Today I did compression test and gues what I find

[Slow5.0]

Lke topic saw I did compression test today because I have some problems with engine and this is what I find

#4 135psi #8 145psi
#3 135psi #7 148psi
#2 133psi #6 147psi
#1 135psi #5 145psi

I repeat 4 time each cilynder first without oil and with oil and every time same results
So my 302 stay under the hood
Anyway I still tryin find out whats wrong and why I sometime engine run with less cilynder

What compression you guys have
My Stang have 100K miles , daily driven and saw the track around 80 times and one crazy driver

 

[1105]

The passenger side seens a little low. All of my cylinders got around 150-155psi

 

[mto502]

Mine all ranged between 155 and 170 but I have smaller CC heads. From what I understand with stock heads and your mileage those numbers are normal.

 

[Stump1000]

Seth, did you ever check your fuel pressure?

 

[red94fiveo]

Mine all ranged between 155 and 170 but I have smaller CC heads. From what I understand with stock heads and your mileage those numbers are normal.

True, but don't you think its a little unusual that ALL the passender side heads are 10 PSI less than the drivers side. I'm going to have to agree with Zach on this one, all those numbers may be normal for his engine/mileage, but the pattern between passenger side and drivers side is what I would be curious about.

 

[Rootus]

Those are normal numbers for a stock headed 5.0, but you shouldn't read anything into the absolute values anyway, it's pretty meaningless. Consistency is all that counts, and it looks like you're okay in that regard.

Dave

 

[Slow5.0]

Thank you guys , I think my rings are still good because when I add oil psi didn't jump , but I have plan to get some cheap heads , like ported iron Gt-40 from a Cobra
Did anybody know can I use stock iron GT-40 heads from 93 Cobra

 

[DougNuts]

Did anybody know can I use stock iron GT-40 heads from 93 Cobra

Yes you can.

 

[Fast94Cobra]

i think i got around 152-143 on my 132,000 mile long block

 

[VIPERn94Five-0]

Those are normal numbers for a stock headed 5.0, but you shouldn't read anything into the absolute values anyway, it's pretty meaningless. Consistency is all that counts, and it looks like you're okay in that regard.

Dave

Bingo....you shouldnt flip out if the numbers seem a little low...as long as they are consistent across the board your cool....iwould say your compression is fine....
....every time i go out into my garage i see my compression tester sitting on my toolbox....but im so deathly afraid to touch it lol...basically cuz i just dont wanna know if my compression is bad...my friends and I always joke about it when were working on cars...we look at eachother and pick it up and are like "hey wanna compression test your motor?" and whoever were asking is like "no way in hell"....

...back on topic..when you say sometimes the motor runs without a cylinder exactly what do you mean??....im pretty sure ive read that you checked them but are you sure its not an issue with a plug, plug wire, injector, cap/rotor? something like that being FUBARed up on the #8 cylinder could cause that...


Anthony

 

[Slow5.0]

OK GUYS , my friend is Mustang guy he build a lot Mustangs and he have 10sec 94 Stang , today he spend half day in tryin find out whats wrong and he check everything from , dist cap, wires rotor(from his Stang ) , did comprassion again , check like 10 times injectors puls on injectors every f****** thing but cilynder #8 is DEAD ne heat on header for some reason so he come up witj : comprassion is good when is cranking engine but when its running its lean down 100%
So next what he gonna do is take apart f****** heads and see what is bad , demaged pistons, ring or valves or something else
So I been thinkin there is a few choice
Build 302 with SVO heads and GT intake for $2500
331 Stroker kit
Fixed what is broken (if is piston or rings) and buy some nice used alu heads
Or buy Stock engine from wracked Stang with low miles
I'm short with money very short , next monday going check out can I get some money / loan like $2500
What you think guys

 

[Black70Fastback]

got a valve sticking on that cylinder? it looks good on a cranking comp test but, cant close fast enough when its actually running? just an idea.

i dont think it would be rings. as the motor gets warm all that stuff expands and would if anything, seal better, not worse.