Magnum shortblock capability.

[B3422w5]

This guy is pushing a 360 magnum block to 771 HP. But I don’t know for how long. At the 2018 engine masters challenge he only made 737 HP. Which is still damn empressive to me.

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Know these guys really well. In fact they are gonna do some work for me over the winter. Jack says a production magnum block is much stronger than an LA block. Harder, more meat for maincaps.
Btw, that victor motor you posted, the block is tall filled.
That motor makes over 800 ponies if he spins it over 8k. Contest limited it to 7500 per the rules.
It made the 737 with muffs on it in 95 degree heat, btw.
Not too shabby for an under 12 to 1 stock stroke 360

 

[rumblefish360]

Who’s mill is it?

 

[mopar65]

Know these guys really well. In fact they are gonna do some work for me over the winter. Jack says a production magnum block is much stronger than an LA block. Harder, more meat for maincaps.
Btw, that victor motor you posted, the block is tall filled.
That motor makes over 800 ponies if he spins it over 8k. Contest limited it to 7500 per the rules.
It made the 737 with muffs on it in 95 degree heat, btw.
Not too shabby for an under 12 to 1 stock stroke 360

Thanks for the info. I am really intrested in what it took to put LA heads on a 360 magnum block. I would love to have a engine like that for my 96 Dakota race truck.

 

[rumblefish360]

Thanks for the info. I am really intrested in what it took to put LA heads on a 360 magnum block. I would love to have a engine like that for my 96 Dakota race truck.

I seen one fella drill the block in the same spot as the LA oiling hole is about, 4 inches down and tap into that off the main oil gallery.

 

[pittsburghracer]

Ok. Lets try this instead.
Will a bone stock Magnum shortblock with just some forged pistons, a balancejob and an oilpan that fits in a car handle say 7500rpm and 500HP?
If not what would be the point of failure?

If the isue would be rods,pretend that we swap those aswell for someting stronger.


Lets focus on if the cranks and oilingsystems can handle it,pretend its naturaly aspirated engine with a solid roller so we can ignore the valvetrain part of the question for now. No strokers or anything like that. Just stock cranks and oilingsystems.

And im not talking about 7500rpm wide open for hours,more of a street/strip thing
This is partialy out of quriosity but there is some serious thinking behind this.

Why do you guys insist on shifting these engines at 7500 rpm? I shift my 422 at 7000 and it runs 9.40’s. My son shifts his stock crank 360 at 6800 and it runs 10.30’s. Why beat the piss out of them

 

[rumblefish360]

I think the number 7500 was just pulled out of the air as an extreme shift point. Not necessarily meaning that he’s going to go there.

 

[stixx]

Stock stroke 360 on the dyno

Here's another build that should fit the bill...

 

[B3422w5]

Thanks for the info. I am really intrested in what it took to put LA heads on a 360 magnum block. I would love to have a engine like that for my 96 Dakota race truck.

The new trick flow heads will work on either Magnum or LA blocks, along with the new intake

 

[1Fast340]

Why do you guys insist on shifting these engines at 7500 rpm? I shift my 422 at 7000 and it runs 9.40’s. My son shifts his stock crank 360 at 6800 and it runs 10.30’s. Why beat the piss out of them

Just trying to figure out where the limitations realy are on a subject that i find intresting. LA engines are getting harder to find and Magnums are still very available,and figure these things could be built oldschool as in add cam and compression to make up for lack of headflow and cubes,remember there was a time when strokercranks where just as rare as good heads and how things where built back then.

But since you ask i would like to start with that i believe that your 4" stroker is probably beating up the block harder at 7000rpm than a 3.31 crank engine will do at 7500rpm.
Would also like to add that i believe that if you took the topend and camshaft of your sons 360 and put it on a 318 it would probably be shifted somewhere around7200rpm due to how these smaller engines extend their productive rpmrange uppwards and how they tend to not nose over as hard as bigger engines does,unless valveshrouding gets realy bad so its not all irrelevant realy.
I respect your knowledge and both your car and your sons are very impressive but i hope you can think alitle outside the box here.

I think the number 7500 was just pulled out of the air as an extreme shift point. Not necessarily meaning that he’s going to go there.

You are correct as you often are!
I may take one of them things there at some point mostly trying to figure out what the real limitations realy are at present before i comit on a direction since i have not fully descided on where my next enginebuild is going and have no rush to get there but i have sort of got the impression that Magnums can take alitle more than the older LA stuff.

