Looking for info on discoed TRW 340 pistons .

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Keven S. Clickner

Keven S. Clickner

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These were part of a pkg. deal when I bought my '69 Dart .
I've done some web searching and found just a bit more than nothing , leads me to believe they have been discontinued for some good length of time .
They are TRW L 2385F-30 .
Here below is the bit o nothing that I found on a fleabay listing , wtf .?
340 CHRYSLER
FLAT TOP WITH 4 RELIEFS
THERE ARE 7 PISTONS THAT ARE " SHINNY" AND 1 THAT IS "DULL"
8 PISTONS, 8 PINS AND LOCKS FOR THE PINS
57CC HEAD---- 9.05 TO 1
60.6CC HEAD--- 8.76 TO 1
63CC HEAD---- 8.56 TO 1
65CC HEAD--- 8.39 TO 1
68.4CC HEAD--- 9.14 TO 1
Mine are all "shinny" and I hope they work out a little more uniformly in the compression ratio department . Somewhat low in compression but i'm sure I can deal w/ that .They are a bit weighty tho at 900g w/ the wrist pin .
Thought I,d find an old pdf doc or something , but no luck sofar . So if anyone here could shed some light with knowledge , old catalog page or something else I'd appreciate it much.
The '69 Dart package also included a '73 340 block , w/ no main caps , forged steel 340 crank , according to my dial caliper has not been turned yet but definitely used . '68 340 intake mnfld. and the AVS to top it off .
Thanks all. a bodies only , a good place to be .
20200919_214445[1].jpg
 
340 Chrysler
L2385F 0030 345cid
Compression Dist 1.740
Flat Top with 4 Valve Reliefs
Deck Clearance .082
68.4cc with 0.39 Head Gasket 8.22
65cc 8.48
63cc 8.65
0.30 over piston weight is 740 grams
This is the information I have found on these pistons , I hope this helps.
 
Yes , thanks any little bit will help . good to know comp height . Lower comp than I thought they may be . Not liken' 'em so much any more .
 
get the mahle forged pistons for a 340 lighter and higher compression . i use them in all my 340 builds
 
The block has had the machine work done . I'm likely going to need something similar, as in a forged piston . Something with like clearances. I've checked 1 location in 1 bore with a telescoping gauge and dial caliper finding a measurement of 4.068 .
There is also the issue of no main bearing caps.
Will a line bore of the mains change anything , or cause distortion.
I need to take it to a shop and have it evaluated. Get a better idea of what I've really got to work with here .
What's it worth ?
I did know the man who started the work. Sadly , no longer among us . I know he knew his **** and loved his Barracudas and going fast .
Just noticed yesterday while doing some cleaning of the block the beginning of some oiling mods possibly . 2 holes drilled and 2 more (I think,or maybe 1) punch marks in the valley.
1 of the drilled holes is on top of the rear rail near dist. opening .
maybe get cpl px of that for tomorrow. Get some input from the consortium here .
And then a thread looking for a good MoPar knowledgeable machine shop near 46310 .
Hughes and Indy aren't far from me but I've read some poor words about both of them recently.
 
A line bore of the mains will put the centerline of the crank and cam a tiny fraction of an inch closer together. That possibly could put a tiny amount of slack in the timing chain, but you can buy a chain that makes up the difference.
 
i've bought lots from hughes , never had a problem all the machining they did for me was good . everything checked out good .Can't say what others have experienced but these days buying parts is a crap shoot with all the crap coming out of china , seen a few complaints about cams bought at hughes who knows my cams were all good . ithink it is more the attitude they take when people get defective parts that people take offence at
 
Nat said:
i've bought lots from hughes , never had a problem all the machining they did for me was good . everything checked out good .Can't say what others have experienced but these days buying parts is a crap shoot with all the crap coming out of china , seen a few complaints about cams bought at hughes who knows my cams were all good . ithink it is more the attitude they take when people get defective parts that people take offence at
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Thank you Nat . Glad to hear something good about Hughes engines. I was going to post a question looking for good reviews, or otherwise.
It's likely impossible to get the true story there's a ***** about everything everywhere. Thats easy . And there's only so much you can help somebody if they can't or won't follow direction you've got to cut them off at some point. Time is money and they can't spend forever on the phone with somebody if they won't listen or can't understand.
 
The line bore must reduce crank CL to deck as well then . ? Are there over sized bearings to compensate?
HaHa. . . . Please heal my ignorance
Thanks all , I'll be back
should I start a new thread with the block?
Or would it fit here as well. Moderator?
 
When it gets line bored, the hole will be the same size. What they do is mill the bottoms of the main caps ever so slightly, and then bore/hone the mains to original specs. You're correct that it does move the crank up towards the deck, but most of the time it is so little that even the timing chain doesn't even need to be compensated. That is only my simple minded understanding of it. I'm certain that a sure enough machinist such as @replicaracer43 or @yellow rose could explain it much better.
 
JDMopar said:
When it gets line bored, the hole will be the same size. What they do is mill the bottoms of the main caps ever so slightly, and then bore/hone the mains to original specs. You're correct that it does move the crank up towards the deck, but most of the time it is so little that even the timing chain doesn't even need to be compensated. That is only my simple minded understanding of it. I'm certain that a sure enough machinist such as @replicaracer43 or @yellow rose could explain it much better.
Click to expand...
Pretty much dead on. Also, small block mopars have a fairly long cam to crank centerline, and as such, a longer chain that tends to stretch. I like running a chain tensioner for that reason.
 
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