MRL 340 for the 21st Century

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replicaracer43 said:
A "street" engine with peak torque at 5500, and peak power at 6200?
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Damn straight! Did you look at the torque curve, if you can call it a curve. Don't look at 1 line and pick out what you want to see, look at the whole sweep. It made 430tq at 3500rpm. That will get you moving in a Damn quick hurry.

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replicaracer43 said:
A "street" engine with peak torque at 5500, and peak power at 6200?
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That's what a 340 will do and allways did and was allways a typical kind of curve with a short stroke and a big-ish - cam. I don't see anything out of the way that makes me scratch my head saying WTF is going on there.

Mikes engine is really nice and shows how a 340 is known as a screamer of an engine on those high winding small blocks. A reputation they have allways had!

Love the graph Mike. They allways help out a lot. No crazy dips or wacko peaks, nice lines.
 
Excuse the ignorance, but is it common practice to start a dyno run at 3500 rpm? Does the dyno limit the rpm spread from low to high?
 
MRL Performance said:
So here are some of the comments that were on the original thread, the voting for a stoke stroke or stroker 340. I love this ****!

"it will be more of a challenge to pull off a 550HP 340" Maybe not

"for that many hp, you need to increase the cubes as much as possible to keep the rpm in a range the valve train can live a long happy life" 6300 is just right

"So when selecting power you want depends what you consider streetable but probably in the .9 to 1.2 hp per cid (408 would be 370 to about 500 hp) street strip 1.2 plus hp per cid" 1.56hp per ci, and streetable

"A 375 hp 408 that puts out 475 plus torque makes a very nice street engine" Id rather have 539 and 476 LOL

"The best 371 I ever built and tested made 489 ft/lbs @ 5400 rpm IIRC and 542HP @ 6900 rpm. I don't know if I have anything in my bag of tricks to do that with a 27 cube deficit. This will be interesting for sure. That 371 in above post was 10.8 static and cranked 195-200 psi --this is borderline pump gas" 9.8 static and 165psi cranking pressure for this 340

"I think, if streetable is to be considered (by a buyer), then you will need to rev it higher to get that figure. Only way to make those figures are more "bangs" per minute. So make it happen and share the particulars. I'm a skeptic - I'll say it's not a big deal on a dyno to make that number with any package. But in a chassis - as a 340 - with a 7K peak? It's not going to happen without some rather fancy tricks and systems. In other words - lots of money and not streetable for the vast majority of users" Still a "Skeptic"?
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Some of the comments prove how little some folks really know about torque and horsepower. I voted for the stock stroke 340. As you pointed out, the only real disadvantage it has it a tall compression distance. God knows I have begged everyone I could to make a 6.525 rod with a 2.125 crank pin. It would essentially be a .400 long BBC rod with the Chrysler rod throw. I'd even leave the .990 pin bore in it. That would drop the compression distance down to a reasonable number, reduce the bob weight and IMO the higher R/S ratio would help the restricted intake tract, and reduce pumping losses across the exhaust.


Great build Mike! The price is very reasonable, the results are most excellent. A well thought out, kick *** engine that won't need it's guts RPM'd out and will embarrass many engines with 5/8 inch or more stroke.
 
yellow rose said:
Some of the comments prove how little some folks really know about torque and horsepower.
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You said it Bro. I know some just dont know, but when I get questioned about EVERYTHING, I love proving my work. It makes us ALL better in the long run. Like I said, I put MY MONEY where my mouth is. Dont see a lot of that around here, but a lot of Mouths for sure.
 
Hey, I'm not trying to be a smart ***, just seems odd to have a torque peak so high and call it a street engine. And your dyno sheet is a peice of paper, if you wanna "put your money where your mouth is" like you stated, put it in a car and make some passes...if it makes that kind of steam, it will fly!
 
MRL Performance said:
"for that many hp, you need to increase the cubes as much as possible to keep the rpm in a range the valve train can live a long happy life" 6300 is just right
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And this is one of the reasons I voted stock stroke.

As nice as strokers are. I'm just not as convinced they are the end all be all like some folks. I think it's a lot more interesting to make that power with stock stroke. And to prove that you can do it at a reasonable RPM as well. Dispel some of the old notions out there.
 
replicaracer43 said:
Hey, I'm not trying to be a smart ***, just seems odd to have a torque peak so high and call it a street engine. And your dyno sheet is a peice of paper, if you wanna "put your money where your mouth is" like you stated, put it in a car and make some passes...if it makes that kind of steam, it will fly!
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If it had peak torque at 2000 RPM what good would that be?

