a day at track

[TurboCajun]

Went to the track Sunday made one pass and the engine has a knock, Saturday I installed the new TR6 module with new coil pack and put a 66mm turbo on the car and added slicks, The car hooked good and started moving to the wall so I had to pedal, go on it again and it got loose. after looking at the log I pedal 3 times before the 1/8 and never went full throttle after the first pedal.. I guess I got nervous with the slicks making the car wavy. went 11.75 @ 108 not a bad time for pedaling so much and not pushing the pedal to the floor. now on the return road I heard a ticking on the motor and by the time I got back to my truck it was knocking and missing. got back home and pulled the pass side valve cover and the #4 exhaust rocker stud had backed out half way, I inspected the push rod and rocker and they looked good so I bolted it back in and went for a test, it seemed to be fine but once I got into it the car was back firing so I parked it. so I will to compression test and leak down test to check for a bent valve.


Question are 7mm wires big enough for the TR6

[Steve Wood]

they should be...personall y, I always use the largest diameter that I can find...8.5 or 10, but I don't think they are required.  I just liike the look

I don;t think the TR6 provides more spark...it just looks trick and cost more than a house payment

[Scoobum]

TR6 uses 8.5

[TurboCajun]

the reason I purchased the TR6 was back in November the car started back firing and it stopped as soon as I  the spare coil pack on, It did good for a couple of months them started acting up again so I got the TR6 to utilize the new style coil pack and have the rev limiter for safety.


tonight I did a compression test and all cyl where 160-170 psi. after that I did a leak down test and all had 20-25 percent, which is in the green on the tester. I am not sure if that is too much.


So now it has me thinking that I have an ignition issue   


and I still haven't figured out why I have oil being pushed out the breathers, pcv grommet, bolts for the valve covers, and valve cover gaskets. Maybe its the 20-25 % leaks in the cyl.

[Steve Wood]

Keith, 25% is very bad on a performance engine and is worse on a turbo engine.  Most leak down testers seem to use 100 psi for input pressure altho I have seen some that use 80 psi.

First thing we do is to listen at the tail pipes for a leak, then listen at the plenum for a leak, and finally at the pvc valve opening.  If we have a major leak past the valves, we should be able to hear air coming thru the exhaust or back thru the plenum.

If the rings are not sealing, we will probably hear the air coming out of the bottom of the engine thru the pvc valve.

It's very important that the leak down test be conducted with the piston at the top of the cylinder and on tdc so that both valves are closed.  Some people take a short cut by removing the rocker arms and letting the pistons get blown down to the bottom of the cylinder.  As the combustion process is occurs with the piston near the top of the cylinder, that is where the ring seal has to be good.

With all the blow by, it sounds like the rings are not sealed...BUT, if the intake is not well sealed to the heads, you will pressurize the crankcase thru the valley so that means two ways to get blow by-past the rings, or at the intake gasket.

Also, not all leakdown testers are good at being accurate.

The reason that 25% is extra bad on a turbo engine is that we are using 100 psi to see how much air leaks.  On a turbo engine under boost, the cylinder pressure can be in the 1000 psi range so the leakage can be much worse than we would normally expect.

As far as the miss goes, it makes me wonder if a head gasket is giving up the ghost under load...and that should be the fourth was for air to escape. 

[Steve Wood]

Oh, yeah, if the rings are stuck or the gaps are all lined up, this will increase blow by

[TurboCajun]

Steve the leak tester is a cheap one from harbor freight, to zero it out it only took 10 psi them it was plugged into the cyl, the only place I heard air was at the oil dip stick tube

[Steve Wood]

Those have a bad reputation but if you heard air at the dip stick, it's not good. Still, I would look for a better tester

Sent from my LG-H810 using Tapatalk

[TexasT]

Did you put some oil in the cylinder and try the test again? Might bring it up some than we would know it is the rings.

[Forzfed]

That is a good time with all things considered.  How much boost, timing and octane did you use?  Hope you get all your issues figured out!

[TurboCajun]

Used another leak down tester today, for some reason his would not seal tight in the head so there was some leakage at the connection . All 6 cyl were at 20% , so of that 20% some was thru the treads for the spark plugs and the rest was coming thru the valve cover breathers .

forzfed
93 octane, 24psi , 18 degrees top gear timing, with meth

[Steve Wood]

sure is sounding like the rings are not sealing to me

[Steve Wood]

do you hear air out of the covers on all cylinders?

Trying to envision if blown hgs would allow air back into the valve covers-but if the dipstick is blowing out, then the pressure has to be getting into the crankcase

[TurboCajun]

It seemed like it was coming from the covers and the dip stick tube

[Steve Wood]

looks like you are going to have to pull the engine and go thru it to me at this point