compression

[johnmi]

Should Snyders 5.5:1 Model A head have more Compression then a regular head. Mine is 60 60 60 55 Thanks John

[Mike V. Florida]

yes

[johnneilson]

John,

Cranking cylinder pressure is not really relative to C/R.

So many factors combine to the cranking pressure that it is only a comparison from cyl to cyl.

Adding compression, or increasing the C/R is going to add performance.
At some point, the increase can be detrimental, ask around here, but be honest.
The condition of the base motor and the intended use are instrumental to success.

If the rings are worn, bearings/Babbitt is questionable then adding compression is just likely to finish off the motor sooner.

John

[Kurt in NJ]

try a different compression gauge, I have seen a lot of variations, ones with long rubber hoses tend ot read lower because the hose swells

[Ron W]

Make sure the throttle is wide open and all plugs removed. Ron W

[Bob Bidonde]

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A 5.5:1 compression ratio should yield at least 80 to 95 psig on a good running engine. A stock 4.2:1 compression ratio should yield 60 to 75 psig.

[harleynut]

Bob is dead on right. I have two As. One with a Snyder 5.5:1 and one stock. The stock reads 60psi and the 5.5:1 reads 60

[harleynut]

Misprint 5.5 reads 90

[BILL WILLIAMSON]

Compression test:
Engine warm & just ran.
FULLY charged battery.
Crank it at least 10 strokes or until the gauge quits rising.
AND, remember that ALL gauges don't read the same!
Bill W.

[johnmi]

How can I identify a 5.5: 1 Snyder's head on an engine I bought that was sold as having a Snyder's head? Thanks, John

[jkassay]

Mine is a stock head. Two compression gauges.... One says 50# all across, The other says 70# all across. It appears the average should be OK! Darned gauges, probably a third would be even different.

[Mitch//pa]

Get a snap on and it will read accurately

[BILL WILLIAMSON]

Are we just trying to get HIGHER READINGS for BRAGGIN' RIGHTS?? If it runs well, JUST DRIVE IT!!!
Bill W.

[johnmi]

Bill. If it was running right I would not be asking these questions John

[BILL WILLIAMSON]

Originally Posted by johnmi

Bill. If it was running right I would not be asking these questions John

John, forgive me if I offended you.
Bill W.

[Brian T]

Originally Posted by johnmi

How can I identify a 5.5: 1 Snyder's head on an engine I bought that was sold as having a Snyder's head? Thanks, John

My Snyders 5.5 head has a small circle with 5 dots in the casting on the left side, the 6 to 1 has 6 dots.

[johnmi]

Brian My Synder head has 2 small circles with 5 dots in each circle on the driver side Thanks John

[Henry's Lady's Man]

Originally Posted by BILL WILLIAMSON

Compression test:
Engine warm & just ran.
FULLY charged battery.
Crank it at least 10 strokes or until the gauge quits rising.
AND, remember that ALL gauges don't read the same!
Bill W.

I just used an old gauge that's followed me around for over 40 years since my college days. It has a tapered rubber plug that you hold in tightly. I got readings of 40-40-45-45.. HOLY GUACAMOLE! Your tips give me hope, since I tested a COLD engine. I also have this old P.O.S. gauge that may be way off.
I guess if I'm THAT low, I could use a heavier oil or an old-engine additive.
Thanx fer the good tips. Chuck