Compression? What Does This Mean? - Page 2

**Shane@DBPerformance** · 01-23-2004

There definately was some buildup on the pistons just from looking through the spark plug holes with a flashlight.

01-23-2004

carbon buildup on the piston top leading to higher compression which the rings can't hold and there's excessive blowby.

what do the plugs look like and are they the correct heat range?

**Goat Blower** · 01-23-2004

Hit it with some MCCC.

01-23-2004

mccc works great.....but that might only be a temporary solution

was this a problem before the mods?

what kind of mileage on the stock internals?

SlowWhite · 01-24-2004

Stock Bottom end (replaced at 71K miles ) now at around 112K. 99 Style Head installed recently now has around 28K miles on it.

I never had a logger before. And the last time I hit the dyno to do some tuning was back in 2001. (alot's changed since then, back then my motor only had 20Kish miles)

-brian

**Kracka** · 01-24-2004

Quote:

Originally posted by SlowWhite@Jan 23 2004, 08:55 AM
Tried 2 different compression Testers: (8-15 turns of the motor)
1st one)
-192 across all 4

2nd one)
-189-192 across all 4

8-15 turns is a pretty big difference. Whenver I have done them I usually go about 5-6.

CVD · 01-25-2004

Yeah. Over the course of 15 revolutions I would think that some fuel would probably start to build up in the cylinder. I would try 4-6 cranks and/or hold the gas pedal on the floor when you turn the motor over.

**Kracka** · 01-25-2004

Have you been pulling the MPI fuse when doing the compression tests?

A//// Guy · 01-25-2004

That would prolly be a smart idea.

Enes · 01-25-2004

when i did my test, i pulled the fuse and full throtle, only cranked 4 times and i was getting in the 160 range..

All of the instructions i read anywhere said only 4 cranks.. and you will now that by looking at the Compression tester, the gauge will jump each time.. 4 jumps and you are done. read, write, done.
-E

Iceman · 01-25-2004

On a 2g pulling each injecter harness and the *triangle* harness for the coil pack. The coil pack harness is like right next to the intake manafoild on the right side. I have been up all night so some of this might not make sense.

**Shane@DBPerformance** · 01-25-2004

We did 15 once to see if it would stabilize, we usually did it about 7 cranks with MPI fuse pulled, coil pack unplugged, and throttle open.

**1ViciousGSX** · 01-25-2004

I found my compression readings that I took when I first got my car so I would have a base line to check against if I thought anything might go wrong.

HKS 264/264
Stock cam gears
Warm engine
Fuel injectors unplugged
Coils unplugged
WOT
5 compressions

1) 180
2) 180
3) 180
4) 185

I don't know why #4 was slightly higher, but it was.

**1ViciousGSX** · 01-25-2004

Has anyone checked the cam timing? Having them set to reduce overlap will increase compression. Advancing the intake cam will also increase compression.

**Shane@DBPerformance** · 01-25-2004

His car also runs hot ALL the time. It is stable though, just too hot. I know that is hurting the power a bit. I wonder if there is something wrong with that head like a clogged cooling passage. Is this the same head that was on Nash's 2G that always wanted to run too hot?

Nash · 01-26-2004

Quote:

Originally posted by ecoli@Jan 25 2004, 11:00 PM
His car also runs hot ALL the time. It is stable though, just too hot. I know that is hurting the power a bit. I wonder if there is something wrong with that head like a clogged cooling passage. Is this the same head that was on Nash's 2G that always wanted to run too hot?

Nope that wasn't the head on my 2G when it ran hot. I had the 1G head on it, but I just put a 180 thermostat in it and it helped keep it cooler.

SlowWhite · 01-26-2004

I've been running the stock Thermostat. Which I thought was 180.

I've been battleing this temp issue eversince I swapped the parts to the GSX.

when the motor was in my GS-T I could be cruising at 140mph. And the temp would never move.

However in the GSX if I can barely cruise at 70mph for a prolonged period of time and you can watch the temps climb to around the 223 range.

It's like the car is working way to hard or something?

**Kracka** · 01-26-2004

Sounds like it is probably your GSX's radiator then.

**1ViciousGSX** · 01-26-2004

Stock 2G thermostats are 180 deg

SlowWhite · 01-26-2004

I swapped the radiator out of my GS-T.

But regardless. if the temps don't stop fluctuating during the first month of spring. (ie: test it out again for 1 month) A fluidyne with new Fans will be order.

Any recommendations on Fan?

This set up will eventually need to fit around the FP3065 Set up. (shooting for Sept/Oct 2004)

-brian