Re: De-stroked Hemi possibilities?
[Re: LSP]
#2813635
08/26/20 05:07 PM
08/26/20 05:07 PM
|
Joined: Jan 2003
Posts: 7,495 Minnesota
Hemi_Joel
OP
master
|
OP
master
Joined: Jan 2003
Posts: 7,495
Minnesota
|
Interesting idea there, dad. I like it!
Lsp, the rules are in a book, nowhere online. Pre-74 iron production block and heads, block decking up to .125, 370 maximum cubes, no EFI, magneto or points ignition only, no welding on blocker heads unless it is for repairs. That's pretty much the rules for the engine.
[img]http://i.imgur.com/boeexFms.jpg[/img]31 Plymouth Coupe, 392 Hemi, T56 magnum RS23J71 RS27J77 RP23J71 RO23J71 WM21J8A I don't regret the things I've done. I only regret the things I didn't do. "Wise men talk because they have something to say; fools because they have to say something. ~ Plato"
|
|
|
Re: De-stroked Hemi possibilities?
[Re: Hemi_Joel]
#2813666
08/26/20 06:38 PM
08/26/20 06:38 PM
|
Joined: Aug 2003
Posts: 1,314 Charlotte, NC
LSP
pro stock
|
pro stock
Joined: Aug 2003
Posts: 1,314
Charlotte, NC
|
#230 400 block, add bolt in head bosses for upper head stud retention, aluminum main caps, hat sleeve to 4.185" (best ring packages at that bore), 3.350" 8 CW crank, 1.777" rod journals, GRP 6.400" aluminum rods, Gibtech LW COM balanced vertical gas ported billet pistons, .866" x 2.000" x .180" DLC pins, .6mm, .6mm, 2mm Riken ring set, Jesel cam drive, largest cam barrel that will fit, Jesel lifters, 290/275 @ .050 cam - lift depends on heads, Jesel rocker gear, largest pushrods that will fit, largest box/kickout pan that will fit, std volume oil pump, 2"/2.125"/2.250" headers/merge collector, offset heads down .030".
That's a good start, similar to what set the NHRA PRO STOCK speed record in 1981 at 165 mph, when they were real Hemis and small, but with a few updates that would help hp.
|
|
|
Re: De-stroked Hemi possibilities?
[Re: LSP]
#2813683
08/26/20 07:18 PM
08/26/20 07:18 PM
|
Joined: Jan 2003
Posts: 7,495 Minnesota
Hemi_Joel
OP
master
|
OP
master
Joined: Jan 2003
Posts: 7,495
Minnesota
|
#230 400 block, add bolt in head bosses for upper head stud retention, aluminum main caps, hat sleeve to 4.185" (best ring packages at that bore), 3.350" 8 CW crank, 1.777" rod journals, GRP 6.400" aluminum rods, Gibtech LW COM balanced vertical gas ported billet pistons, .866" x 2.000" x .180" DLC pins, .6mm, .6mm, 2mm Riken ring set, Jesel cam drive, largest cam barrel that will fit, Jesel lifters, 290/275 @ .050 cam - lift depends on heads, Jesel rocker gear, largest pushrods that will fit, largest box/kickout pan that will fit, std volume oil pump, 2"/2.125"/2.250" headers/merge collector, offset heads down .030".
That's a good start, similar to what set the NHRA PRO STOCK speed record in 1981 at 165 mph, when they were real Hemis and small, but with a few updates that would help hp. Awesome detail, thanks I like the idea of the bolt in head stud bosses. I never thought of that. A dry sump is okay if that would help
[img]http://i.imgur.com/boeexFms.jpg[/img]31 Plymouth Coupe, 392 Hemi, T56 magnum RS23J71 RS27J77 RP23J71 RO23J71 WM21J8A I don't regret the things I've done. I only regret the things I didn't do. "Wise men talk because they have something to say; fools because they have to say something. ~ Plato"
|
|
|
Re: De-stroked Hemi possibilities?
[Re: Hemi_Joel]
#2813834
08/27/20 07:16 AM
08/27/20 07:16 AM
|
Joined: Aug 2003
Posts: 1,314 Charlotte, NC
LSP
pro stock
|
pro stock
Joined: Aug 2003
Posts: 1,314
Charlotte, NC
|
#230 400 block, add bolt in head bosses for upper head stud retention, aluminum main caps, hat sleeve to 4.185" (best ring packages at that bore), 3.350" 8 CW crank, 1.777" rod journals, GRP 6.400" aluminum rods, Gibtech LW COM balanced vertical gas ported billet pistons, .866" x 2.000" x .180" DLC pins, .6mm, .6mm, 2mm Riken ring set, Jesel cam drive, largest cam barrel that will fit, Jesel lifters, 290/275 @ .050 cam - lift depends on heads, Jesel rocker gear, largest pushrods that will fit, largest box/kickout pan that will fit, std volume oil pump, 2"/2.125"/2.250" headers/merge collector, offset heads down .030".
That's a good start, similar to what set the NHRA PRO STOCK speed record in 1981 at 165 mph, when they were real Hemis and small, but with a few updates that would help hp. Awesome detail, thanks I like the idea of the bolt in head stud bosses. I never thought of that. A dry sump is okay if that would help Yes, used on BBC's in Pro Stock back in the day on blocks that didn't have the 4 extra upper head bolt bosses. Yes 4 compartment dry sump by all means with 20ish inches of vacuum.
|
|
|
Re: De-stroked Hemi possibilities?
