Inline Pro Engine #3 compression/leakdown results
Thread Starter
Joined: Jun 2003
Posts: 2,140
Likes: 162
From: Johnstown, PA
You will ALWAY have air coming out of the dip stick, its normal. You need to verify that high leak down % value isn't from any of the valves or a head gasket leak, again the head gasket likely isn't leaking.
My ILP Stage 2.5x head was pretty good. The valves sealed with the springs removed. I do vacuum tested on the intake and exhaust ports to test leakdown before I assemble an engine.
My ILP Stage 2.5x head was pretty good. The valves sealed with the springs removed. I do vacuum tested on the intake and exhaust ports to test leakdown before I assemble an engine.
Also, during the very first engine rebuild, all of the valve seats were cut out and replaced entirely in my head. Some of them were sunk from botched previous machine work, so I had them just replace them all. Maybe I do have some valves on 2/3 that aren't sealing properly?
Ugh.. the thought of removing the IM with the motor still in the car makes me sad. ha. I should be able to hear something by listening through the TB I hope.
In other news, I replaced both O rings on the dipstick now and I had no idea how worn my old ones were. It's a legitimate pull it takes now to remove the dipstick out. If it pops out now I have some serious issues going on.
Thread Starter
Joined: Jun 2003
Posts: 2,140
Likes: 162
From: Johnstown, PA
You know what the ptw and ring gaps are? If the O-rings are good on the dipstick and you have a couple -10s to the catchcan, it blowing the dipstick up is not good. 20% is a good bit. for reference I'm running .004" ptw and .021" and .028" ring gaps. My leakdown after a short break-in is less than 10% @ 100psi
Inline Pro HD H beam connecting rod set with 3/8" ARP2000 bolts
Stock F22C crankshaft
Piston to wall clearance .003"
1st ring gap .022"
2nd ring gap .026
The lower compression pistons explain the lower compression numbers. They didn't tell me they changed the type of piston to a lower compression one on this build until I just asked for the specs on the motor.
Last edited by Dizings2k; Jul 23, 2020 at 11:44 AM.
Joined: Aug 2016
Posts: 1,154
Likes: 183
From: US129 Maryville, TN
Wait...a FRM bore? I thought this was a sleeved block? 003" is a lot for a FRM cylinder, but is a bit tight for a sleeved one. I dont trust hone/bored FRM cylinders especially with pistons that need coatings added after the fact to make them compatible.
*). Which is why it's impossible to rebore the engine.
Thread Starter
Joined: Jun 2003
Posts: 2,140
Likes: 162
From: Johnstown, PA
No, this is not a sleeved block.
Joined: Mar 2003
Posts: 6,507
Likes: 51
From: Sellersburg, IN
Joined: Dec 2007
Posts: 4,757
Likes: 120
From: Waukesha, WI
Good thoughts. It's been raining hard here but this weekend I'll have a chance to drive the car warm and do this test again. Now that you mention it, I recall the amount of air coming out of the dipstick on Cyl 2/3 being about the same as the "good" cylinders...
Also, during the very first engine rebuild, all of the valve seats were cut out and replaced entirely in my head. Some of them were sunk from botched previous machine work, so I had them just replace them all. Maybe I do have some valves on 2/3 that aren't sealing properly?
Ugh.. the thought of removing the IM with the motor still in the car makes me sad. ha. I should be able to hear something by listening through the TB I hope.
In other news, I replaced both O rings on the dipstick now and I had no idea how worn my old ones were. It's a legitimate pull it takes now to remove the dipstick out. If it pops out now I have some serious issues going on.
Also, during the very first engine rebuild, all of the valve seats were cut out and replaced entirely in my head. Some of them were sunk from botched previous machine work, so I had them just replace them all. Maybe I do have some valves on 2/3 that aren't sealing properly?
Ugh.. the thought of removing the IM with the motor still in the car makes me sad. ha. I should be able to hear something by listening through the TB I hope.
In other news, I replaced both O rings on the dipstick now and I had no idea how worn my old ones were. It's a legitimate pull it takes now to remove the dipstick out. If it pops out now I have some serious issues going on.
Joined: Aug 2016
Posts: 1,154
Likes: 183
From: US129 Maryville, TN
eh, I know a few have had good luck with bored FRM cylinders, but I have yet to see one personally. I've seen a couple of their FRM blocks that have been bored out and rebuilt by them and neither of them lasted more than a year and both were N/A builds. The last one was a street/track car. It was filling the catch can and spitting the dipstick in less than a year.
The only thing I could recommend you try is to get the motor good and hot and try the leakdown again. verify it is the rings and not the valves. .003" is a lot of clearance considering you are working with a cylinder that has an aluminum base.
Thread Starter
Joined: Jun 2003
Posts: 2,140
Likes: 162
From: Johnstown, PA
Well, some good news for once.. albeit minor. I did some WOT pulls today and the dip stick stayed in place completely with the new rings.. and it was oriented normally, not backwards as some have tried.
I’ll try a leakdown test tomorrow and I’ll make sure the motor is as hot as possible. The last leakdown I did was after the car was driven hard but it did sit for about 45 mins before I did the test, so it would’ve cooled a little.
I’ll try a leakdown test tomorrow and I’ll make sure the motor is as hot as possible. The last leakdown I did was after the car was driven hard but it did sit for about 45 mins before I did the test, so it would’ve cooled a little.
