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Re: De-stroked Hemi possibilities? [Re: Transman] #2812646
08/24/20 02:36 PM
08/24/20 02:36 PM
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MD-USA
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Dodgeguy101 Offline
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MD-USA
I'm pretty sure this question or something like it was asked awhile ago. Bob George answered and I believe he said they were a hand grenade waiting to go off. Could be wrong though on his answer, Im getting old and my wife tells me I cant remember anything. I would check in it further if it was me. Although I like the idea.

Re: De-stroked Hemi possibilities? [Re: Transman] #2812647
08/24/20 02:36 PM
08/24/20 02:36 PM
Joined: Jan 2003
Posts: 6,404
Minnesota
Hemi_Joel Offline OP
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Any intake, any carb(s), mechanical injection OK. No EFI. Points distributor or magneto only.

Transman, what is the rod journal dia on that 3.48 crank?


[img]http://i.imgur.com/boeexFms.jpg[/img]
31 Plymouth Coupe, 392 Hemi, T56 magnum
RS23J71
RS27J77
RP23J71
RO23J71
WM21J8A
Re: De-stroked Hemi possibilities? [Re: Hemi_Joel] #2812653
08/24/20 02:44 PM
08/24/20 02:44 PM
Joined: Nov 2009
Posts: 2,930
St. Paul , Mn.
tubtar Offline
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I'm not sure if you know Ron Flood...............North Branch , Mn. , but soon to be up Pine City way.
I believe he has a set of the B - RB to Hemi conversion heads , and Lord knows what else he has squirreled away , but he might be a good brain to pick for a project like this.
Cedar Machine.( 651 ) 674 - 8365
He is semi retired , but I think he would not be opposed to any project that was cool or interesting , and this sounds like both.

Re: De-stroked Hemi possibilities? [Re: tubtar] #2812663
08/24/20 03:03 PM
08/24/20 03:03 PM
Joined: Jan 2003
Posts: 6,404
Minnesota
Hemi_Joel Offline OP
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Unfortunately, I know Ron. Never again.


[img]http://i.imgur.com/boeexFms.jpg[/img]
31 Plymouth Coupe, 392 Hemi, T56 magnum
RS23J71
RS27J77
RP23J71
RO23J71
WM21J8A
Re: De-stroked Hemi possibilities? [Re: Hemi_Joel] #2812673
08/24/20 03:21 PM
08/24/20 03:21 PM
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Posts: 1,662
Michigan
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Transman Offline
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Michigan
Originally Posted by Hemi_Joel
Any intake, any carb(s), mechanical injection OK. No EFI. Points distributor or magneto only.

Transman, what is the rod journal dia on that 3.48 crank?


Standard B/RB - 2.375” with standard mains - 2.750”.
I also have a longer set of NASCAR rods at 7.06”.

Re: De-stroked Hemi possibilities? [Re: Hemi_Joel] #2812692
08/24/20 03:54 PM
08/24/20 03:54 PM
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Posts: 3,625
New York
polyspheric Offline
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I never learn.


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Re: De-stroked Hemi possibilities? [Re: polyspheric] #2812707
08/24/20 04:23 PM
08/24/20 04:23 PM
Joined: Jan 2003
Posts: 6,404
Minnesota
Hemi_Joel Offline OP
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That's good info to consider, Boff. What is the highest rod/stroke ratio that will still pull hard enuff on the intake to make big power?


[img]http://i.imgur.com/boeexFms.jpg[/img]
31 Plymouth Coupe, 392 Hemi, T56 magnum
RS23J71
RS27J77
RP23J71
RO23J71
WM21J8A
Re: De-stroked Hemi possibilities? [Re: Hemi_Joel] #2812713
08/24/20 04:35 PM
08/24/20 04:35 PM
Joined: Oct 2007
Posts: 3,625
New York
polyspheric Offline
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New York
Never mind, I'm sure it will be successful.


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Re: De-stroked Hemi possibilities? [Re: Hemi_Joel] #2812718
08/24/20 04:41 PM
08/24/20 04:41 PM
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New York
polyspheric Offline
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Good luck with your project


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Re: De-stroked Hemi possibilities? [Re: Hemi_Joel] #2812761
08/24/20 06:42 PM
08/24/20 06:42 PM
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Florida
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What about destroking/sleeving a 383/400 with Max-Wedge heads?
Custom/welded intakes allowed?

Last edited by Locomotion; 08/24/20 06:47 PM.
Re: De-stroked Hemi possibilities? [Re: Locomotion] #2812772
08/24/20 06:57 PM
08/24/20 06:57 PM
Joined: Jan 2003
Posts: 13,308
So. Burlington, Vt.
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fast68plymouth Offline
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So. Burlington, Vt.
In the end, I think a destroked hemi....... done without reinventing the wheel...... would likely make as much of more power than anything else you could come up with using factory castings from the competition.

A slightly stroked Boss 351 would also be a good option.

Re: De-stroked Hemi possibilities? [Re: fast68plymouth] #2812796
08/24/20 07:42 PM
08/24/20 07:42 PM
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Michigan
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Transman Offline
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All theory again. Empirical data. We tried a shorter rod versus the production long rod (6.960”) and the short rod lost power

In every situation. In the cas of both these engines it was solid tenth off the mark.

Stick with what works.