Stock stroke 360 on the dyno

Here's another build that should fit the bill...

Thats some usefull information,thank you!

 

[rumblefish360]

@1Fast340 I would say it would take a big cam to be looking at a 7500 and plus shift point along with a set of big heads. That combo would move up the rpm peak and shift point a good bit making the engine a strip only deal. (Something most of hot street strip guys and engine builders get.)

Are you thinking of going down this route?

 

[pittsburghracer]

Just trying to figure out where the limitations realy are on a subject that i find intresting. LA engines are getting harder to find and Magnums are still very available,and figure these things could be built oldschool as in add cam and compression to make up for lack of headflow and cubes,remember there was a time when strokercranks where just as rare as good heads and how things where built back then.

But since you ask i would like to start with that i believe that your 4" stroker is probably beating up the block harder at 7000rpm than a 3.31 crank engine will do at 7500rpm.
Would also like to add that i believe that if you took the topend and camshaft of your sons 360 and put it on a 318 it would probably be shifted somewhere around7200rpm due to how these smaller engines extend their productive rpmrange uppwards and how they tend to not nose over as hard as bigger engines does,unless valveshrouding gets realy bad so its not all irrelevant realy.
I respect your knowledge and both your car and your sons are very impressive but i hope you can think alitle outside the box here.





You are correct as you often are!
I may take one of them things there at some point mostly trying to figure out what the real limitations realy are at present before i comit on a direction since i have not fully descided on where my next enginebuild is going and have no rush to get there but i have sort of got the impression that Magnums can take alitle more than the older LA stuff.



Thats some usefull information,thank you!

I was at a race at Keystone several years ago and was introduced to one of the guys that worked on the Ritter small block mopar. We sipped a few adult drinks together around the campfire a couple of nights bs'ing of coarse about Mopars. I enjoyed the heck out of listening to him and one of his big gripes was that most, not all but most Mopar guys insisted on building "stroker smallblocks." He being a stock or super stock racer knew what the smaller engines were capable of. That kinda etched a mark in my brain so I have a .040 360 block on a spare stand that I bought a couple of years ago. I tried to buy a stock stroke chevy journal crank as the one that came with it was a cast 360 crank cut down to chevy size. That kinda scares me because I want to push this build HARD. I talked to Molnar so far and checked out Ohio crank with zero luck. Seeing how easily my Sons Duster at 3200 pounds runs 10.30's with a 600 lift roller has me thinking 9.50's is doable at 2860 in my Duster without beating on it to hard.

 

[RustyRatRod]

It will last until it splits in half.

 

[nm9stheham]

I have a .040 360 block on a spare stand that I bought a couple of years ago. I tried to buy a stock stroke chevy journal crank as the one that came with it was a cast 360 crank cut down to chevy size. That kinda scares me because I want to push this build HARD.

If I understand this right..... So will they not cut a stock journaled Mopar crank down to SBC size? Is this 2.100 or 2.000"? I've just been going through some strength computations with cutting down the journals today on another project, so this caught my eye.

 

[pittsburghracer]

If I understand this right..... So will they not cut a stock journaled Mopar crank down to SBC size? Is this 2.100 or 2.000"? I've just been going through some strength computations with cutting down the journals today on another project, so this caught my eye.

I was looking for 2.100 since I have Crower rods in that size. I bought the rotating assembly then he offered up the block so I made another road trip for it. Its a poured block with bronze lifter bores and lots of oiling mods. I just had my 4.500 stroke mopar journal Calias crank cut down to chevy size so I know its doable but it wasn't cheap plus this was a good crank to start with.

 

[nm9stheham]

I am curious as to why cutting down 2.125 to 2.100 would cost much at all? Why not just cut down a forged unit? Or did they just not think their forged cranks would handle 700 HP? (That is a lot of 'juice' through a 360 LOL)

For a regular sold journal crank, the strength loss going to 2.100" is pretty trivial, at least for the more 'static' type of stresses on the crank like journal bending and twist. But, I'll guess you'll be turning some really high RPM's for this goal....and that gets into different 'dynamic' problems that I can't start to work. But I very seriously doubt that losing .025" in the crankpin will make any difference there; those dynamic problems are addressed more in the overall crank design.

