pin height

[Challenger340]

The old 440 domed trw/sealed power L2295 had a compression height of 2.029. It was a compression height that doesn't make much sense for a custom 440 piston.
why did TRW do a dome so far down the deck
we always had to deck the block .055 or so to get the pistons closer to 0 deck.
The best reasoning we came up with is trw used the ch of the 68-69 375hp engines and then added the dome and the valve reliefs.. just a theory any way
but if that were the case...
67 replacement would be 1.99
68-69 375hp 2.029

The reason the L2295 Domed Piston was built the way it is(approx .050" down Hole at TDC).... is that it was designed to "act" like a Flat Top at "0" Deck for Compression purposes without the Piston to Valve issues a true Flat Top @ zero deck would entail..... and back in those days cooling/quenching was not a consideration with the better fuels available.
For all intent and purpose...
The DOME volume ~ 12 CC's on the L2295 is the same as if you just had a completely Flat Top Piston @ Zero Deck

We used to mill the Dome off the L2295, drill lightening holes up under the Pin Bosses, and add a set of the lighter "std" piston pins to get them down in the 900's weight-wise.... then as you said we would also Mill the Blocks .055" and run'em under some heavily Ported/Milled 915's to get to 600 hp with a Solid Flat Tappet Cam.
Those were Budget years for sure....

 

[Curiousyellow71]

We used to mill the Dome off the L2295, drill lightening holes up under the Pin Bosses, and add a set of the lighter "std" piston pins to get them down in the 900's weight-wise.... then as you said we would also Mill the Blocks .055" and run'em under some heavily Ported/Milled 915's to get to 600 hp with a Solid Flat Tappet Cam.
Those were Budget years for sure....

Getting those heavy pistons and pins down in 900s is impressive. That had to take some effort. The last 20 years or so they stuck a narrower pin in them to lose a little.

 

[Challenger340]

Getting those heavy pistons and pins down in 900s is impressive. That had to take some effort. The last 20 years or so they stuck a narrower pin in them to lose a little.

"back in the day" LOL.... it was easy/available to just order a set of the P1215 Pins from FM ? could be wrong (I forget the number but around 210 grams) and dump 30-40 grams right away because I still think even today the L2295 Pins are close to 250 Grams aren't they ?

We'd Pin-Fit and run them Pressed Pins in the LY Rods at exactly just .001" interference so we didn't have to do anymore than a 'straw" colored Heat to install.... and .001" clearance in the Piston Pin Bores.... saw LOTS apart after literally decades on the street and NEVER a problem !

If I had a set of L2295's kicking around doing nuth'in today ?
I wouldn't be at all afraid to just call Trend Performance or even KB for a set of lighter Pins to use in the L2295's with the Domes Milled and Pin-Fit off as a budget 1968/9 resto deal under some 2.14/1.81" Valve 906's. I mean crappy quench... but at 9.3 or so CR on an iron head who cares ?
Remember... any Pin 'Flex' under max load only manifests as a problem as the pin ends go 'oval' = galling ? and why Pin-Fitting to the .001" cures any potential problem before it happens.

 

[gtxrt]

i got 1.457 + .545 = 2.002. think i did it right. so 350 horse and 375 hp have the same pin height.

 

[Lefty71]

so 350 horse and 375 hp have the same pin heig

in ` 67 difference was all cam and heads correct??

 

[gtxrt]

in ` 67 difference was all cam and heads correct??

exhaust manifolds and dual snorkel air cleaner, both had 915 heads but 350 hp had 1.60 exhaust valve and not 1.74 like the 375 hp

 

[Lefty71]

Ahhh, I did know about the air cleaner. Had forgorten about the exhaust manifolds. My head was on the C bodies. They did indeed have hipo manifolds for the gtx and rt crowd, as well as the very special ones for the Darts and Barracudas.

 

[gtxrt]

Ahhh, I did know about the air cleaner. Had forgorten about the exhaust manifolds. My head was on the C bodies. They did indeed have hipo manifolds for the gtx and rt crowd, as well as the very special ones for the Darts and Barracudas.

don't forget the chrome valve covers. lol

 

[BSB67]

these are the new race-tech pistons. 2.070 pin height. 12 cc dish. we decked 7 thousand off the block. looks like either ending up with .008 or .018 in the hole . hoping for .018 in hole for less compression

View attachment 1190597

What head? The 915? What is the measured volume?

I think 2.07-ish dished piston (12 cc) at zero deck is a really good combination. Good quench at less than 10:1 CR. But I believe you will be close on detonation with 93 octane. The final combustion chamber volume, cam choice and other details will matter, but I think it is all doable.

 

[gtxrt]

What head? The 915? What is the measured volume?

I think 2.07-ish dished piston (12 cc) at zero deck is a really good combination. Good quench at less than 10:1 CR. But I believe you will be close on detonation with 93 octane. The final combustion chamber volume and cam choice will matter. The details will matter, but I think it is all doable.

915-80cc head. i will be 17-18 thousand in the hole. looking at 9.57 compression so far. cam = [email protected]

 

[BSB67]

915-80cc head. i will be 17-18 thousand in the hole. looking at 9.57 compression so far. cam = [email protected]

Be sure to consult with a cam guy. Someone like PRH or maybe Bob K. if the goal is stock-ish.

