Is it worth the $ to build a 5.9 Magnum (or LA 360) without making it a stroker?

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MRGTX

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Just tossing this one around this morning...and input, opinions, experiences are very welcome.

So I think most of us are familiar with the 4" crank stroker build for these motors and it seems like a very easy way to make a 450+hp small block.

The downside to a stroker motor is that the longer travel of the pistons means more losses due to friction and the increased force required to accelerate the pistons through much higher piston speeds. The effect can be a motor that's less happy to rev or one that starts to hit the physical limitations of the rods sooner, etc. Almost without exception, the tradeoff is well-worth it as the power gains are significant, especially if you're taking your car to the drag strip.

One part of driving that I have grown to love is a high-revving engine with a broad power band even if that comes at the sacrifice of the peak power. Low end grunt never gets old...but a motor that feels good on the far-right end of the tachometer is fun on a whole new level. For anyone who hasn't driven one yet, the sounds and sensations of good breathing V8 turning 7,000+ RPM is an experience that any gearhead needs to experience as soon as possible and as often as possible.

Is anything like this even attainable with our small blocks or would we need to look and Chevy LSx swaps to even consider this? :D

Currently, my stock Magnum is all done by about 4200. It never sounds particularly good, it never feels particularly good. There's no doubt that this motor would be much more at home under the hood of a Ram or a Dakota. It's basically the exact opposite of the V8 experience that I prefer.

How far can you take a Magnum 5.9 or an LA 360 with the stock crank? Is it worth the effort to do a build this way? How do these motors run?

Is it correct to say that our engines are limited by the valve-lift limitations of the head designs that we are stuck with?

Any thoughts are appreciated.
 
Just tossing this one around this morning...and input, opinions, experiences are very welcome.

So I think most of us are familiar with the 4" crank stroker build for these motors and it seems like a very easy way to make a 450+hp small block.

The downside to a stroker motor is that the longer travel of the pistons means more losses due to friction and the increased force required to accelerate the pistons through much higher piston speeds. The effect can be a motor that's less happy to rev or one that starts to hit the physical limitations of the rods sooner, etc. Almost without exception, the tradeoff is well-worth it as the power gains are significant, especially if you're taking your car to the drag strip.

One part of driving that I have grown to love is a high-revving engine with a broad power band even if that comes at the sacrifice of the peak power. Low end grunt never gets old...but a motor that feels good on the far-right end of the tachometer is fun on a whole new level. For anyone who hasn't driven one yet, the sounds and sensations of good breathing V8 turning 7,000+ RPM is an experience that any gearhead needs to experience as soon as possible and as often as possible.

Is anything like this even attainable with our small blocks or would we need to look and Chevy LSx swaps to even consider this? :D

Currently, my stock Magnum is all done by about 4200. It never sounds particularly good, it never feels particularly good. There's no doubt that this motor would be much more at home under the hood of a Ram or a Dakota. It's basically the exact opposite of the V8 experience that I prefer.

How far can you take a Magnum 5.9 or an LA 360 with the stock crank? Is it worth the effort to do a build this way? How do these motors run?

Is it correct to say that our engines are limited by the valve-lift limitations of the head designs that we are stuck with?

Any thoughts are appreciated.

The everyman's 360 LA Eddy headed engine dyno tested

360 Street/Strip Bruiser-Dyno results

Cheepy Three-Sixty build

New life for an old 340 (stock stroke)

Just browse the forum or use the search function... MANY threads on here about builds that could fit the bill. The posted above are three 360's and one 340,
and that is just from one member here... Brian from IMM also posted some IIRC. There is TONS of food for thought on this forum!
 
If you want 7000 rpm very often with an LA or Magnum based engine, then get a good forged crank. Once you are buying a new crank, why not go bigger.
If 400-450 horsepower is the goal, especially at 6500 rpm and less, factory cast cranks can live a long happy life.
The friction and drag thoughts are not an issue with a 4" stroke Mopar small block. Getting it to rev quick has more to do with the combination of parts to make it breath, especially camshaft events.