FWIW as a side note..... the thing I 'discovered' today buried in the materials numbers was that the fatigue strength goes up several times higher for steel vs cast iron. So it is under that repetitive hammering from the pistons and rods where the forged holds up.

 

[1Fast340]

@1Fast340 I would say it would take a big cam to be looking at a 7500 and plus shift point along with a set of big heads. That combo would move up the rpm peak and shift point a good bit making the engine a strip only deal. (Something most of hot street strip guys and engine builders get.)

Are you thinking of going down this route?

Not looking at going quite that far in the first version of where im going if im going Magnum,but if i go for a Magnum there is quite a big chance i will end up pushing things that far later on,also depending on if i end up with a 318 or 360,i know the 360version is the obvious option but im alitle retarded from time to time and might just decide that i want to go totaly against comon sence again.
I did put that number up there to see if anyone knew what would fail if anything at that point,certainly not a dealbreaker by any means but good to know how far things can be pushed,considering how people are going overkill on everything just buying the latest and greatest and forgetting the good old hotroding spirit of doing more with less and doing so while not following the book so to speak.
Its quite funny talking to friends with chevys and when oilingsystems are brought up in conversations they get all confused when you try to explain to them what moparguys says needs to be done for our fine smallblocks to survive at higher rpm.

I was at a race at Keystone several years ago and was introduced to one of the guys that worked on the Ritter small block mopar. We sipped a few adult drinks together around the campfire a couple of nights bs'ing of coarse about Mopars. I enjoyed the heck out of listening to him and one of his big gripes was that most, not all but most Mopar guys insisted on building "stroker smallblocks." He being a stock or super stock racer knew what the smaller engines were capable of. That kinda etched a mark in my brain so I have a .040 360 block on a spare stand that I bought a couple of years ago. I tried to buy a stock stroke chevy journal crank as the one that came with it was a cast 360 crank cut down to chevy size. That kinda scares me because I want to push this build HARD. I talked to Molnar so far and checked out Ohio crank with zero luck. Seeing how easily my Sons Duster at 3200 pounds runs 10.30's with a 600 lift roller has me thinking 9.50's is doable at 2860 in my Duster without beating on it to hard.

That must have been an intresting conversation for sure,its amazing to listen to people who are realy sharp and has been there,done that and probably lost the t-shirt in the process
I do understand why people are running strokers,i just think there is alot of performance to be found at stock stroke aswell and less hard on the block even thought the oilingsystem and valvetrain takes a beating,just a mather of adding gear to make up for the extra rpm it takes to make the power and thats where you get your torque back.

It will last until it splits in half.

Nice of you to bring up Ford products in this thread but i think they call their bread and butter engines "Windsor" here in moparland we have Magnums and those have stronger blocks and i thought they where more suspect to have lubractionfailures over Fords blockfailures.

 

[MopaR&D]

Factory short block 5.9, EQ Heads, AirGap, camswap and good carb (and headers) make for an easy low to mid 12 second Abody. There are a few of us that have done it.
I love my junkyard 5.9 magnum. It is turbo'd now and I've been running it at around 6psi for a couple of years which I believe puts it close to 475HP. I recently turned up the boost to 10-11psi and it's absolutely violent in this little Abody. Probably closer to 550hp at that pressure. Not sure how long it will last but I keep it under 5500rpms and watch my tune carefully.

Good to know, I'm putting together a stock Mag short block with ported Eddy heads and head studs, probably throw 6-10 lbs at it at some point...

 

[RustyRatRod]

Nice of you to bring up Ford products in this thread but i think they call their bread and butter engines "Windsor" here in moparland we have Magnums and those have stronger blocks and i thought they where more suspect to have lubractionfailures over Fords blockfailures.

LOL

What I meant was, everyone wants to know the power level this will take, what that will take. That's no clear cut answer. Yours may take 500HP. Someone else's may take 650. The rest of the question is always left out. How much will it take "before somethin bad happens", so I always say "until it splits apart" or "until somethin bad happens", because you simply never know there are so many variables.

Where your assertion I brought Ford into this came from, I haven't a clue, but if it makes you feel better.........I'll tell you the story of a childhood friend of mine named Mike Mason. Those that have me on Facebook can at least verify he is on my friend list.

He had a 89 Mustang I believe it was years ago.......had like 93 front and rear facias on it. It was a "oddball" cubic inch displacement, because he got the wrong rotating assembly but built it anyway. A 382 or some such if memory serves. Stock 351 block based engine.

