The Forward Look Network
The Forward Look Network
Search | Statistics | User Listing Forums | Chat | eBay | Calendars | Albums | Skins | Language
You are logged in as a guest. ( logon | register )

Old Hemi Parts
Jump to page : 1
Now viewing page 1 [50 messages per page]
View previous thread :: View next thread
   Forward Look Technical Discussions -> Engine, Exhaust, Fuel and IgnitionMessage format
 
Powerflite
Posted 2019-01-17 10:58 PM (#576965)
Subject: Old Hemi Parts



Expert 5K+

Posts: 6491
50001000100100100100252525
Location: So. California
I just got a great deal on this collection of new hemi parts. It includes a full set of brand new 331 10:1 compression pistons, a full set of brand new 392 hemi Mickey Thompson aluminum rods, and a brand new 392 hemi camshaft made to 300D specs.

The rods are about .015" short from standard 392 hemi length. They measure out at 6.942", whereas standard length is supposed to be 6.956". I assume that's to account for the extra thermal expansion of the aluminum vs. the iron. The difference in expansion between 7075 aluminum & cast iron is about 13.1 ppm/C, and assuming that the temperature goes from 20C to 260F or 126C, - a 106C range, that gives a length change of .14% or a final length of 6.952". It's still a little short, but close enough that it is plausibly correct.

The cam is brand new and just what I need to get one of my 392 motors running well. People say that rebuilding old hemi motors is expensive, but I would have to disagree. The reason is because of the wide availability of old speed parts like these that can be obtained very cheaply. I paid around 15% of what this stuff would have cost me if I were to purchase them new. You do have to know what you need, well in advance of when you need it though, because it takes time to find them.



(New Hemi Parts.jpg)



Attachments
----------------
Attachments New Hemi Parts.jpg (238KB - 66 downloads)
Top of the page Bottom of the page
Powerflite
Posted 2019-01-17 11:14 PM (#576966 - in reply to #576965)
Subject: RE: Old Hemi Parts



Expert 5K+

Posts: 6491
50001000100100100100252525
Location: So. California
The Jahns pistons are in a 3 7/8" size, according to the box, and 10:1 compression on a Chrysler. I measured the skirts on them to be 3.87" so the box label seems to be correct. But what is odd is that the box says they are STD. Usually that means standard size, but 3.875" bore isn't standard for any hemi motor. The 313 Canadian poly has a standard bore of 3.88, but these definitely have a hemi dome to them, so I seriously doubt they would work in a poly. If I ignore that STD label, these should work in a 60 mil overbore 331, and I am hoping that's what they were intended to be used in. I tried doing a search for the 8-942H TP part number, but came up empty.

The old paperwork on these parts is really neat. I will scan them and include them here for future reference.

Edited by Powerflite 2019-01-18 12:23 AM




(331 Hemi Jahns Pistons.jpg)



Attachments
----------------
Attachments 331 Hemi Jahns Pistons.jpg (157KB - 65 downloads)
Top of the page Bottom of the page
Powerflite
Posted 2019-01-18 12:05 AM (#576967 - in reply to #576965)
Subject: RE: Old Hemi Parts



Expert 5K+

Posts: 6491
50001000100100100100252525
Location: So. California
M/T Aluminum rods instruction sheet.



(MT Aluminum Rod Instructions.jpg)



Attachments
----------------
Attachments MT Aluminum Rod Instructions.jpg (246KB - 64 downloads)
Top of the page Bottom of the page
Powerflite
Posted 2019-01-18 12:07 AM (#576968 - in reply to #576965)
Subject: RE: Old Hemi Parts



Expert 5K+

Posts: 6491
50001000100100100100252525
Location: So. California
Jahns Pistons Instruction sheet (both sides).



(Jahns Pistons Sticker.jpg)



(Jahns Pistons Instructions pg1.jpg)



(Jahns Pistons Instructions pg2.jpg)



Attachments
----------------
Attachments Jahns Pistons Sticker.jpg (88KB - 64 downloads)
Attachments Jahns Pistons Instructions pg1.jpg (244KB - 60 downloads)
Attachments Jahns Pistons Instructions pg2.jpg (246KB - 64 downloads)
Top of the page Bottom of the page
ToMopar
Posted 2019-01-18 2:35 AM (#576977 - in reply to #576965)
Subject: RE: Old Hemi Parts



Elite Veteran

Posts: 875
500100100100252525
Location: D-70199 Heslach
Powerflite - 2019-01-18 3:58 AM

......People say that rebuilding old hemi motors is expensive, but I would have to disagree.
......it takes time to find them.