Build Your Own 455HP Pump-Gas Magnum V8 For Around $4,000! - Hot Rod Network
 
I bought a cast 4" crank(scat), I-beam(scat), icon forged pistons, total seal rings kit from Jegs for my L A base small block. The machine shop internally balanced it. (4-5 years ago) 7k all day.. I have but obviously I don't because that just wear's out the motor unnecessarily. My cam choice and there's been a couple has had dramatic effects on performance characteristics. With the light internals it rev's like a 2 stroke... LOL my-2..
 
This is my advice, and I'm not being sarcastic. If your 360 magnum is "done" at 4200 rpm's, do NOT spend money on a stroker. Why? All my factory stock magnums I've owned pulled real good to 4800 rpm's in Durangos or pickups. If your magnum is at about 60% health, then work on learning to tune or diagnose problems.

I remember an unhealthy 340 (the fixings, cam, headers, 4bbl) in a Volare, and the guy had 4.11 gears, ya know the story. He was running 14.40's and said his problem was he needed "more gears". LOL... :D I just nodded in agreement. LOL

Question, how fast you wanna go? Lots of stock stroke 360's in the 10's
 
A good valve job and mild porting on the stock heads will show very good gains for little investment. Also like has been said, the camshaft is a big limiting factor. All 5.2/5.9 cams were designed for trucks and heavy suvs. I have had oregon cams regrind a few for me and love them. Remember an engine is just an air pump, the better it can breathe the better it will run.
 
Stock rods and stock crank can't take 7k rpm for very long . Remember , a small block has only 4 bolts per cylinder and 2 bolt mains . this is a BIG deal when high revving engines are wanted . A lot of engines can rev to 7k but they are not doing anything but making noise . JMO
 
E45DA925-2AD8-42C7-BD99-01A488228EA4.jpeg
I’ll take a stock 360 cast crank over a aftermarket cast crank any day of the week. .030 over 360, .600 lift roller cam, Edelbrock heads, Victor340 intake. 6.54 in the 1/8 mile, low 10’s in the 1/4 @ 3200 pounds
 
Always wanted to build a stock stroke 360 with forged internals, W2 heads and a solid roller.


I tried to get a stock stroke 360 crank with a Chevy journal but couldn’t find one. You would love that combo with a W2 Head build as it would easily run 9’s in an A body.
 
I tried to get a stock stroke 360 crank with a Chevy journal but couldn’t find one. You would love that combo with a W2 Head build as it would easily run 9’s in an A body.
I have one of those with 340 journal size, it says mopar on it but I believe Scat made them. In the future I will be combining it with an R3 block and 48 degree w2 heads. That build is several years away though. It seems to me that for a race application people are trending away from the 4" arm in favor of the 3.58, although I have no proof to back that statement.
 
I tried to get a stock stroke 360 crank with a Chevy journal but couldn’t find one. You would love that combo with a W2 Head build as it would easily run 9’s in an A body.
Here is the part number of the 340 main version.
s-l400.jpg
 
At 50.00 a pop for 360 shortblocks that's what I have on stock, except my 340 based R3 block. That one will stay a stroker.
Yep, I'm totally with you there. The abundance and cost of the 360's make them very very attractive. Additionally, the extra torque from those 20 cubes is a free bonus. Out of curiosity, you have some hard hitting 360's that obviously turn serious rpm, have you had any issues with high bearing speed from the large 360 journals?
 
Yep, I'm totally with you there. The abundance and cost of the 360's make them very very attractive. Additionally, the extra torque from those 20 cubes is a free bonus. Out of curiosity, you have some hard hitting 360's that obviously turn serious rpm, have you had any issues with high bearing speed from the large 360 journals?

My sons 360 engine that run 10.20-10.30's is shifted at or under 6800 RPM so we don't consider that real high. My 422 that runs 9.42 is shifted at 7000 rpm. Matts engine started making a noise right after another 6.54 pass so we parked it in October and haven't torn into it yet. This engine was orginally build with a Racer Brown 520 lift solid lifter cam and he wanted a 600 roller so I with the short block already together I didn't tube the block. BIG MISTAKE as we had oil gushing past the 3 different styles of roller lifters I tried. I finally block the oil off to the one side and oil pressure was good but I knew we were still wasting oil badly one the one side. I'm betting we slightly hurt a bearing but like I said he caught it and ran my car for the rest of the weekend. I will NEVER build another 360 without tubing the block and his will be tubed real soon.
 