Re: De-stroked Hemi possibilities? [Re: Locomotion] #2812797
08/24/20 07:46 PM
08/24/20 07:46 PM
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MN
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JERICOGTX Offline
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Originally Posted by Locomotion
What about destroking/sleeving a 383/400 with Max-Wedge heads?
Custom/welded intakes allowed?


MaxWedge Joel just wouldn’t be right... I’d have to change my contact list in my phone then.


69 GTX 68 Road Runner
Re: De-stroked Hemi possibilities? [Re: JERICOGTX] #2812817
08/24/20 08:18 PM
08/24/20 08:18 PM
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Posts: 5,776
Melbourne , Australia
LA360 Offline
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Can you move the lifter bores around? The Wescott and Barton stuff all has the lifter bores moved, to straighten out the pushrod geometry. They have done for years.


Alan Jones
Re: De-stroked Hemi possibilities? [Re: Locomotion] #2812840
08/24/20 09:06 PM
08/24/20 09:06 PM
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Michigan
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Transman Offline
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Michigan
Originally Posted by Locomotion
What about destroking/sleeving a 383/400 with Max-Wedge heads?
Custom/welded intakes allowed?


We tried that before the de-stroked Hemi. 361 block. 348 cubic inches, port matched maxwedge heads, single 4 bbl. Ran it way past 8500.
4 speed. I think you would be hard pressed to get close to Hemi power even with state of the art raised port maxies.

Valve train would be easier to sort out on a wedge.

Last edited by Transman; 08/24/20 10:08 PM.
Re: De-stroked Hemi possibilities? [Re: LA360] #2812872
08/24/20 10:07 PM
08/24/20 10:07 PM
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Posts: 6,404
Minnesota
Hemi_Joel Offline OP
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Originally Posted by LA360
Can you move the lifter bores around? The Wescott and Barton stuff all has the lifter bores moved, to straighten out the pushrod geometry. They have done for years.


Yes that would be legal. Big can core/can bearings ok too


[img]http://i.imgur.com/boeexFms.jpg[/img]
31 Plymouth Coupe, 392 Hemi, T56 magnum
RS23J71
RS27J77
RP23J71
RO23J71
WM21J8A
Re: De-stroked Hemi possibilities? [Re: JERICOGTX] #2812875
08/24/20 10:09 PM
08/24/20 10:09 PM
Joined: Jan 2003
Posts: 6,404
Minnesota
Hemi_Joel Offline OP
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Originally Posted by JERICOGTX
Originally Posted by Locomotion
What about destroking/sleeving a 383/400 with Max-Wedge heads?
Custom/welded intakes allowed?


MaxWedge Joel just wouldn’t be right... I’d have to change my contact list in my phone then.


You know me well, Jeff! Hemi Joel without a Hemi is like JericoGTX with a powerglide. drive


[img]http://i.imgur.com/boeexFms.jpg[/img]
31 Plymouth Coupe, 392 Hemi, T56 magnum
RS23J71
RS27J77
RP23J71
RO23J71
WM21J8A
Re: De-stroked Hemi possibilities? [Re: Hemi_Joel] #2813013
08/25/20 10:01 AM
08/25/20 10:01 AM
Joined: Oct 2008
Posts: 1,042
East Coast
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A/MP Offline
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East Coast
I had a 396 hemi a long time ago in my MP car. It never made the power that I thought, at least on my budget. I was better off with just running the weight to match the cubes.

Re: De-stroked Hemi possibilities? [Re: Hemi_Joel] #2813085
08/25/20 01:00 PM
08/25/20 01:00 PM
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Posts: 228
Northeast Indiana
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73DAD Offline
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Northeast Indiana
Here's how you do it

You start with a 400 block because you want the B-engine mains. Make two 3/4" thick deck plates to adapt the Hemi heads to the wedge block while simultaneously bringing the deck up to standard RB height. You want that extra deck plate thickness so you have a better angle at grinding clearance for the pushrod in the block valley without hitting water. You also need the extra thickness for addressing the inner head stud mis-match, & oil drainback.

Bore the 400 block & the deck plates to accept sleeves pressed through BOTH the plates & block to get the bore down to 4.25". The cylinder walls will now be super thick & tied together nicely.

Next, take a B-engine crank & destroke/offset grind it down to big block Chevy size on the rods, taking it from 3.375" down to 3.21". This will yield a 364" engine with room to bore/hone during rebuilds.

With a 3.21" stroke, 7.1" rods, & a 10.725" total deck, the pistons can be a convenient stock or near-stock height, but will need a big-*** dome to make any compression. The typical 12.5:1 race hemi pistons might be a cheap route if you can come up with a 7.1" rod to handle the pin end at a price to make them worth it.

There you go, a wedge based 364" Gen II solution that might actually be cheaper than building the real deal. Go forth & go fast.

Re: De-stroked Hemi possibilities? [Re: 73DAD] #2813106
08/25/20 02:01 PM
08/25/20 02:01 PM
Joined: Dec 2005
Posts: 1,445
Shelby mi.
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JAKE68 Offline
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Shelby mi.
THE BIGGEST PROBLEM WITH THAT KIND OF RPM IS STABLIZING THE VALVE TRAIN. RAY BARTON AND JESEL ARE NOW GETTING A HOLD OF IT AT 10500. ANYTING MORE THAN THAT I DONT KNOW.


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