Nathan, you're a lucky guy
Top of the page Bottom of the page
57burb
Posted 2019-01-18 5:39 PM (#577005 - in reply to #576977)
Subject: RE: Old Hemi Parts



Expert

Posts: 3732
2000100050010010025
Location: DFW, TX
Lots of Hemi stuff out there, but the issue is getting someone to sell it. And of course, the price when you do. That's a good score!

I have an old nos Isky cam for a 392, and a set of Ansen main straps for one too. If I ever build a drag engine I'll put them in there. Good stuff!
Top of the page Bottom of the page
hemidenis
Posted 2019-01-18 7:21 PM (#577009 - in reply to #576965)
Subject: Re: Old Hemi Parts



Expert

Posts: 3718
20001000500100100
Location: Northen Virginia
Yes, i'm the ones that assured that restoring a HEMI is very expensive. I did one and with many NOS parts, one of them was a complete NOS set of connecting rods that were listed in Gary Goers catalog for about 12 years and nobody care to purchase.

I faxed Gary and he said, "yes I have 16 of them NEW in the box" I purchased all of them, used 8 and sell the other 8 for a fortune on ebay with more than 26 bidders fighting for it. Also found a NOS engine damper, power steering, oil filler cap, crank pulley, bypass hose, oil sump, water pump impeller, main and rod bearings.

Yes parts are there, I'm just waiting to Gary to go back to business and wait if he print more NOS hemi parts on his catalog. Ha!










Edited by hemidenis 2019-01-18 10:57 PM
Top of the page Bottom of the page
wayfarer
Posted 2019-01-21 11:29 AM (#577168 - in reply to #576965)
Subject: Re: Old Hemi Parts



Elite Veteran

Posts: 820
500100100100
Location: Central Ory-Gun
Nice find!
Top of the page Bottom of the page
Mopar1
Posted 2019-01-23 10:55 AM (#577271 - in reply to #577168)
Subject: Re: Old Hemi Parts



Expert

Posts: 2788
2000500100100252525
Location: N.W. Fla.
Some years ago there was a set of NOS Jahn's in the OEM box for a 331. Buyer didn't know what the C/R was, so I took a chance & won them. I found the C/R on the box. 13:1. Sold them to a vintage drag racer in Ca.
Top of the page Bottom of the page
Powerflite
Posted 2019-01-23 2:25 PM (#577277 - in reply to #576965)
Subject: RE: Old Hemi Parts



Expert 5K+

Posts: 6491
50001000100100100100252525
Location: So. California
Wow 13:1, that's in the Alcohol range. On these, I think I was just as pleased with the old instructions as I am with the parts. These 10:1 331 pistons are gonna be great in the '55 Imperial motor currently installed in my '56 Plymouth.
Top of the page Bottom of the page
ToMopar
Posted 2019-01-24 5:27 AM (#577320 - in reply to #577009)
Subject: Re: Old Hemi Parts



Elite Veteran

Posts: 875
500100100100252525
Location: D-70199 Heslach
hemidenis - 2019-01-19 12:21 AM
I'm just waiting to Gary to go back to business and wait if he print more NOS hemi parts on his catalog. Ha!


