firemn131

Getting ready to pull the engine for MM/OPG, TB/WP, Refresh..etc..

I wanted to get some base line compression numbers. All are close to each other..
However, here is the range. From 97 to 108..
Car runs great, aren't these numbers off by about 100?

so, what are the compression #'s supposed to be.

I ran the car and had it up to operating temp. Parked it and had all plugs out in 10 minutes. Compression tester in, WOT turned for about 6 turns..

thnx

SeanR

Why are you pulling the engine/

Lizard928

Compression tests aren't very good. A leakdown test is a far better engine check.

Agreed with Sean, why pull?

rgs944

You could do a lot better job of cleaning but I would sure not pull the engine to do what you are planning. Have you been to Dwaynesgarage site yet?

firemn131

Yea, I know I can do all of that with the engine in. But it is so filthy and wiring needs work, I just want to clean the engine and bay.

After I pull the engine, I am bringing in my sons 968 to do a FOES. I found his car in a junk yard for $2000.00. the mechanic who had it couldn't figure out the variocam system. I think I can get this car running for about 300..
I am in no hurry to have the 928 back on the road...just gonna make it perfect..Plus to be honest, I have found that you learn so much when you pull the engine..The best part is that my 12 year old son is gonna get schooled.

I was wanting to do a leak down, but couldn't find the correct gauge set up.

I have been to Dwayne's and have made binders of lots of his info..

I am also doing a power steering rebuild.

FredR

I typically see about 185 psig and pretty much even numbers at that last time I tried it.

Have you calibration checked your gauge at all? I usually crank my engine about 3 seconds. If that was your real compression pressure I think you'd be driving a sick car.

Regards

Fred

joejoe

When testing did you hold throttle open?

Dan87951

Wow, your engine seems tired. Do a follow up leak down test as well. Have you been in a proper running 928? I bet if you did you would be amazed at the power increase.

fraggle

Mine was, cold, 193-195 with new headgaskets.

firemn131

I ran the car and had it up to operating temp. Parked i5 mph and charge ont and had all plugs out in 10 minutes. Compression tester in, WOT turned for about 6 turns..


I am thinking the gauge must be bad..Car runs great...it will break loose at 35 mph and charge on. rolls easily past 140...idles great, doesn't burn or use oil. I wont drive it at all on wet roads. it just has so much torque, the slightest bit of too much pedal on a wet road and we in for a wild ride...

firemn131

new gauge..good results


172-183