just tore apart a 383

[rt green]

just tore apart a 383. it had high dome pistons. 30 over. part number L2293. looks like an older rebuild. anyone know what these piston are?

[A383Wing]

L2293F are forged & are advertised as 11:1 comp pistons with 88cc heads & composition gasket

did a search and found that quote above

[BSB67]

L2293F are forged & are advertised as 11:1 comp pistons with 88cc heads & composition gasket

did a search and found that quote above

I believe this is correct.  But measure the dome height and get back to us to make sure.

[c00nhunterjoe]

Those are OLD trw forged pistons. If memory serves, they sit about .020 in the hole
Measure to be sure but running them with the std .020 steel gasket was the trick and got you a healthy 12.5:1 on 915s and 11:1 on 906s. They were heavy, but if balanced and with the 509 cam and opens or 557 cam and closed heads, you could run run 93, spin to 8000 and be king of the street. If you dont use them and they are in good shape, im interested.

[rt green]

this is going to be a street car. got any flat tops for trade?  the TRWs are 30 over

[BSB67]

this is going to be a street car. got any flat tops for trade?  the TRWs are 30 over

Again, measure the domes.

I would not be able to answer the question from here, but there is a chance that you could make that piston work.

[c00nhunterjoe]

Indeed, i wouldnt hesitate putting them in a street car. Choose a cam that is appropriate for the MEASURED AND CALCULATED static compression to give you the desired dynamic compression and you can have a nasty street car. 

[rt green]

i'll measure.

[c00nhunterjoe]

I am extremely curious and borderline excited on this build.What was this engine in? Why did you tear it down? Are the pistons still in the block? What cam is in it?

[rt green]

1970 barracuda. 4 speed . just got it. engine not sealed up very well, but not rusty. no piston ridge. cam looks worn. 30 over. didnt have a socket at home to take off the dampner. can feel a little slop in the chain.  tore into it to see what i have.

[c00nhunterjoe]

Measure the piston height before you tear it down further. That will help immensly with choices. Behind a stick, this could be a nasty street car.

[John_Kunkel]

Pin height on the 2293 is 1.195".

[BSB67]

Pin height on the 2293 is 1.195".

That would put it between 0.020" to 0.025" below an uncut deck, as I think someone already mentioned.

[c00nhunterjoe]

I was going by memory, and i had to really think on it for a while... But at least john's number confirms my memory, PHEW! Lol.

They are a good old school piston in my opinion. If you had to buy new, there are plenty better options nowadays, but these are the right price...

[rt green]

scavenged a few of the measuring tools today. should have what i need for tomorrow nite. 

[c00nhunterjoe]

 

[rt green]

only had time last nite to do part of the measuring. life got in the way. side of the head on the lower pad measures a full inch, so they havent been plained. crushed head gasket thickness was .039. i have to pull out the cherry picker to help lift the engine on the stand to get it level to cc the piston in the block. it just got to late to do that. did clean up a piston top and noticed two flat plaining marks on the upper dome. maybe they took alittle of the top. i was suprised to find no piston ridge at all in the cylinder.

[rt green]

12cc domes 020 down piston height. 906 90 cc

[firefighter3931]

12cc domes 020 down piston height. 906 90 cc

I come up with 9.63:1 using a .040 composition head gasket.

Good candidate for a set of 84cc closed chamber aluminum heads....using the same head gasket the static number is a pump gas friendly 10.23:1 


Ron

[rt green]

thanks guys. cam?

[c00nhunterjoe]

Depending on what cam and what heads you wish to run would dictate what static compression i would suggest aiming for. Are you reusing the stock irons or going aluminum? What headers or manifolds? Whats the total goal for the car before you pick anymore parts. "Street car" is VERY vague in todays world. Keeping the 4 speed? Lots of variables to consider here.

[rt green]

worried about quench with 906 heads. street car. but would like some punch. back and forth to work, fun ect. headers. keep the 4 speed. if i could afford a a set of kb400 pistons,[i think thats the number]  or build one of my 440s right now, i would scratch the trw pistons.     

[rt green]

the only cam i have besides a new stock replacement one is an engle k58/60.   

[BSB67]

worried about quench with 906 heads. street car. but would like some punch. back and forth to work, fun ect. headers. keep the 4 speed. if i could afford a a set of kb400 pistons,[i think thats the number]  or build one of my 440s right now, i would scratch the trw pistons.     

The pistons you have now are as good as anything that KB has to offer, IMO.  There is only one reasonable piston for a 383, and it is not offered by KB.  If your number are correct, you have options.  You cannot get quench, but you still have something to work with.  I would suggest that you double or even triple check your work and results, as a couple of cc's will make a difference on a 383.  Once you've done that, and picking the cam you want, you should be able to hit your desired CR with available head gasket choices.

If your numbers are right, use the 0.040" gasket and a cam like the Crower 271. 

[c00nhunterjoe]

  that will make quite the fun ride at 9.5:1.

Another option if it were mine and you are running 3.91s or 4.10s would be up the compression and go with more cam since its a stick car. The steel shim gasket can get you the needed compression on the 383 to run a steeper cam like the crower 282 or equivalent cam in the low 500 lift and 240's @ .050. If you have 3.55s or less, then go with the 1st cam suggested, even with the 4 speed.

***edit**** seeing the post about having the engle cam on hand- that cam should work well in this engine. I would say no less then a 3.55 gear.