[Re: LSP]
#2813862
08/27/20 09:26 AM
08/27/20 09:26 AM
|
Joined: Jan 2003
Posts: 7,495 Minnesota
Hemi_Joel
OP
master
|
OP
master
Joined: Jan 2003
Posts: 7,495
Minnesota
|
So the only reason that I can see to use the low deck block and give up the strength of the Hemi block is to improve the rod stroke/ ratio. Is it worth it?
Mechanical stack injection would probably be the hot ticket for induction.
How much horsepower will this thing make?
[img]http://i.imgur.com/boeexFms.jpg[/img]31 Plymouth Coupe, 392 Hemi, T56 magnum RS23J71 RS27J77 RP23J71 RO23J71 WM21J8A I don't regret the things I've done. I only regret the things I didn't do. "Wise men talk because they have something to say; fools because they have to say something. ~ Plato"
|
|
|
Re: De-stroked Hemi possibilities?
[Re: Hemi_Joel]
#2813874
08/27/20 09:50 AM
08/27/20 09:50 AM
|
Joined: Jan 2003
Posts: 10,038 MN
JERICOGTX
I Live Here
|
I Live Here
Joined: Jan 2003
Posts: 10,038
MN
|
The low deck block is stronger than a RB/HEMI block. Thicker main webs, Shorter/stiffer cylinder wall, shorter pushrods. Shorter piston. It all just adds up to a better package.
69 GTX
68 Road Runner
|
|
|
Re: De-stroked Hemi possibilities?
[Re: JERICOGTX]
#2813892
08/27/20 11:07 AM
08/27/20 11:07 AM
|
Joined: Jan 2003
Posts: 7,495 Minnesota
Hemi_Joel
OP
master
|
OP
master
Joined: Jan 2003
Posts: 7,495
Minnesota
|
The low deck block is stronger than a RB/HEMI block. Thicker main webs, Shorter/stiffer cylinder wall... What makes you think that? It's only two bolt main. The Hemi has better iron in it and I thought that the main webs were improved on the Hemi block.
[img]http://i.imgur.com/boeexFms.jpg[/img]31 Plymouth Coupe, 392 Hemi, T56 magnum RS23J71 RS27J77 RP23J71 RO23J71 WM21J8A I don't regret the things I've done. I only regret the things I didn't do. "Wise men talk because they have something to say; fools because they have to say something. ~ Plato"
|
|
|
Re: De-stroked Hemi possibilities?
[Re: JERICOGTX]
#2813896
08/27/20 11:15 AM
08/27/20 11:15 AM
|
Joined: Jan 2012
Posts: 2,653 Stuttgart, Arkansas
rickseeman
master
|
master
Joined: Jan 2012
Posts: 2,653
Stuttgart, Arkansas
|
The low deck block is stronger than a RB/HEMI block. Thicker main webs, Shorter/stiffer cylinder wall, shorter pushrods. Shorter piston. It all just adds up to a better package. I probably wouldn't phrase it exactly like that. Yes, most people feel the low deck block builds a better wedge for the reasons you stated. But that doesn't mean it make a better Hemi. The pushrod angle gets even worse if you make a Hemi out of a low deck. Thicker main webs don't make up for the cross bolted mains on the Hemi block. If he wants a Hemi, there are still some of the old Chrysler 366 cu in Hemi cranks out there. And new light weight rods and pistons are easily available.
2011 Drag Pak Challenger
|
|
|
Re: De-stroked Hemi possibilities?
[Re: rickseeman]
#2813901
08/27/20 11:25 AM
08/27/20 11:25 AM
|
Joined: May 2019
Posts: 713 Lake Villa Il
INTMD8
super stock
|
super stock
Joined: May 2019
Posts: 713
Lake Villa Il
|
So if you decked a hemi block to 10.6 and went with the 3.35 crank and 6.4 rods, would a 2.52 compression distance be a problem?
Maybe wouldn't be too heavy if a strutted piston?
69 Charger. 438ci Gen2 hemi. Flex fuel. Holley HP efi. 650rwhp @7250 510rwtq @5700
|
|
|
Re: De-stroked Hemi possibilities?
[Re: INTMD8]
#2813923
08/27/20 12:53 PM
08/27/20 12:53 PM
|
Joined: Jan 2003
Posts: 7,495 Minnesota
Hemi_Joel
OP
master
|
OP
master
Joined: Jan 2003
Posts: 7,495
Minnesota
|
So if you decked a hemi block to 10.6 and went with the 3.35 crank and 6.4 rods, would a 2.52 compression distance be a problem?
Maybe wouldn't be too heavy if a strutted piston? Id have to check with the piston guys.
[img]http://i.imgur.com/boeexFms.jpg[/img]31 Plymouth Coupe, 392 Hemi, T56 magnum RS23J71 RS27J77 RP23J71 RO23J71 WM21J8A I don't regret the things I've done. I only regret the things I didn't do. "Wise men talk because they have something to say; fools because they have to say something. ~ Plato"
|
|
|
|
|