UCNTRY

hey this is mainly to xdclevo my the pistons in my motor are L2379 and when you quoted your part number you said they are L2379F now could this mean i have hypers in mine how do you tell the difference between the two

xdclevo

Yeah, i never thought they made a standard, but maybe they do.
I can't even remember if mine had the F stamped on the actual piston. This is what i found on the TRW L2379F. It also answers other things i allways wondered about like valve releife volume and clearance. My spec sheet lists them having a min clearance of 1.5 thou, but at the pin. Less than i thought.
_________________________________________________________________Higher compression, longer life.

Piston, Forged, 4.030 in. Bore, 2-5/64, 1-3/16 Rings, Flat Top, Each

Thanks to a special aluminum alloy that doesn't expand as much as other alloys, these Power Forged pistons are designed to fit tight, providing the stability and ring control you need plus the strength you want. Speed-Pro even added ribbed skirts to them for better oil retention and even includes new wrist pins!

Vendor Sealed Power
Product Line Speed-Pro Power Forged Pistons
Bore (in) 4.030
Piston Material Forged aluminum
Piston Style Flat
Compression Distance (in) 1.647
Dish Volume (cc) 1.50
Valve Reliefs Two
Wrist Pin Style Press fit
Pin Diameter (in) 0.9120
Top Ring Thickness 5/64 in.
Second Ring Thickness 5/64 in.
Oil Ring Thickness 3/16 in.
Quantity Sold individually

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10.70 @ 125.00 on the black fun top
408 Cube Cleveland.

UCNTRY

ok then so is there any way to tell with out taking them out of the bore if they are hypers or should i just take it down to super balance and get them to measure the piston to bore clearence and then get them to crack test the pistons

UCNTRY

so what are the chances of them having a crack wether they are forgies or hypers

UCNTRY

does anyone on here no how to tell the difference

Work Horse

I would have someone check it out for you UCNTRY, crack test as well. That was you know exactly what you have, and may be stop you doing damage to the motor and losing the money you have invested.

davis

The F indicates forged. No letter indicates cast.

:davis:

clevo400

I thought TRW (now Speed Pro) only made the piston 2379 or 2379F as a forged piston to suit the 351 Cleveland with 4V 63cc heads to have approx 10.5:1 compression. I think Sealed power is the name of Speed Pro's cheaper pistons which r cast or hypereutectic pistons. I think anyway !!!

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regards
Stephen

4Vman

while were on the subject does anyone know if the ACL racer series are proper Forged pistons? Are they a good choice for performance stuff?
Some info seems to say they have 2 compression rings while other says they have 1, im confussed!

clevo400

I'm sure ACL Race Series r all Hypereutectic pistons. Think their good for 400-450 hp and 10-10.5:1 comp ratio. The pistons to suit the 6" 302C rod with the 351C crank came with 2 versions. (I think Part No - 9357) The 2 ring piston with 1 comp ring and the 3 ring piston with 2 comp rings. The 2 ring version which I have r good for the weekend warrior with limited street use cos of oil loss but if u change ur oil every 10,000 km it won't matter (u should anyway). Go to ACL website as they have a Tech Bulletin on the pistons.

__________________
regards
Stephen