Pinto Engine Diagnosis Help

[avakarl]

I have been having some trouble with my long rod pinto engine and im hoping to get some advice in what general direction to go here. I am told this is 3 race long rod engine.


I first noticed on track during a test day. About halfway through the day I started to notice a few puffs of white smoke in my mirror when blipping the the throttle going to first gear. Then I started having trouble blipping throttle and getting it to REV and it started running pretty rough. We came in and noticed black soot on the exhaust pipe and puff of black smoke while hitting throttle. But not white smoke. Then winter came I looked in the CARB and there was black debris in it so I sent the carb of for rebuild and cleaning, just knowing that was the issue. Put the new Carb on have same issues. Sometimes I have white smoke on revs going up but not down and always black smoke while revving. I have also added a fuel filter and have checked that and the carb and there is no more debris.

I took the carb apart and float is set a little high ( the beach is just fully covered) so I intended to get that right but
I decided to do compression and leak down test and got distracted. Compression was done warm and wide open throttle.

1 - 140 4% leak down
2 - 134 6% leak down
3 - 128 10% leak down
4 - 138 7% leak down


I thought the numbers were pretty good. But on cylinder 3 I can definitely feel air coming out of cylinder 4 spark plug hole and a little on cylinder 2 spark plug hole. That confused me since the % is within a acceptable level. also the air from cylinder 4 or 2 does not go into 3.


I took the manifolds off last night and all 4 intake ports and valves are coated with what appears to be slimey oil. the wetness smells of fuel, ( see pictures) all intakes ports look exactly the same. On the exhaust side

cylinder 1 - looks very nasty and oiled up.
cylinder 2 - dry
cylinder 3 (suspect problem cylinder) - is half oil and half dry
cylinder 4 - dry


I briefly spoke to the engine builder and he suggests that all of this is residual symptoms of the float being too high. I am hoping on some feedback to help point me in which direction to go!

Thanks

[CGOffroad]

What fuel are you running in the car? Are you adding anything to the fuel like 2 stroke oil or Marvel Mystery oil ?

Age of fuel cell and age of foam in the cell?

What spark plugs are you running? Mfgr and part number.

[avakarl]

What fuel are you running in the car? Are you adding anything to the fuel like 2 stroke oil or Marvel Mystery oil ?

Age of fuel cell and age of foam in the cell?

What spark plugs are you running? Mfgr and part number.

fuel is the sunoco 100 unleaded with no additives.

spark plugs are NGK AP8FS. I put new spark plugs in this winter and they fouled within 20 min of idling and a trip through the neighborhood.

fuel cell is original, the car is 1999 mygale. I was told the foam was replaced years ago but also that it needs to be replaced again. The debris I am 90% sure was from a cheap amazon fuel hose I had put on for like 5 days as I waited for my pegasus order to come in. I never ran the car with that hose on but when I took if off it was gunked up. As of now no signs of any debris in the filter or carb.

[kea]

Oily residue, check cylinder head.
Valve guides worn, torn or missing valve stem seals?

[avakarl]

Oily residue, check cylinder head.
Valve guides worn, torn or missing valve stem seals?

Keith yea that’s what I’m thinking and hoping. Just strange to me on a more or less brand new motor.

[kea]

Yes, I wouldn't think that should be an issue with a "new" rebuilt engine

[Steve Davis]

I suggest that you check the valve clearances first. Reasonable chance that the intakes (1 or more) just might be too tight? Might also be a combo of both intakes and exhaust.
Steve, FV80

[DaveW]

I suggest that you check the valve clearances first. Reasonable chance that the intakes (1 or more) just might be too tight? Might also be a combo of both intakes and exhaust.
Steve, FV80

Agreed. Tight valve clearances are most likely to occur early in engine's life as things wear in.

[CGOffroad]

It is possible for the cam to get one tooth off on the belt. I think the most common time this could happen is if someone has a stalled engine on track and they 'pop the clutch' to restart engine. I cant remember exact, but one tooth is approx 11º of being off.

What is the best (easiest) way to check that the cam is on TDC with the crank?

If the timing belt ever does get one tooth off what effects do you see from the motor?

[Rick Kirchner]

It is possible for the cam to get one tooth off on the belt. I think the most common time this could happen is if someone has a stalled engine on track and they 'pop the clutch' to restart engine. I cant remember exact, but one tooth is approx 11º of being off.

What is the best (easiest) way to check that the cam is on TDC with the crank?

If the timing belt ever does get one tooth off what effects do you see from the motor?

with standard head and pulleys when you're at TDC there are windows and a pointer on the cam pulley that shows proper alignment.

https://donkiespeed.nl/wp-content/up...eplacement.jpg

[avakarl]

Thanks for the feedback guys. I will start with checking the valve clearances. But do you think with them being tight would cause this type of oil in the ports?

in regards to TDC my cam has notches in it that match up with notches in the head, so with those and the notches on the pully im fairly certain everything is lined up correctly.

[Messenger Racing]

Pull the valve cover first not last. Inspect each rocker and the cam lobes while verifying the valve settings. I have heard there are rockers and possibly cams are floating around that do not meet required hardness requirements.

Good luck,

JM