Don't look at the peaks, look at the curve. That thing has enough torque below peak to boil the hides any time you want. Besides, that high peak torque number just means it will accelerate much quicker and recover from gear changes better.
 
And to think I got some hate for my "Hot rod bliss" thread. Simple is always better. Funny when a big wig says it more people listen.

No offence, Mike. Great job.
 
All you guys can say what you want, I don't build engines to sell to people, but when a guy DOES build engines to sell, and uses a high "dyno sheet" I tend to like real world proof of the numbers, that's all.....I have seen lots of these over "500 dyno HP" engines that were smoke and mirrors deals. Not saying this one IS, just need more than a happy paper before I go celebrating it as the best thing ever
 
replicaracer43 said:
All you guys can say what you want, I don't build engines to sell to people, but when a guy DOES build engines to sell, and uses a high "dyno sheet" I tend to like real world proof of the numbers, that's all.....I have seen lots of these over "500 dyno HP" engines that were smoke and mirrors deals. Not saying this one IS, just need more than a happy paper before I go celebrating it as the best thing ever
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I cannot agree more! Which is why I would love to see some real worlddrag strip numbers from an MRL, or any other professional engine builder on here. Not that I doubt anybody, but proof is always nice.
 
mopowers said:
Excuse the ignorance, but is it common practice to start a dyno run at 3500 rpm? Does the dyno limit the rpm spread from low to high?
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The dyno isn't run limited. Time wise.
You can start the dyno run darn near anywhere BUT if you all ready know you're cam is large, then you know that the power level below a certain point isn't of any real I interest If it is a important point for you, then you can have your operator pull it that low.

If your worried about low torque that low down, perhaps a smaller cam is for you? Do take note of the cam used.

248*@.050. The Hyd. MP 292/.509 cam has that duration at .050. It's power range is listed at plus 3000 rpm. Listed as a bracket cam/drag. 12.5 second bracket or quicker.

With a cam like this, are we really interested in put putting around town?
Ha ha ha ha ha....

Why people worry about low rpm power with big little cams and large cams is beyond me.
 
great job mike on the bad 340, the combo you reccommend me and sold me parts for went 6.60 s at 104 in a full weight 74 duster on pump gas 416 cubes
 
Sorry, but 1.38 lbs/ci @ less than 11-? Damn-that's....trails off , bows, waves cap and....J.Rob
 
MRL Performance said:
So here are some of the comments that were on the original thread, the voting for a stoke stroke or stroker 340. I love this ****!


"The best 371 I ever built and tested made 489 ft/lbs @ 5400 rpm IIRC and 542HP @ 6900 rpm. I don't know if I have anything in my bag of tricks to do that with a 27 cube deficit. This will be interesting for sure. That 371 in above post was 10.8 static and cranked 195-200 psi --this is borderline pump gas" 9.8 static and 165psi cranking pressure for this 340
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^^^^^^^^^^^^^^^^^^^^^^^^^^^Well you are achieving the impossible. Because 165 psi is weak where I come from (thanks for posting that though) Also your peak torque RPM and you're HP peak don't make sense. Pleae help me understand. If peak torque is X then peak HP should be X + 1500+- (200rpm). Why is your engine peaking so early? If it could carry then WOW! J.Rob
 
I would still love to see what a combo similar to this (optimized to run on 87 E10) would do.......
 
The torque is flat, like really flat. It made peak torque for a long time. It made 470tq for 1000rpm, who cares where the actual peak bump is. It has a Fat broad power curve and it comes on early and carries it for a long time.
This engine has very little friction. The short block had 8.8ftlbs of turning force. Plus it was running very efficient 100%ve for most of the run.
 
MRL Performance said:
The torque is flat, like really flat. It made peak torque for a long time. It made 470tq for 1000rpm, who cares where the actual peak bump is. It has a Fat broad power curve and it comes on early and carries it for a long time.
This engine has very little friction. The short block had 8.8ftlbs of turning force. Plus it was running very efficient 100%ve for most of the run.
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If you have VE then you must have a air turbine right? How much air does it move and what does the CFM curve look like? Does CFM drop off and reduce after 6200 rpm? J.Rob
 
I gotta say there Mike, I'm a believer. I know you've experimented for a long time on building punting-pahtoot stock stroke small blocks.

It also make me wonder what will happen to anyone else, should they be bold enough to publish what they have done, if it exceeds normal expectations.

I suppose if Cody and I fail miserably with the LAX heads on the stroker, at least some people will feel sorry for us..........that's what we will do.........we'll only tell about it if we fail......that way we don't have to put up with a bunch of poopoo.

Okay then, I'm off to work on the failure!
 
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