Denis, do you know if Gary sold that parts to Quirey? Or do he still have those kind of parts.
Top of the page Bottom of the page
Stroller
Posted 2019-01-26 10:30 AM (#577400 - in reply to #576965)
Subject: Re: Old Hemi Parts


Veteran

Posts: 195
100252525
Hm. When I re did my 354 hemi it was not easy but I found Fel Pro Sealed Power jugs and nope were not cheap. Found a guy from the machine shop that new someone whose grand dad was into racing back in the 50-60's and was a mopar nut. Seems that with so many people starting to use the old hemi's there would be more parts re-pops. Folks are getting stuff somewhere.
Top of the page Bottom of the page
mikes2nd
Posted 2019-01-26 12:17 PM (#577409 - in reply to #576965)
Subject: Re: Old Hemi Parts


Expert

Posts: 4151
200020001002525
i think Quirey bought everything.
Top of the page Bottom of the page
hemidenis
Posted 2019-01-26 9:23 PM (#577428 - in reply to #576965)
Subject: Re: Old Hemi Parts



Expert

Posts: 3718
20001000500100100
Location: Northen Virginia
yes Tom Gary sold everything.
Top of the page Bottom of the page
Powerflite
Posted 2019-03-11 12:52 PM (#579171 - in reply to #576965)
Subject: RE: Old Hemi Parts



Expert 5K+

Posts: 6491
50001000100100100100252525
Location: So. California
I compared my stash of 392 hemi pistons that I have. I had always thought that the Jahns pistons that I ran in my '68 Barracuda throughout high school were 10.5:1 compression, and I was told that the Venolia pistons I purchased with my '58 Imperial motor were the same 10.5:1 ratio. I have never verified either of these claims. The Arias pistons have a part number on them and I remember calling them to find out they were 11.2:1. All of this makes me doubt the advertised compression of the stock '58 pistons. The difference in compression height between it and the '57 pistons is very small. I will measure it and do a calculation to see what it comes up with but something seems off here. I realize that the taller forged pistons have larger valve reliefs so it's hard to make a direct comparison without looking at displaced volume, but nevertheless, something is a little odd here.

I am thinking of building a .0625" oversize 354 motor for my Savoy and so I am thinking of possibly using these stock '58 pistons in it. If they are indeed 10:1 in a 392, then they would equal out to about 9:1 in a 354, and with 331 heads, I would get to about 9.5:1. But if they aren't really that good, I don't want the compression ratio down to less than 9:1, so I would be forced to get custom forged pistons for it. Anyone have a set of 11.5:1 392 pistons in standard size they would like to sell? I would use those Arias pistons in it, but they are .03" oversize so that would be a stretch in the 354. The Venolias are .08" oversize! and all set to go into my '58 motor.



(392 Pistions.jpg)



(392 Pistion Heights.jpg)



Attachments
----------------
Attachments 392 Pistions.jpg (144KB - 45 downloads)
Attachments 392 Pistion Heights.jpg (182KB - 45 downloads)
Top of the page Bottom of the page
58coupe
Posted 2019-03-11 9:33 PM (#579210 - in reply to #576965)
Subject: Re: Old Hemi Parts



Expert

Posts: 1455
10001001001001002525
Location: Alaska
Nathan, are you sure the 58 392 pistons would work OK in a bored out 354? I have a 57 354 poly i am converting to a Hemi and using 331 heads and i also don't want the C.R. too low. Is it still possible to get 354 hemi pistons in at least 9.5 to 1?
Top of the page Bottom of the page
jboymechanic
Posted 2019-03-11 10:00 PM (#579212 - in reply to #576965)
Subject: Re: Old Hemi Parts



Expert

Posts: 1848
100050010010010025
Location: Muskego, WI
I'm running standard bore 10:1 compression 392 Hemi pistons in my 1956 354 hemi. My block needed at least 0.050 bore to clean the cylinders, easiest piston to source was 392 pistons as they are 0.0625 over standard 354 bore as Nathan said. My car runs beautifully. I'm guessing that I'm at about 9.5:1 compression after having the deck and heads machined true. I have the details written down in a book... somewhere.
Top of the page Bottom of the page
Powerflite
Posted 2019-03-11 10:00 PM (#579213 - in reply to #576965)
Subject: Re: Old Hemi Parts



Expert 5K+

Posts: 6491
50001000100100100100252525
Location: So. California
The problem is that people offer replacement pistons only. Dumb!! That means that you can only get the compression ratio that was originally offered in the motor back then - which was 9.0:1. I believe that later marine or truck pistons don't help you out either because they were listed at 8.2:1 compression. If you want higher compression pistons you have to get a custom forged piston. With those, you can get any ratio you want, but they cost around $700-$800.

