289 Compression Test

[comethead]

Ive been thinking of getting some more fun out of the 289 in my 65. I have a Hipo spec hydraulic cam and lifters, 600CFM Holley, and an aluminum intake I’d like to install.
The engine has been in the car since at least the early 70s (I have maintenance records back to 1971). It runs pretty good. Doesn’t burn oil, pulls ok but it does have a slight miss Ive never been able to fix and I tried it all!
Another thing I need to fix is both front and rear main oil seals are leaking.

Anyhow before doing anything I did a cold compression test and here’s what I got:
1- 125
2- 125
3-120
4-125
5-150
6-140
7-120
8-125

Is the engine worn out?

Would the numbers be higher or lower with the engine warm? I screwed up and took all the plugs out first and didn't warm it up.
Is it time to put her to bed or is it worth doing what I planned above?

Thanks for any help guys.

Joe

[SASSY]

Its only a couple more gaskets (head) seeing as your getting into the top and bottom,,,, besides when did YOU start doing half a jobb lol.
With the range in compression I would think you'll be in there in no time anyway once you start havin fun with it.

[Joe Travers]

Have you ever installed hardened exhaust valve seats, Joe?

Just a SWAG but you may have a problem there.

Joe II

[comethead]

Its only a couple more gaskets (head) seeing as your getting into the top and bottom,,,, besides when did YOU start doing half a jobb lol.
With the range in compression I would think you'll be in there in no time anyway once you start havin fun with it.

Yeah Fred I wouldn’t be doing a head job on it. I’d just pull it and put another engine in.

[comethead]

Have you ever installed hardened exhaust valve seats, Joe?

Just a SWAG but you may have a problem there.

Joe II

Not sure if it has hardened seats or not. Yeah the low numbers aren’t cool

[comethead]

Ive got a rebuilt 302 with an “RV cam” that’s been sitting in the corner for 20 years. Bought it from a friend. It’s been so long he’s not really a friend anymore!
I guess its time to dust it off and see if its any good…

[Lou's Comet]

When you did the compression test did you have the carb/throttle wired wide open?

Seen engines with worse run good long time.

[comethead]

When you did the compression test did you have the carb/throttle wired wide open?

Seen engines with worse run good long time.

I did have the throttle open for the driver side bank not the passenger side
I guess I’ll have to run the test again but the right way. operating temp, throttle open.
That’s good news though that you’ve seen this before and it wasn’t a death sentence! That’s the reason I’m on the fence about this is its running good but the numbers seem low.
Ill report back after a retest.
Thanks Lou!

[Joe Travers]

Not sure if it has hardened seats or not. Yeah the low numbers aren’t cool

I was thinking more on the lines of that 'mystery miss' than the numbers.
If it wasn't missing, I'd throw the goodies to it. But that's just me.

Joe II

[comethead]

Not sure if it has hardened seats or not. Yeah the low numbers aren’t cool

I was thinking more on the lines of that 'mystery miss' than the numbers.
If it wasn't missing, I'd throw the goodies to it. But that's just me.

Joe II

I think Im gonna do just that! See what happens

Thanks Joe!

[Joe Travers]

I think Im gonna do just that! See what happens

You need a Nike sponsorship. Track tires, blown engines,.....

Joe

[poboyjo65]

Joe have you ever run anything like seafoam thru it ?

[Lou's Comet]

When you did the compression test did you have the carb/throttle wired wide open?

Seen engines with worse run good long time.

I did have the throttle open for the driver side bank not the passenger side
I guess I’ll have to run the test again but the right way. operating temp, throttle open.
That’s good news though that you’ve seen this before and it wasn’t a death sentence! That’s the reason I’m on the fence about this is its running good but the numbers seem low.
Ill report back after a retest.
Thanks Lou!

Put the parts on it and have fun!

Lou

[comethead]

I think Im gonna do just that! See what happens

You need a Nike sponsorship. Track tires, blown engines,.....

Joe

[comethead]

Joe have you ever run anything like seafoam thru it ?

I did once a long time ago. Not sure if it did anything. Do you recommend it Johnnie?