My sons 360 engine that run 10.20-10.30's is shifted at or under 6800 RPM so we don't consider that real high. My 422 that runs 9.42 is shifted at 7000 rpm. Matts engine started making a noise right after another 6.54 pass so we parked it in October and haven't torn into it yet. This engine was orginally build with a Racer Brown 520 lift solid lifter cam and he wanted a 600 roller so I with the short block already together I didn't tube the block. BIG MISTAKE as we had oil gushing past the 3 different styles of roller lifters I tried. I finally block the oil off to the one side and oil pressure was good but I knew we were still wasting oil badly one the one side. I'm betting we slightly hurt a bearing but like I said he caught it and ran my car for the rest of the weekend. I will NEVER build another 360 without tubing the block and his will be tubed real soon.
What is tubing the block and what does it do?
I am an amature here, so any info will help me follow along...........
 
My sons 360 engine that run 10.20-10.30's is shifted at or under 6800 RPM so we don't consider that real high. My 422 that runs 9.42 is shifted at 7000 rpm. Matts engine started making a noise right after another 6.54 pass so we parked it in October and haven't torn into it yet. This engine was orginally build with a Racer Brown 520 lift solid lifter cam and he wanted a 600 roller so I with the short block already together I didn't tube the block. BIG MISTAKE as we had oil gushing past the 3 different styles of roller lifters I tried. I finally block the oil off to the one side and oil pressure was good but I knew we were still wasting oil badly one the one side. I'm betting we slightly hurt a bearing but like I said he caught it and ran my car for the rest of the weekend. I will NEVER build another 360 without tubing the block and his will be tubed real soon.
How about the late models 360 LA with roller cams, does anyone know how much lift that block will take before bleeding oil around the lifters?
Cant seem to find any info about that.
 
What is tubing the block and what does it do?
I am an amature here, so any info will help me follow along...........


I was going to take a couple of quick pictures of one of my old tubed blocks that is headed for the scrap pile but really you can’t see much. We had a couple of real good posts on this subject several months ago that you should be able to find. It involves drilling the block oil passage app 10 inches from the front and back of the block and tubing it to prevent oil from gushing out around the lifter bodies. I will take detailed pictures when I do my sons but he hasn’t been in the shop mood and I’m not pulling his engine for him.
 
MRGTX
What is the end Use?
Is it Street and strip? Or just strip?
What car would it go in?
What times do you want to run?
How much money you want to spend?
 
Ever hear of an engine shop with a crank grinder? J.Rob


Lol. Yes I have but with three cars I try to stick to a budget. I just had my Calias crank for my 572 cut down to Chevy rod size and by time everything was rebalanced i was looking at a 700.00 bill. I’m not complaining but if I am going to have extra money in a crank it’s smart money building a Stroker. Right???
 
Well one thing I've figured out, you don't need to spin a 5.9/360 SBM to 7000 RPM to make 450 HP considering a built one with decent compression makes 400-450 lb-ft; with decent heads (even EngineQuest "replacement" heads are an upgrade) and cam letting it carry some of that torque past 5500 RPM they'll make plenty of HP. I've learned they aren't as much like the SBC and SBF in that regard, they have a really fat torque curve and don't need to spin nearly as fast as the Brand X engines to make the same amount of power. And they still sound damn good doing it even though they aren't buzzing as high.

BTW I'd be looking at solid-lifter cams if you really want to hit that 7k number, hydraulic setups typically hit trouble around 6200-6500 unless you get fancy with special lifters and valvetrain parts.

EDIT: one more thing lol, that stock beer-barrel Magnum intake is a huge choke point past 5000 RPM or so, going to a high-rise dual-plane alone would probably make a big difference
 
Here's a random video of a pretty nice-sounding 360 shifting at 7k RPM because... well why not lol

Run starts around the 2:50 mark

 
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