But yes, standard bore 392 pistons work fine in a .0625" overbore 354 motor. But using them makes you lose about 1 compression point when swapping to the 354. You can gain 1/2 a point back by going from 354 heads to 331 heads (or aluminum). So if '58 392 pistons actually give you 10:1 compression, then you can get 9.5:1 compression that way. But you can also get the same compression by using replacement 354 pistons in any size, with the 331 heads. So you aren't gaining anything by boring it out, except potentially being able to use cheap used pistons like these.
Top of the page Bottom of the page
wayfarer
Posted 2019-03-12 8:00 PM (#579261 - in reply to #576965)
Subject: Re: Old Hemi Parts



Elite Veteran

Posts: 820
500100100100
Location: Central Ory-Gun
The current crop of castings are indeed oem c/r and some do not even make the advertised number. Buyer beware.
The best route is to use a custom forging...no, not inexpensive.
If you can tolerate the lower c/r then hog out the 354 and use std 392 pistons.
I'll suggest that you play with the numbers before buying 392 pistons to be sure that is a viable solution.
Top of the page Bottom of the page
ToMopar
Posted 2019-03-14 7:57 AM (#579308 - in reply to #576965)
Subject: Re: Old Hemi Parts



Elite Veteran

Posts: 875
500100100100252525
Location: D-70199 Heslach
Something went wrong on this forum,- look on the date
Top of the page Bottom of the page
Powerflite
Posted 2019-03-14 8:09 PM (#579332 - in reply to #576965)
Subject: RE: Old Hemi Parts



Expert 5K+

Posts: 6491
50001000100100100100252525
Location: So. California
I compiled data from different piston manufacturers to compare them to each other. I found data on Arias, Ross, and Keith Black. It was kind of annoying that none of them provided compression ratios at the same combustion chamber volumes. The ratios that are published by the manufacturers are enclosed in green. For your information, an uncut 392 head is typically around 110cc, 354 at 105cc, and 331 (& HH aluminum) at 100cc. If you mill them, the volume goes down from there. To create CR numbers at the same combustion chamber volume, I derived the equation at the top of the picture to fill in all the missing blanks.

You can use the equation to predict the change in CR if you use a different piston dome volume too, to see how the Ross numbers would predict what the Arias piston CR would be. By doing this, the Ross pistons seem to be assuming a thicker head gasket because it's numbers are consistently lower than the others, but the Arias & Keith Black numbers agree with each other pretty well. Notice that using the Keith Black pistons in a standard 392 head results in a best case 9.5 CR. If you use a thicker head gasket like Ross, you will end up with 9.2 CR. But these are typically advertised as being 10:1 and are based off the same design as the Egge aftermarket and stock '58 Chrysler pistons.

This tells me that if I use Egge or KB 392 pistons in a 354, that I would likely be getting around 9:1 (or less!) with 331 heads unless I cut them, and deck the motor to increase it. One unknown here, though is the stock Chrysler piston dome volume. If the stock valve reliefs are significantly smaller on the stock pistons, then maybe that could bump up the CR a bit from the reproduction versions. I will try to measure that on my motor to get a good estimate to compare it here. But it looks like Chrysler may have over-estimated their compression ratios on these motors. We'll see when I measure it out.

Edited by Powerflite 2019-03-15 12:02 AM




(Piston CR Comparison.jpg)



Attachments
----------------
Attachments Piston CR Comparison.jpg (146KB - 41 downloads)
Top of the page Bottom of the page
Powerflite
Posted 2019-03-14 11:45 PM (#579359 - in reply to #576965)
Subject: Re: Old Hemi Parts



Expert 5K+

Posts: 6491
50001000100100100100252525
Location: So. California
Using the Deck Height of a 392 hemi at 10.877" and the above information, you can calculate the Deck Clearance and resulting compression ratios directly. It is:
Deck Clearance = Deck Height - Stroke/2 - Rod Length - Compression Height.
You get:
Arias: .017" Deck Clearance, gives advertised results with .023" gasket thickness
Ross: .022" Deck Clearance, gives advertised results with .033" gasket thickness
Keith Black: .032" Deck Clearance, gives advertised results with .010" gasket thickness!!

