going to the oil pump.

 

[o2sys]

What block do they use for the build? Didn't ford discontinue the aluminum 4.6 blocks?

 

[AutoXRacer]

What block do they use for the build? Didn't ford discontinue the aluminum 4.6 blocks?

I got the aluminum 4.6L block...got one of the last ones.

 

[GB10]

If the cylinders are washed down, then you will have no choice but to replace the rings and re-hone. You will usually have scuffed piston skirts and cylinder walls, or maybe polished cylinder walls. Usually the crosshatch in the cylinder wall will be almost gone which means the cylinder walls won't hold oil to lube the rings and piston.

Are your top rings gapless or AP steel?

 

[AutoXRacer]

If the cylinders are washed down, then you will have no choice but to replace the rings and re-hone. You will usually have scuffed piston skirts and cylinder walls, or maybe polished cylinder walls. Usually the crosshatch in the cylinder wall will be almost gone which means the cylinder walls won't hold oil to lube the rings and piston.

Are your top rings gapless or AP steel?

According to the build sheet, they are stainless gapless.

 

[Fabman]

Now, where the hell are all the JDM motor owners!!???

We only have a handful...?

I have 2 JDM 302E's.
One stock headed with mild cams/blower and one CNC headed Big cams/big boost.
Both awesome trouble free motors.

 

[TheKurgan]

We would perform the labor and replace the faulty parts if he sends the heads or entire engine back to us.

If it were me, this right here is what I would do.

 

[dysan]

FYI, I had been getting oil in cylinder #7 last year which never seemed to get worse so I waited until the end of the race season and then pulled the engine. After pulling the engine we found out that all of my driver's side cylinders had become out of round and cylinder #7 was the worst thus allowing the oil to make its was up past the rings into the combustion chamber. We believe that I had a defective block itself and that it had been flexing/shifting.

I agree with the others that you at least need to pull the heads and check the cylinder bores for roundness and wear patterns on the walls. I would definitely re-ring and hone the cylinders at least with this happening.

 

[AutoXRacer]

What did you do with the out-of-round bores? Did you have to get a new block?

ID 1000 injectors due in today!! I already have a start-up tune and will be installing and data logging on Sunday.

I still need to find a reputable machine shop... sigh

 

[dysan]

If it was just one cylinder I would have just had it re-sleeved and be done with it, but all of them on the driver's side were out of round so I'm doing a new build with an iron block I got for free. With them all being messed up it led us all (me, my builder and the machinist) to believe that the actual block was defective and didn't want to chance re-building using that same block.

New build will have manley off the shelf flat top pistons .020 over and will be roughly 11.1:1 compression. Nervous yet excited to see how it runs.

 

[JimIII@JDM]

If it was just one cylinder I would have just had it re-sleeved and be done with it, but all of them on the driver's side were out of round so I'm doing a new build with an iron block I got for free. With them all being messed up it led us all (me, my builder and the machinist) to believe that the actual block was defective and didn't want to chance re-building using that same block.

New build will have manley off the shelf flat top pistons .020 over and will be roughly 11.1:1 compression. Nervous yet excited to see how it runs.

What did you use for head bolts? Ive seen cylinder walls disort from over torquing aftermarket head studs. Around 90 lb/ft the walls begin to distort. The ARP torque specs on their studs is 110 lb/ft We torque the ARP studs, if used, to 20 lb/ft then 70 lb/ft in ford sequence.

JimIII

 

[BruceH]

What did you use for head bolts? Ive seen cylinder walls disort from over torquing aftermarket head studs. Around 90 lb/ft the walls begin to distort. The ARP torque specs on their studs is 110 lb/ft We torque the ARP studs, if used, to 20 lb/ft then 70 lb/ft in ford sequence.

JimIII

That's interesting because as you know using lube on the stud threads increases the applied torque significantly. I have read that Ford designed the mod motor for minimum bore deflection and part of that design incorporates the reliable torque provided by Fords tty hardware.

Don't mind me, just having a "hmmm" moment.

 

[BruceH]

What did you do with the out-of-round bores? Did you have to get a new block?

ID 1000 injectors due in today!! I already have a start-up tune and will be installing and data logging on Sunday.

I still need to find a reputable machine shop... sigh

Don't believe me about ATS in Everett? I'm spoon feeding you here.