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Re: 4.15 stroke HEMI
[Re: docford]
#1334585
11/13/12 10:46 AM
11/13/12 10:46 AM
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Joined: Jan 2003
Posts: 9,997
Frostbitefalls MN (Rocky&Bullw...
gregsdart
master
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master
Joined: Jan 2003
Posts: 9,997
Frostbitefalls MN (Rocky&Bullw...
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I run Cp pistons in my motor, custom made. There are other good custom piston makers out there also. I see a lot of room for improvement on that piston/ring/rod setup. If rules allow, anything you can do to reduce rotating weight will help you out. 2.2 rod journals, move the ring pack up tighter to the top, coat the pistons like a Gen III Hemi to keep the rings cool, possibly go to a narrower ring, and finally once you figure out just how far you can move things, the longest rod you can put in the motor to make the piston as light as possible. If you have some flexibility within the rules, then the first thing to do is talk to a custom piston manufacturer and see what they can do for your setup. Rods are available in 7.1 inch long H beams with the smaller 2.2 bearings. There may be longer ones out there. That will leave you enough room for the rings along with some serious weight reduction as you still would have a piston pin compression height of 1.55 for a 10.725 deck height.
EDIT; I just looked at the OLIVER connecting rods web site and they custom make rods to your needs. Pricy, but they are about the best rod made.
Last edited by gregsdart; 11/13/12 10:59 AM.
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Re: 4.15 stroke HEMI
[Re: Hemi SS]
#1334587
11/13/12 03:41 PM
11/13/12 03:41 PM
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Joined: May 2004
Posts: 12,387
Taxes & Virus's R-US, NY
Dragula
I Live Here
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I Live Here
Joined: May 2004
Posts: 12,387
Taxes & Virus's R-US, NY
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Quote:
I have a 4.150 stroke with 2.200 rod journals. I used a 7.100 rod with .990 pins and had Diamond make pistons. Plenty of room between pin and oil ring.
My next one I want to do this way....
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Re: 4.15 stroke HEMI
[Re: 52savoy]
#1334589
11/13/12 04:05 PM
11/13/12 04:05 PM
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Joined: May 2004
Posts: 12,387
Taxes & Virus's R-US, NY
Dragula
I Live Here
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I Live Here
Joined: May 2004
Posts: 12,387
Taxes & Virus's R-US, NY
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Quote:
I used Diamond pistons on my 4.15/6.86.. 477. CompetitionWedge supplied them and went with 9 1/2 cr because of gas, less weight(?) and decked block. Compression works out to about 10.97 to 1!
Rods are 440source 
Diamond will also probably get my next order as well for Hemi pistons. They have some really nice dedicated hemi stuff with comparable prices. We have built at least one hemi with their pistons, and they are nice and light. The JE's I have are quite a bit heavier.
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Re: 4.15 stroke HEMI
[Re: docford]
#1334595
11/15/12 08:27 PM
11/15/12 08:27 PM
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Joined: Jan 2003
Posts: 16,376
dogdays
I Live Here
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I Live Here
Joined: Jan 2003
Posts: 16,376
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Unless you have a cubic inch limit I'd say you got lucky. Those giant Oliver billet rods are he77 for stout. I have been buying part-used-up racing gear for the past few months and roughly half of the pistons have support rings under the oil ring because the pins are in the oil groove. If it's good enough for Sonny Bryant and Rousch Racing it's good enough for me! As a side note, I have a half a set of Crower 7.1s with 4.360 diameter pistons that came out of a ford 460, I bought them for the rods. The rod/piston/pin/ring set weighs just a little more than 100 grams more than the bone stock rod/pin/piston/ring set from a stock 318! I think some of the extremely conservative ideas found among Mopar lovers come from the unconscious attempt to justify the grossly overweight parts found in garden variety Chrysler Corp engines. R. 
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Re: 4.15 stroke HEMI
[Re: RUNCHARGER]
#1334598
11/15/12 11:23 PM
11/15/12 11:23 PM
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Joined: Jan 2010
Posts: 588
Franklin, TN
23T Hemmee
mopar
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mopar
Joined: Jan 2010
Posts: 588
Franklin, TN
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Quote:
JE and Oliver sound good to me. Are you just going to freshen and screw it back together now?