Looks like the Ross numbers are the only ones that make sense with realistic gasket thickness. If you use the same .033" gasket that Ross uses,
the Arias CR with a 110cc head results in a ratio of 9.82.
The Keith Black results in a ratio of 9.04! That's a long ways off the advertised value!
Top of the page Bottom of the page
wayfarer
Posted 2019-03-15 12:17 PM (#579378 - in reply to #576965)
Subject: Re: Old Hemi Parts



Elite Veteran

Posts: 820
500100100100
Location: Central Ory-Gun
I have yet to find a 'shelf' piston that makes advertised c/r in whatever application it is made for. Strictly speaking EarlyHemi here.
Egge is probably the worst but, for a reason. Egge bought all of the molds for the Hemi stuff from 'X' after 'X' bought the entire Hy-Duty operation simply to add to their
sbc production capacity . They basically discarded all other production. Egge then decided, I assume, that having both 57 and 58 pistons was not needed so they now only make one.
It is further assumed that they either just called the 57 10:1 or they made changes to the 58 molds for some reason. Although they make a decent piston it is not even close to 10:1.
Top of the page Bottom of the page
Mopar1
Posted 2019-03-15 2:51 PM (#579383 - in reply to #579378)
Subject: Re: Old Hemi Parts



Expert

Posts: 2788
2000500100100252525
Location: N.W. Fla.
From what I've seen the OEM numbers are optimistic on low deck engines.
Top of the page Bottom of the page
Mopar1
Posted 2019-03-15 2:52 PM (#579384 - in reply to #579308)
Subject: Re: Old Hemi Parts



Expert

Posts: 2788
2000500100100252525
Location: N.W. Fla.
ToMopar - 2019-03-14 6:57 AM

Something went wrong on this forum,- look on the date
Jan. 17, 2019????
Top of the page Bottom of the page
Shep
Posted 2019-03-15 4:18 PM (#579390 - in reply to #579384)
Subject: Re: Old Hemi Parts



Expert

Posts: 3158
200010001002525
Location: Chestertown, NY ( near Lake George)
Without ccing the combustion chamber for a volume reading, the specs are nominal at best.
Top of the page Bottom of the page
Powerflite
Posted 2019-03-15 5:01 PM (#579395 - in reply to #576965)
Subject: Re: Old Hemi Parts



Expert 5K+

Posts: 6491
50001000100100100100252525
Location: So. California
I know that the specs will change with different volume, but the numbers should at least match what they advertise, and they should use a gasket thickness that is most common in doing so. The fact that those Keith Black numbers are a 1/2 point off is completely unacceptable in my book. Add to this the perception that they are 10:1 replacement pistons, with a whole point of compression off, makes it even worse.
Top of the page Bottom of the page
Powerflite
Posted 2020-04-27 9:04 PM (#597438 - in reply to #579395)
Subject: Re: Old Hemi Parts



Expert 5K+

Posts: 6491
50001000100100100100252525
Location: So. California
I modeled the stock pistons the best I could to determine the expected compression ratio from them with a .033" head gasket thickness and 110cc head volume for the 392. I got:
1957: 8.6:1
1958: 9.4:1
Keith Black: 9.04:1
Ross: 9.25:1
Arias: 9.82:1

Disappointing to say the least. I was thinking I was going to get 10:1 with the '58 pistons, when I'm really lucky to get 9.4:1. Wayfarer, does this match what you have found? I did a reality check to see what I would get if there were no valve reliefs, and no bevel on top of the '57 piston, as if it were just a flat top up to the same height as the original. Even doing that, I only get 9.1:1 compression on the '57 version. Still shy of the advertised 9.25:1. Engineers should be smarter than that, so why did they screw it up so badly?

Edited by Powerflite 2020-04-27 9:42 PM
Top of the page Bottom of the page
51coronet
Posted 2020-04-28 1:48 PM (#597467 - in reply to #576965)
Subject: Re: Old Hemi Parts


Extreme Veteran

Posts: 326
10010010025
That is dissapointing Powerflite. I put the kb pistons in my 392 build thinking I would be closer to 10.
Top of the page Bottom of the page
wayfarer
Posted 2020-04-28 2:17 PM (#597470 - in reply to #576965)
Subject: Re: Old Hemi Parts



Elite Veteran

Posts: 820
500100100100
Location: Central Ory-Gun
Your numbers are just about what I would have expected.
Although a 'bandaid', and if you still want 10:1, you might consider using an aftermarket 2.0 or 2.2 con rod with an offset grind to push the piston up a wee bit.
It won't take much and you get a new premium rod.

