Anyone here installed TRW L2322F domed pistons in a 340?

I am a little nervous about installing a set of 340 small block mopar L2322F TRW domed pistons I have because some of the compression figures are showing the flat of the piston above the deck at .017" or .018". I do have two pair of open chamber heads: "O" with 2.02 intake valves and "J" with 1.88 intake valves. Can anyone verify for me by having done this installation already and tell me for sure that there really is room for the piston flat/dome to rise so high above the block surface? I just picture in mind interference of some kind. Thank you very much.

Here are a set for sale if you need a foto:

http://www.ebay.com/sch/sis.html?_nkw=TR...+dart+MOPAR+340

I used them years ago with J heads w/ 2.02 valves no problem with Fel-pro .039 gaskets. What is your main concern? Compression ratio or them physically hitting the head?

Not too worried about compression ratio if I go through with my plan to use a 2.96" stroke billet crankshaft. Figure I am going to loose about a point and a half compression, only looking for 10:1 or 10.5:1 at most. I just could not picture them sticking out of the deck, but .018" is only a little more than 1/64 of an inch. It just seems zero deck height is what most motors shoot for.

On the eagle rod website compression program, I find 10.7:1 with piston .018 out of the hole and 70cc combustion chambers. Same specs but with pistons at zero deck it drops to 10.22:1 (This assumes those pistons have a compression height of 1.84" and the block deck height is 9.599")

Why not just get custom pistons to go with you billet destroked crank instead of using the ancient (heavy) TRWs??

I have two sets and it's for a street motor and I am an old, old school guy. This is a nostalgia build, the 305 was only produced in 1970, newer technology is not the point with this particular project.

The 305 Trans Am racing motors where never "produced" by Mopar, Kieth Black Ent. destroke the stock 340 cranks to make them that C.I. with the T/A, AAR blocks is what I remember being told back in those days by employees at All American racing and Larry Shepard at one of the old Mopar drag seminars
Thinking now about Ma Mopars relationship with Moldex back in those days maybe Moldex made all those cranks to start with so they would work with the stock rod journal sizes instead of using SB Chevy rods and bearings

Mopar Direct Connection had two part numbers for the smaller stroke cranks numbers P3577638 and P4452974. But where they came from is anybody's guess.

I'm pretty sure those are the same pistons in the 340 in my Demon. Has J heads on it w/ a .039" head gasket. Been that way a LONG time.

You will be fine with whats posted here, im doing the same with a 1.77 ch domed piston that .090 out and it still works with the right math.

Just dont spin it super high.

I'm confused....you won't be anywhere near .018 out of the hole with 2.96" stroke more like .150 in.

What you're seeing is normal. Stock 340 pistons in the high compression years stuck out of the block. Mopar engineers were masters at moving the wristpin up or down the piston to get the compression ratio they wanted.

To build a destroker motor you need either a shorter deck height, longer rods or a piston with extra compression height. Which do you have?

R.

I will need to secure longer connecting rods 6.25" - 6.30" to compensate for the shorter stroke.

mill the domes off, much lighter that way, run stock rods and stroke my . When I was in high school I ran a 340 with those pistons....I had to run octane booster or it would diesel. It had 2.02 x heads and a crane 278h cam.

have fun finding a mopar pin size rod that length.

I know what you mean. What I find funny (and frustrating at the same time) is that I remember very clearly back in the summer of 1969 watching men walk on the moon on a black & white television set. see foto:

https://history.nasa.gov/ap11ann/kippsphotos/5869.jpg

But now in 2017, finding someone who can provide a custom set of connecting rods for a small block Mopar just 0.177" (about 11/64 of an inch) longer than factory stock (6.30" vs. 6.123") seems to be an impossible dream.

I think you would be cheaper and better off selling those pistons to someone building a stock stroke motor, buy an off the shelf chevy 6.5 rod and piston combo and turn your crank to match if it already is not a chevy journal. If you really want a short stroke you could use that opurtunity to de-stroke it even more and have a very light weight bob weight and awesome rod/stroke ratio for high RPM use. Best part is those parts are easy to find and very cheap.

I ran those in a 340 for years with "J" heads and T/A heads. It was .016" out with a .039 Fel-Pro gasket, and the heads were milled at least .030". Unless the heads are severely milled the chamber has plenty of room for the piston being out of the block. If you're not confident, mock the engine up and put some clay on the flat "quench" area and turn it over then measure the clay. I think the minimum you'd want to see is about .045" with steel rods, .060" with aluminum IIRC, but there'll likely be more. The dome won't even come close to hitting that part of the chamber.

So no worries with a Mopar casting, but if you're running a different head all bets are off.....