To Stroke or not to Stroke?

340 550HP, But how???

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    91
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x2 on the "moon" comment...
Getting off of the discussion of only power level... I'd also like to understand if the horsepower is on a dyno, or as installed in a chassis (meaning chassis available headers, belt driven water pump, air cleaner, etc.)? Are we using a commonly available, street type ring pack and shelf parts aside from a camshaft? What are the expectations in terms of longevity and maintenance? What about overall cost to purchase? Are we simply ignoring all those factors?
 
Well, again, this is like that word "driveability" or "streetable" It depends on the person driving it. To me, the Moon for the street is 7000rpm, so if I can make all the power before that i would be happy. But thats not the whole story. It still has to make good power 500-1000rpm past peak to be considered a good performance engine. It wont see that end of the rpm scale very often, but it should have the moxy there when you need it.

So with all that said, Im going to shoot for 6500rpm as a peak, but hold peak power to 7000rpm for those times when you need it.
 
moper said:
x2 on the "moon" comment...
Getting off of the discussion of only power level... I'd also like to understand if the horsepower is on a dyno, or as installed in a chassis (meaning chassis available headers, belt driven water pump, air cleaner, etc.)? Are we using a commonly available, street type ring pack and shelf parts aside from a camshaft? What are the expectations in terms of longevity and maintenance? What about overall cost to purchase? Are we simply ignoring all those factors?
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While I appreciate these thoughts, I don't really care how Mike does it as long as he shares. J.Rob
 
MRL Performance said:
Well, again, this is like that word "driveability" or "streetable" It depends on the person driving it. To me, the Moon for the street is 7000rpm, so if I can make all the power before that i would be happy. But thats not the whole story. It still has to make good power 500-1000rpm past peak to be considered a good performance engine. It wont see that end of the rpm scale very often, but it should have the moxy there when you need it.

So with all that said, Im going to shoot for 6500rpm as a peak, but hold peak power to 7000rpm for those times when you need it.
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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. J.Rob
 
Sure ya do Ramm, more cam, compression, head,....... Lmao!
 
rumblefish360 said:
Sure ya do Ramm, more cam, compression, head,....... Lmao!
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And then streetability suffers along with the pump gas requirement. That 371 in above post was 10.8 static and cranked 195-200 psi --this is borderline pump gas around here and I wouldn't sell it to just anyone either .But I don't have to tell you that. J.Rob
 
The last real HP 360 I did made 534HP @ 6300rpm and 485TQ @ 5150rpm. That was a flat tappet cam, Old school Weiand intake, and EZ EFI. It still made 500HP at 7000rpm, in fact it made 500+ from 5450-7000rpm. I only had so much dyno time and it still needed a little tweaking, was running a tad on the lean side for max power(13.3 a/f). 10.6 scr and 190psi. Still pulled 10in vacuum at 900 idle. So, I think with a different cam(SR), and a few internal tweaks(tricky but not exotic), my goal of 550hp at 6500rpm is doable, maybe LOL

Pic of the 360, she sure is purdy

MRL 360HP.jpg
 
MRL Performance said:
The last real HP 360 I did made 534HP @ 6300rpm and 485TQ @ 5150rpm. That was a flat tappet cam, Old school Weiand intake, and EZ EFI. It still made 500HP at 7000rpm, in fact it made 500+ from 5450-7000rpm. I only had so much dyno time and it still needed a little tweaking, was running a tad on the lean side for max power(13.3 a/f). 10.6 scr and 190psi. Still pulled 10in vacuum at 900 idle. So, I think with a different cam(SR), and a few internal tweaks(tricky but not exotic), my goal of 550hp at 6500rpm is doable, maybe LOL

Pic of the 360, she sure is purdy

View attachment 1715011098
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The Weiand 7576 X-Celerator is one the best street single planes there is--wish they still made 'em. J.Rob
 
MRL Performance said:
The last real HP 360 I did made 534HP @ 6300rpm and 485TQ @ 5150rpm. That was a flat tappet cam, Old school Weiand intake, and EZ EFI. It still made 500HP at 7000rpm, in fact it made 500+ from 5450-7000rpm. I only had so much dyno time and it still needed a little tweaking, was running a tad on the lean side for max power(13.3 a/f). 10.6 scr and 190psi. Still pulled 10in vacuum at 900 idle. So, I think with a different cam(SR), and a few internal tweaks(tricky but not exotic), my goal of 550hp at 6500rpm is doable, maybe LOL

Pic of the 360, she sure is purdy

View attachment 1715011098
Click to expand...

How fast has it gone and at what weight?

I agree on the Weiand, I have one I bought for $100 years ago that was a display on the Holley truck.
 
I’ve love to see you bore the 340 .020 over and run a 3.58 crank. Then build it to idle well, run clean and make around 450 horsepower. Something that is smooth and tractable, that could be lugged down to 1200 rpm in overdrive and pull cleanly when asked to accelerate without shifting down and run hard all the way to something like a 6200 rpm redline. Basically a 6.1 without the cost and extra parts of a Hemi swap.

Build an LA that shows that you don’t have to swap a Hemi into your car to get all the same benefits.
 
DionR said:
I’ve love to see you bore the 340 .020 over and run a 3.58 crank. Then build it to idle well, run clean and make around 450 horsepower. Something that is smooth and tractable, that could be lugged down to 1200 rpm in overdrive and pull cleanly when asked to accelerate without shifting down and run hard all the way to something like a 6200 rpm redline. Basically a 6.1 without the cost and extra parts of a Hemi swap.

Build an LA that shows that you don’t have to swap a Hemi into your car to get all the same benefits.
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Been there, done that. I did a 360 a while back that was .060 over, so the same thing. It made 430HP and 455TQ, idled at 800 with 17in vac. Pulled good to 6000. HFT cam too.
 
MRL Performance said:
Been there, done that. I did a 360 a while back that was .060 over, so the same thing. It made 430HP and 455TQ, idled at 800 with 17in vac. Pulled good to 6000. HFT cam too.
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Sweet! Wouldn't have a thread on here about it or anything, would you?

Add a roller cam and EFI and don't think I would ask for anything more. :thumbsup:
 
RAMM said:
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. J.Rob
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All you have to do is use a different dyno, easy peasy
 
Sounds good. 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.
 
rumblefish360 said:
Ummmmm, yea, OK, your an expert!!!!
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Well, you know what an "expert" means don't ya..lets break it down...
"ex"= once was...has been...washed up... and "Spert"= a drip under pressure.
So an expert is... a once was, has been drip under pressure???
 
This is a great idea for a thread, I only wish I could have thought of it sooner.... LOL
 
almost ready for the dyno. Stock 340 with Hilborn Fuel Injection manafold converted to EFI. I'm not going for big HP (I was going for the look) but down the road you never know!

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Mike, I would love to see what YOU could do with a stock stroke W-2 headed 340. But I know it won't happen.
 
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