Gary
Top of the page Bottom of the page
Powerflite
Posted 2020-04-29 3:17 AM (#597494 - in reply to #576965)
Subject: Re: Old Hemi Parts



Expert 5K+

Posts: 6491
50001000100100100100252525
Location: So. California
Another way to bump up the compression would be to run aluminum or '55 331 heads with 100cc chambers. That would bump the Keith Black pistons up to 10:1. You would just have to use the intake adapters & deal with the longer crossover length. I believe that a true 10 or 10.5:1 compression piston using a 392 head looks more like the dome that is on the forged Jahns or Venolia pistons in the previous picture I posted. There's quite a bit more dome volume on those than on the other available pistons. And I ran those Jahns pistons shown there with the aluminum rods for many years in my Barracuda on regular pump gas and never had any ping or pre-ignition problem with them.
Top of the page Bottom of the page
Mopar1
Posted 2020-04-29 1:17 PM (#597512 - in reply to #597494)
Subject: Re: Old Hemi Parts



Expert

Posts: 2788
2000500100100252525
Location: N.W. Fla.
Powerflite - 2020-04-29 2:17 AM

Another way to bump up the compression would be to run aluminum or '55 331 heads with 100cc chambers. That would bump the Keith Black pistons up to 10:1.
But...the alloy is so efficient at sucking heat out of the combustion chamber that you have to bump C/R up a full point to get the same power that you'd get out of an iron head....so you'd need 11:1.
Top of the page Bottom of the page
Powerflite
Posted 2020-04-29 1:28 PM (#597515 - in reply to #576965)
Subject: Re: Old Hemi Parts



Expert 5K+

Posts: 6491
50001000100100100100252525
Location: So. California
Yes, but in terms of power, it also has much better designed ports & is much lighter so you would definitely win overall. But yeah, it's better to run even higher compression with an alloy head.
Top of the page Bottom of the page
51coronet
Posted 2020-04-29 2:32 PM (#597519 - in reply to #576965)
Subject: Re: Old Hemi Parts


Extreme Veteran

Posts: 326
10010010025
If I were any of these manufacturers I would get a stock uncut block and heads use the most common sized gasket (post that in my data), fit the pistons and calculate the real compression. Its a tiny investment, most people can afford an old stock hemi block and heads they are out there. This is just bad business practice on all of them. All they need is 1 good cylinder, 2 mains, 2 sealed valves, 1 journal, 1 combustion chamber and bearings.....just 1 good cylinder! easy enough to measure to make sure its stock or very close to it. start at BDC fill the cylinder with gel and rotate to TDC, there is the compressed volume . (you can modify a spark plug to capture all liquid that come out or come up with something). rotate back down so the leftover chamber liquid doesn't spill when you pull the head to measure how much is left over from the chamber. Obviously keep the cam out of the picture, no valve movement allowed! Pull the timing gear.

With the 2 you have a total and the chamber volume. Do the math. Easy peasy. Use a gel because straight liquid may get past the rings if its not a fresh build or using a total seal type top ring.

Edited by 51coronet 2020-04-29 2:36 PM
Top of the page Bottom of the page
Powerflite
Posted 2020-05-08 12:22 AM (#597930 - in reply to #576965)
Subject: Re: Old Hemi Parts



Expert 5K+

Posts: 6491
50001000100100100100252525
Location: So. California
I just checked out a new piston from Egge and compared it to my original '58 pistons. The top of the piston is about 0.004" shorter, but the valve reliefs are smaller too. My guess without modeling it out is, it is probably slightly higher compression than the original. but pretty close.
Top of the page Bottom of the page
Jump to page : 1
Now viewing page 1 [50 messages per page]
Jump to forum :
Search this forum
Printer friendly version
E-mail a link to this thread



(Delete all cookies set by this site)