He never got on a chassis dyno that I know of, but that car used to run 8.40s all night long at The Silver Dollar Raceway in Reynolds, Georgia. He even used to get it out to the local Brewsters ice cream store in North Macon. He even kept the 8.8 rear axle under it until of course the inevitable happened and then he went with a Dana. I lost track of him sometime around then, but now he comes in the store almost every Saturday with a mutual friend, Mark Byrd, so I can ask Mike what became of the car and engine. I think he sold it, but it may still be around.

Mark, (also on Facebook) has a 1500 plus HP Chevy 1500 5.3 "street truck" with one large by huge turbo under the hood. Mark's race car is called "RIP"

Here is RIP makin a pass.



They are finally gettin that car worked out as evidenced by it "gittin with it" in this video. All I know is the car is "between this HP level and that" since it's a money car and they won't say. The turbo on that car is 2 or 3 times big as my head. Search more on youtube, he does a kinda walk around on it. It's a very professional car.

Will that block eventually fail? Probably, but not before it makes them a lot of money, I bet. And we've been talkin about 650 chump change here? lol

 

[1Fast340]

LOL

What I meant was, everyone wants to know the power level this will take, what that will take. That's no clear cut answer. Yours may take 500HP. Someone else's may take 650. The rest of the question is always left out. How much will it take "before somethin bad happens", so I always say "until it splits apart" or "until somethin bad happens", because you simply never know there are so many variables.

Where your assertion I brought Ford into this came from, I haven't a clue, but if it makes you feel better.........I'll tell you the story of a childhood friend of mine named Mike Mason. Those that have me on Facebook can at least verify he is on my friend list.

He had a 89 Mustang I believe it was years ago.......had like 93 front and rear facias on it. It was a "oddball" cubic inch displacement, because he got the wrong rotating assembly but built it anyway. A 382 or some such if memory serves. Stock 351 block based engine.

He never got on a chassis dyno that I know of, but that car used to run 8.40s all night long at The Silver Dollar Raceway in Reynolds, Georgia. He even used to get it out to the local Brewsters ice cream store in North Macon. He even kept the 8.8 rear axle under it until of course the inevitable happened and then he went with a Dana. I lost track of him sometime around then, but now he comes in the store almost every Saturday with a mutual friend, Mark Byrd, so I can ask Mike what became of the car and engine. I think he sold it, but it may still be around.

Mark, (also on Facebook) has a 1500 plus HP Chevy 1500 5.3 "street truck" with one large by huge turbo under the hood. Mark's race car is called "RIP"

Here is RIP makin a pass.



They are finally gettin that car worked out as evidenced by it "gittin with it" in this video. All I know is the car is "between this HP level and that" since it's a money car and they won't say. The turbo on that car is 2 or 3 times big as my head. Search more on youtube, he does a kinda walk around on it. It's a very professional car.

Will that block eventually fail? Probably, but not before it makes them a lot of money, I bet. And we've been talkin about 650 chump change here? lol

Yeah i know but there are always some kind of general level that is somewhat safe to stay under even thought it may not be guaranteed that it will last, i know people are alitel cautios about giving this kind of advice for good reason,but i feel safe in saying that im aware that sometimes **** blow up far below what the parts should be able to take and sometimes they survive a bunch more than they should.
Just trying to bring back some good old hotroding into a hobby where alot of people seems to have got stuck in a mode of buying all the latest and greatest and doing things that are certainly not stupid but may be overly cautios so to speak.

The Ford reference comes from 302 Ford smallblocks being known to literarly split in half,blocks cracking straight thru the mains and camtunnel at some lever of punnishment that seems to be lower than what mopar smallblocks can handle.

That Camaro hauls it! nice!




From what little research i have done on Magnums they seem to handle alitle more punishment than LA blocks and comes with a few nice features such as one piece pan-gaskets, supposedly alitle taller lifterbores wich should be a nice feature,multirib belt for accessorys, better heads than LA motors(except that they seem to crack often) and that bolt angle on intakemanifolds should be nice,also found that they probably have the best intake manifold (indy)for big power available for standard heads.
It seems as if Magnum heads where a popular conversion on LA shortblocks 10 years or so ago then everyone went for edelbrocks and then later EQ or RHS heads but the stockish shortblocks dont seems to have many friends at all.