Sheldon
That's what I was thinking too. A 518" Hemi makes for a pretty stout round track motor, even if it was 9 to 1 compression.
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Re: 4.15 stroke HEMI
[Re: RUNCHARGER]
#1334599
11/16/12 06:14 PM
11/16/12 06:14 PM
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Joined: Aug 2010
Posts: 208
Munich, Bavaria
docford
OP
enthusiast
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OP
enthusiast
Joined: Aug 2010
Posts: 208
Munich, Bavaria
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Quote:
JE and Oliver sound good to me. Are you just going to freshen and screw it back together now?
Sheldon
We might go to 4.29" or 4.31" oversize. Two pistons got burned bad when the fuel pressure dropped at full speed in fourth and Me idiot did not lift off the throttle as I wanted to catch that Renault in front of me so bad !! Bummer
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Re: 4.15 stroke HEMI
[Re: 23T Hemmee]
#1334600
11/16/12 06:18 PM
11/16/12 06:18 PM
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Joined: Aug 2010
Posts: 208
Munich, Bavaria
docford
OP
enthusiast
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OP
enthusiast
Joined: Aug 2010
Posts: 208
Munich, Bavaria
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Quote:
Quote:
JE and Oliver sound good to me. Are you just going to freshen and screw it back together now?
Sheldon
That's what I was thinking too. A 518" Hemi makes for a pretty stout round track motor, even if it was 9 to 1 compression.
Oh yes indeed and a drop in compression from currently 11.7:1 to 10.5-10.9:1 is also on the list of to do things. So pistons will be ordered with less dome.
Camshaft is Racer Brown roller with 276°@050 and .629 lift with 1.6 rockers. Would you suggest another roller cam since we are droppig compression ?
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Re: 4.15 stroke HEMI
[Re: docford]
#1334601
11/16/12 10:50 PM
11/16/12 10:50 PM
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Joined: Jan 2010
Posts: 588
Franklin, TN
23T Hemmee
mopar
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mopar
Joined: Jan 2010
Posts: 588
Franklin, TN
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[quote Would you suggest another roller cam since we are droppig compression ?
Kind of hard to say, not knowing the car weight, the type of tracks you're running on, and how much RPM drop in the turns. Doubt there is going to be a "one size fits all" cam, although with that many cubes, it probably isn't going to be quite as critical. Back in the day,('66-68 or so) the NASCAR Hemi's were running the equivalent of the old Racer Brown STX-24 on the big tracks (around .590" lift and 328 total duration) and STX-22 on short tracks (same lift at 312 degrees duration, at least my fading memory tells me that). Not sure how they would equate to the @.050" method but thats just to give you a ball-park comparison. BTW the cars back then were in the 3900lb. range, not sure what yours weighs.
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Re: 4.15 stroke HEMI
[Re: 23T Hemmee]
#1334603
11/22/12 12:58 PM
11/22/12 12:58 PM
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Joined: Aug 2010
Posts: 208
Munich, Bavaria
docford
OP
enthusiast
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OP
enthusiast
Joined: Aug 2010
Posts: 208
Munich, Bavaria
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we checked stroke again and found that it is in fact a 4.15". With that, we have 7.1" Oliver rods and 4.28" custom made JE pistons. The other quite cool things that we found is that the block a vintage HEMI block from 1969 and the alloy heads are 2531110 originals 
Last edited by docford; 11/22/12 01:06 PM.
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Re: 4.15 stroke HEMI
[Re: docford]
#1334604
12/02/12 02:56 PM
12/02/12 02:56 PM
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Joined: Aug 2010
Posts: 208
Munich, Bavaria
docford
OP
enthusiast
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OP
enthusiast
Joined: Aug 2010
Posts: 208
Munich, Bavaria
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Quote:
we checked stroke again and found that it is in fact a 4.15".
With that, we have 7.1" Oliver rods and 4.28" custom made JE pistons. The other quite cool things that we found is that the block a vintage HEMI block from 1969 and the alloy heads are 2531110 originals
heads and block have -M at the end of their casting number, so they are not from back in the day, but recasts from Mopar Performance
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