[2manyT/A'S]

[QUOTE=goathead455]

Originally Posted by 2manyT/A'S

MY current HO



Sounds like you've got quite a harem of HO's

You know the story,once you've had an old HO, nothin' ELSE will do!
(and variety IS the SPICE of LIFE)
Can't have TOO many!

[goathead455]

[QUOTE=2manyT/A'S]

Originally Posted by goathead455

You know the story,once you've had an old HO, nothin' ELSE will do!
(and variety IS the SPICE of LIFE)
Can't have TOO many!

I know this all too well.
Just don't start counting how many!!!!!

[speedshopmike]

2many, that wasnt directed at you personally, but thanks nonetheless and i'd be grateful for your help (or anyone else's)

[T/A Fanatic]

SPEEDSHOPMIKE:

Here is my combo. 1971 455 bored to 462. Deck and 191 heads milled to give about 91cc in the combustion chamber. Pistons at zero deck. I'm running a Crower RA IV spec camshaft, installed straight up. Using a 0.039" (compressed) gasket, and TRW pistons, I get between 160 to 175 psi per cylinder (if I remember correctly). The math works out to just about 10:1 static compression. I know this isn't stock, but it should give you an idea for an upper bound.

Alan

[speedshopmike]

thanks, alan.
i'm really looking for a stocker combo's numbers down at 8:1 CR, but that does indeed help nonetheless.
after some tuning, mine can get out of it's own way above 3k rpm nicely, but is still a real slug below.
back in high school, forever ago, i had a 69 a-bod with a 389 and a RA4 cam with 1.5's; it'd melt the tires off the car from idle.
my HO can barely spin the skinny 215/70's that were on it till last week.
speaking of which...

[2manyT/A'S]

I can't recall if you posted this earlier,but what's going on in your diff,ratio wise??

Sounds to me like it might be a combination of too much cam & not enough gear?

[speedshopmike]

3.42's.
most definitely not enough gear for the cam, but in a grossly off-kilter fashion.
as noted previously, i think the cam's incorrectly installed, which is why i'm trying to get compression numbers from someone to see how far off cranking compression is.
other 455's we've done over the years with ra4 cams have plenty of driveable, tire smokey torque; this car doesn't.

[GonicGM]

I didn't thik too much on this but are there no computer programs (desktop dynos) that can tell you number based on the cam specs and intake closing event? At this point, is it worth making a 360 degree timing tape for the balancer, pop #1 or #6 intake and/or exhaust spring, replace with checking spring(s) and verify cam timing events? May not be as accurate as a full wheel but will tell you if you are way out.

[johnta1]

Try this link:

Checking cam timing

From the old HO Racing tech articles.

[speedshopmike]

thanks, guys, i know how to degree a cam.
i'm just looking at causal issues prior to pulling the front of the motor and doing so.

[johnta1]

My link is on how to check the timing of an installed cam without tearing the engine down.

[2manyT/A'S]

Sounds like it's time to get your "fingernails dirty"!

A DEAD torque conveter will give you a VERY soggy bottom end,but your "mystery cam" is likely the culprit.

[OVERULD]

on a different note, IS ANYONE GONNA RUN A COMPRESSION CHECK FOR ME?!?!?!?!?!?
pull ONE easy to reach plug, pull the coil primary wire, and spin it a few times - that's all i'm asking - it takes approximately 6 minutes, in total.
i've helped about a million people on PY - someone wanna return the courtesy please?
some tuning and a tune-up and coil upgrade have made mine a far happier HO - but it still ain't 100% and before i go in and yank the cam for a smaller grind, i'd SURE LIKE TO KNOW WHAT A STOCK HO DOES for cranking compression, please!

Mike:
I'll be glad to try it if you'll give me some more details on exactly what you want. I don't have a compression checker gauge but heck, I probably need one so I'll stop by the local parts store on the way home and buy one. I've got a pretty much stock 71 H.O. and can do it this evening.....on one condition....you have to change your avatar picture....that costume is freakin' me out man....my cat even bows up when he sees it and he ain't skeered of very much...

BJ

[speedshopmike]

johnta1, thank you - i'll have a read tonight.
overuld - thank you as well; that's very kind.
all i want is to pull one plug that's easy to yank, pull coil positive power to disable ignition, hold throttle WOT and crank her over a few times with the tester screwed into the plug hole that was removed.
cold engine, please, to duplicate my test procedure.
note reading on gauge and post it.
you'll be owed a big favor by me; i own the local speedshop, so take advantage of it!
many thanks, fellas.
as for the chaka from "land of the lost" avatar, i gotta stay with my little monkey-boy, i'm sorry - i'm a sleestak on other forums; it's equally creepy.
i grew up watching bad sid & marty krofft tv shows like sigmund and the seamonster, etc.
the eearly 70's were brutal!

-mike

[OVERULD]

Mike:

Here is what I came up with. I bought a compression tester gauge on the way home. Grabbed a cold beer, popped the hood, laid the fender protectors in place, popped open the cold beer, cranked up some Led Zeppelin and pulled the number one plug. I pulled the main wire out of the top of the coil and then installed the compression gauge on #1

I then cranked it for a few seconds and the gauge showed peak pressure of 135 PSI on a cold engine. The only thing I may not have done correctly was hold it a WOT while cranking. I did not do that. If that makes a big difference, I can re-do the test - I have plenty of beer left!

Let me know.

BJ

[njsteve]

WOT does make a difference in the reading. You need an unrestricted air supply into the cylinder for a truly accurate reading. Also, a cold engine will have a different reading than a warmed up engine. The thicker, cold oil can mask some leakdown symptons. Testing as close to operating temperature, with WOT is the most accurate way to get a true reference of the engine's condition.

[OVERULD]

O.K. njsteve, you're right. I rechecked it, this time with WOT, cold engine, # 1 plug and got 155 PSI. So, Mike, does that help?

BJ

[T/A Fanatic]

After seeing OVERULD's numbers, I looked around for my numbers since my estimate seems low. I can't put my fingers on them at the moment, and called a good friend that witnessed my testing. He told me I was too low. He said my cold engine numbers were higher, around 190 to 200 psi, from what he could remember. FWIW.

Alan

[OVERULD]

FWIW, my engine is a pretty much bone stock 71 455 H.O. with the 068 cam, 7041273 Carb, Ram Air, brand new R.A.R.E. exhaust manifolds, true duals with Flowmasters, no H or X pipe, M22 and 3.31:1 rear ratio (A/C car) and it is an absolute torque monster that will melt the tires if you let it.

BJ

[1qikta]

Originally Posted by OVERULD

Grabbed a cold beer, popped the hood, laid the fender protectors in place, popped open the cold beer, cranked up some Led Zeppelin and pulled the number one plug.

Sound like my garage....Trampled under foot...Kashmir..