Thread: Did a CR Test Today!

Well I passed by my friend's garage today and he wanted to see the CR on one of my cylinders as he considers the #'s for his circuit car high and wanted to do a comparison.

He said he just wanted to do 1 cylinder but I told might as well just do a complete test. Even tho I was worried it would show me something to worry about. LOL.

...and it did:

#1 - 240
#2 - 190
#3 - 200
#4 - 230

It was a dry test. And 1st test I ever done on motor so nothing to compare.

A few questions guys:

1. Car feels fine, no smoke etc, but why would my numbers be out so much?

2. What sort of CR would that make my motor be? I heard 20ve is 10.3:1, some say 11:1.

3. What #'s are you guys getting.

Thanks

Peace

Depends on if the gauge is good. I hit 230 with my stock motor before it died. I forget how much a % it should be for it to be with in spec.

230-240 its a good healthy VE anything lower than that it means that there its something wrong mostly valves not sealing properly or bent most of the time....

@ Payu,

Really?

Well if my valves are bent or not sealing, I dont want them to be str8 or sealing at all. LOL

But I am not sure why it's like that and the motor still feels strong.

No problem at all with it.

We cranked the motor 4 times for each cylinder test so I am assuming that the correct way to test.

Peace

No you need to crank it about 10 times per cylinder before the gauge will stabilize and give an accurate reading.

Also you should have the throttle at WOT.

I think you should redo the test.

I usually crank a few more complete revolutions than 4. When the gauge stops moving in bumps, I stop cranking. You should try a wet test in cylinders 2 and 3 and see if the compression bumps up or not. If it does, you've probably got some ring issues. The magic number from lowest to highest compression shouldn't exceed 10%.

my ve did 185 on all 4, but i didnt open the throttle (some say you should) an that was like right after i installed it

That sounds about what mine did.

I also didn't open the throttle. Need to retest.

Dudeman

I once tested a VE motor that was giving 215 across all 4 cilinders also leak test like 3-5% betwen all 4 cilinders and ran fine and everithing and still had like 5 exhaust valves bent so you figure......

A bit off topic here, but what could cause valves to bend? Well to be specific - in a ve with my set up: Calum basic, 3" exhaust, SSAC modded header, 16ve cams with stock came gears.

And of course I am not saying I have bend valves.

Peace