 

[gtxrt]

Be sure to consult with a cam guy. Someone like PRH or maybe Bob K. if the goal is stock-ish.

yes stock -ish built. why do you think that cam is not right ?

 

[BSB67]

yes stock -ish built. why do you think that cam is not right ?

I have no idea what your goals are, or the details of the build the cam the car. Therefore, I have no opinion on your cam. If you posted all of the details, me and a bunch of others will give you our opinion, which is always fun, but you need to talk with someone that does this for a living, particularly if you are trying to balance stock-ish, manifolds, compression ratio, horsepower, idle and drive quality....

 

[gtxrt]

here is the set up. 67 Newport, weight 3950. 727 with 2000-2200 stall and mild shift kit. 2.94 posi. would like smooth idle as i can get. hp manifolds with big imperial or hemi mild stock ish mufflers from waldron exhaust. shooting for 9.57 compression with light weight forged pistons 842 grams and thin rings.resized rods with arp bolts with h-bearings. stock valves with performance valve job with un shrouded chamber. 130 seat-310 open pressure valve springs, fast ramp 217-221 with 481-488. lift with 1.5 rockers. no recurve distributor just a little lighter springs so not to cause pinging. stock oil pump not an over kill high volume for this set up. just want a nice quiet driver 440 with more power than stock. hope it pulls to 5200-5500 rpms with power. am old now, had my share of high built motors. did i miss anything lol

 

[RemCharger]

That is a nice car. I had a survivor 67 new Yorker like that not long ago.

 

[BSB67]

here is the set up. 67 Newport, weight 3950. 727 with 2000-2200 stall and mild shift kit. 2.94 posi. would like smooth idle as i can get. hp manifolds with big imperial or hemi mild stock ish mufflers from waldron exhaust. shooting for 9.57 compression with light weight forged pistons 842 grams and thin rings.resized rods with arp bolts with h-bearings. stock valves with performance valve job with un shrouded chamber. 130 seat-310 open pressure valve springs, fast ramp 217-221 with 481-488. lift with 1.5 rockers. no recurve distributor just a little lighter springs so not to cause pinging. stock oil pump not an over kill high volume for this set up. just want a nice quiet driver 440 with more power than stock. hope it pulls to 5200-5500 rpms with power. am old now, had my share of high built motors. did i miss anything lol

View attachment 1191109

Really nice car. I had a 67 Chrysler 300. Still one of my favorites. I would consider another one.

Your cam seems like a good choice for what you have and your goals. A suggestion maybe consider not using a fast rate cam.

 

[Cranky]

In '70, they dished the piston top somewhat to lower the compression. I'm not certain on a '67.

A 350 horse 70 440 that I have has no dish but are .050 down in the hole.....it's still has the original bore. With closed chamber heads and steel shim gaskets, it measures out to 10.3-1.

Getting those heavy pistons and pins down in 900s is impressive. That had to take some effort. The last 20 years or so they stuck a narrower pin in them to lose a little.

With a home made fixture to hold the piston and a ball end mill, it's not too bad. Just takes time. A buddy of mine even ran the goofy gas on them in a mild 440 and ran high 10's in a 3900 lb road runner.....with AC even lol. Heck, can't laugh....used to hit the AC button as soon as I crossed the stripe in my Belvedere. It did bite me once when I forgot to shut it off before rolling up to stage....

 

[gtxrt]

Really nice car. I had a 67 Chrysler 300. Still one of my favorites. I would consider another one.

Your cam seems like a good choice for what you have and your goals. A suggestion maybe consider not using a fast rate cam.

why not fast ramp ?

 

[Curiousyellow71]

A 350 horse 70 440 that I have has no dish but are .050 down in the hole.....it's still has the original bore.

We also have a 70 350hp. Ours is .080 down. Almost sounds like yours either has the 69 piston or someone on the line decided to give it some more umph decking her that day.either seems like a possibility.
@gtxrt
Nice looking car. I think you will be fine with your compression and the cam. But I do think BSB67 is right that your are on the line...you may be running on premium. The fast rate cams will build compression by closing the intake valve sooner they increase the chance of detonation because the engine holds a little more compression. But...it adds some torque down low. Fast rates will usually have higher dcr ..and the dcr equations don't always translate into what is going on with a asymmetric cam. The bad part of pushing compression is that one hot day with a bad batch of gas...

 

[Cranky]

We also have a 70 350hp. Ours is .080 down. Almost sounds like yours either has the 69 piston or someone on the line decided to give it some more umph decking her that day.either seems like a possibility.

Long story short, I bought a wrecked New Yorker with this engine in around 74-75 and sold the engine to my girlfriends brother. He had a 69 Satellite to drop it in but got married and decided to get rid of the car so I bought it. The 440 was in already but there were a few things he did that I didn't like.....like long reach spark plus on one side and short reach on the other....the fan was on backwards and couple of other things so I blew it apart to check it all out. I put the engine away for a later time and sold the body. The engine was very low miles and it didn't have any machine work done to it except a freshen up on the heads but sold those too. I even checked deck height and it was .005 difference across the corners. The block has a 2-21-69 casting date so I suppose it could have got the 69 pistons in it. It now has moly rings, Hemi grind cam, mild ported closed chamber heads with titanium retainers, Hemi/6pack pan and Holley Street Dom intake painted to match. Been waiting on my car for over 30 years now lol. I guess the story wasn't so short after all.....