 

[pittsburghracer]

The bottom line is how fast do you want to go? 9's in a 2800-3200 pound car is VERY doable in either a LA or magnum engine block. I get tired of hearing how much better the magnum block is out of guys that are going slow.

 

[1Fast340]

The bottom line is how fast do you want to go? 9's in a 2800-3200 pound car is VERY doable in either a LA or magnum engine block. I get tired of hearing how much better the magnum block is out of guys that are going slow.

Im not going to go into the 9s on a stock crank,stock oilingsystem in a 3200pound streetcar on regular pumpfuel anyway so i think we can drop that thought. Just trying to figure out how far things can reasonably be pushed before i need to start caring about that part,i realy have no dessire to overbuild things or put more effort into this than needs to be done,yes i know for sure that alot of times its better to do everything at once and be done with it but thats not the plan here and i doubt my next shorthblock will ever be in the car long enough to be worth overdoing.

I dont think the magnumblocks are the best thing since sliced bread but i doubt they are any worse than any LA block i would rather beleive that they might just be better stock considering how machining tolerances has improved over time.

 

[RustyRatRod]

The Windsor Ford block I will somewhat defend. All I will say is........look how small it is. LOL

Yeah i know but there are always some kind of general level that is somewhat safe to stay under even thought it may not be guaranteed that it will last, i know people are alitel cautios about giving this kind of advice for good reason,but i feel safe in saying that im aware that sometimes **** blow up far below what the parts should be able to take and sometimes they survive a bunch more than they should.
Just trying to bring back some good old hotroding into a hobby where alot of people seems to have got stuck in a mode of buying all the latest and greatest and doing things that are certainly not stupid but may be overly cautios so to speak.

The Ford reference comes from 302 Ford smallblocks being known to literarly split in half,blocks cracking straight thru the mains and camtunnel at some lever of punnishment that seems to be lower than what mopar smallblocks can handle.

That Camaro hauls it! nice!




From what little research i have done on Magnums they seem to handle alitle more punishment than LA blocks and comes with a few nice features such as one piece pan-gaskets, supposedly alitle taller lifterbores wich should be a nice feature,multirib belt for accessorys, better heads than LA motors(except that they seem to crack often) and that bolt angle on intakemanifolds should be nice,also found that they probably have the best intake manifold (indy)for big power available for standard heads.
It seems as if Magnum heads where a popular conversion on LA shortblocks 10 years or so ago then everyone went for edelbrocks and then later EQ or RHS heads but the stockish shortblocks dont seems to have many friends at all.

 

[MopaR&D]

Im not going to go into the 9s on a stock crank,stock oilingsystem in a 3200pound streetcar on regular pumpfuel anyway so i think we can drop that thought. Just trying to figure out how far things can reasonably be pushed before i need to start caring about that part,i realy have no dessire to overbuild things or put more effort into this than needs to be done,yes i know for sure that alot of times its better to do everything at once and be done with it but thats not the plan here and i doubt my next shorthblock will ever be in the car long enough to be worth overdoing.

I dont think the magnumblocks are the best thing since sliced bread but i doubt they are any worse than any LA block i would rather beleive that they might just be better stock considering how machining tolerances has improved over time.

I haven't had the chance to "blueprint" a Magnum block but just from looking at mine the first notable aspect is how TIGHT the piston-to-bore clearances are. Also less casting flash inside the block, cooling passages are cleaner and seem a tad more open (I do know the core plug locations were moved from LA to Magnum). I'm willing to bet the factory decks are much closer to square than LA engines. Also keep in mind most of the Magnum blocks were cast in Mexico, mine has "Hecho En Mexico" cast into the side... might be BS but I've heard Mexican manufacturing and materials are pretty dang good (anyone heard of the Mexican 5.0 Fords?). All the G3 Hemis are made in Mexico btw.

 

[rumblefish360]

Mexican manufacturing has come a long way.

 

[B3422w5]

The bottom line is how fast do you want to go? 9's in a 2800-3200 pound car is VERY doable in either a LA or magnum engine block. I get tired of hearing how much better the magnum block is out of guys that are going slow.

I heard the magnum block is stronger from a local machine shop owner/ engine builder who has forgotten more than i know.
Is it OK if i repeat his info. Its the guy who built the stock stroke 360 with victor heads that made 771