What would you build if limited to 372ci - with boost as an option

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273 said:
Exactly what I was thinking cheap, got a decent bore to stroke ratio should be able to spin it fairly high if needed to, lots of high flowing head options, even port out stocker can get you pretty far, custom pistons the only main negative. 371.95 cid 4.185 x 3.38
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Where would that put the pin in the piston?

You have a very long pin height and a long piston. Even if you used a Line2Line coating you’d still have compromised ring seal. Higher rpm would only make it worse.
 
Why would you not look at doing a R5 motor send the crank out have it restroked 4.185 bore A P7 heads will out flow a max wedge head any day of the wk Larry Smith just did a set for me before he past away and they go over 425cfm with a 2.20 valve theses motors can still be brought right if you look around im sending a crank out now to restoked to 3.50 with a 4.220 bore gets it to almost 395 cu to have the crank restoked is 1000-1200 bucks Id talk to Eddie Middleton he just built a motor for a guy that races in the silver something its called and he whent 242 mph in a old cup car
 
Newbomb Turk said:
True but the R/S ratio is still too high.

I was giving examples of how I’d build it. And that’s the math that comes out.

Which BTW is pretty close to the deck heights in Pro Stock. IIRC they are in the 9.200 range with about a 3.6xx stroke.
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That's just a little over a stock 400 lol
 
Newbomb Turk said:
Where would that put the pin in the piston?

You have a very long pin height and a long piston. Even if you used a Line2Line coating you’d still have compromised ring seal. Higher rpm would only make it worse.
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It's in the 1.9ish range
 
I would build a 372 kyobb motor at 6.5:1 and sling a 6-71 on top over driven 15% or more with an old style Hilborn FI and run it on methanol or nitro.
 
RustyRatRod said:
I would build a 372 kyobb motor at 6.5:1 and sling a 6-71 on top over driven 15% or more with an old style Hilborn FI and run it on methanol or nitro.
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Methanol or nitro moves the record another 50mph!
 
Newbomb Turk said:
Where would that put the pin in the piston?

You have a very long pin height and a long piston. Even if you used a Line2Line coating you’d still have compromised ring seal. Higher rpm would only make it worse.
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?

I'm taking 361 B engine stock stroke, if he went custom piston sure he could add longer rods if he wished, what rpms is the OP going for ? Imagine it ain't crazy high since it's a budget build.
 
Does engine have to be conventional piston? Newer rotary engines can put out some scary HP and ungodly RPM at equivalent combustion size. As well as reduced weights.

I'm sure rules limits or penalizes use. But if you're building outside the box? Don't be afraid to think outside the box?
 
273 said:
?

I'm taking 361 B engine stock stroke, if he went custom piston sure he could add longer rods if he wished, what rpms is the OP going for ? Imagine it ain't crazy high since it's a budget build.
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If it’s a 1.9 pin height ring seal will be compromised too much.

Or you end up with a R/S ratio way too high.
 
If you didn't like my idea of the r block, a destroked hemi would be a great idea. They actually use to race this combo.
 
cojohnso said:
Does engine have to be conventional piston? Newer rotary engines can put out some scary HP and ungodly RPM at equivalent combustion size. As well as reduced weights.

I'm sure rules limits or penalizes use. But if you're building outside the box? Don't be afraid to think outside the box?
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The class is a classic category. No EFI, no controllers, etc
 
RustyRatRod said:
More prize money.
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There are no prizes, no money, no trophies. just a line of text in a book if you break a record. LOL, and the only ones who even see the line of text are the other competitors. Ultimately I want my red hat. No thoughts that I can actually achieve that, but have to have some sort of goal, yes?
 
RustyRatRod said:
More prize money.
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Post 41 shot that in the foot lol.

I was told by a very smart man way back in 1990 that burning nitro is the same as burning 1,000 dollar stacks of bills as fast as you can.

That was right after a magneto malfunction banged a blower off right outside his shop.

Luckily no one got hurt. And he was pretty good with nitro.
 
LO23M8B said:
If you didn't like my idea of the r block, a destroked hemi would be a great idea. They actually use to race this combo.
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The up front cost of the R motor is my only worries there. Looking at options that can be put together. I have a 383. 400 and 360mag at home. The thoughts of BBC rods (cheap and strong), a reground crank, etc feels more possible (not that it is in the grand scheme).
 
71GSSDemon said:
There are no prizes, no money, no trophies. just a line of text in a book if you break a record. LOL, and the only ones who even see the line of text are the other competitors. Ultimately I want my red hat. No thoughts that I can actually achieve that, but have to have some sort of goal, yes?
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Gotta be some lot lizards hangin around up there. I'm sure they'd give you a prize.
 
LO23M8B said:
If you didn't like my idea of the r block, a destroked hemi would be a great idea. They actually use to race this combo.
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Newbomb Turk said:
Post 41 shot that in the foot lol.

I was told by a very smart man way back in 1990 that burning nitro is the same as burning 1,000 dollar stacks of bills as fast as you can.

That was right after a magneto malfunction banged a blower off right outside his shop.

Luckily no one got hurt. And he was pretty good with nitro.
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There is a roadster out there that runs 1/2 a hemi. One bank of 4 - other bank is empty, flat plane crank, Hilborn injection on 100% nitro! 200mph 4cyl!
 
71GSSDemon said:
The up front cost of the R motor is my only worries there. Looking at options that can be put together. I have a 383. 400 and 360mag at home. The thoughts of BBC rods (cheap and strong), a reground crank, etc feels more possible (not that it is in the grand scheme).
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If those are you choices and you want to be competitive I’d build the BBC and not look back
 
Newbomb Turk said:
If it’s a 1.9 pin height ring seal will be compromised too much.

Or you end up with a R/S ratio way too high.
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Well that seems to be the pin height, it maybe compromised but people been building stock stroke/rod B engines for years, I imagine he could find some chevy or custom piston and rod solution if he wanted.

Just saying no need for custom stroker a 361 fits the displacement bill it's an option he doesn't have to choose it.

Also a 0.060" over 360 fits the bill.

I like replicaracer43's solution too.
 
273 said:
Well that seems to be the pin height, it maybe compromised but people been building stock stroke/rod B engines for years, I imagine he could find some chevy or custom piston and rod solution if he wanted.

Just saying no need for custom stroker a 361 fits the displacement bill it's an option he doesn't have to choose it.

Also a 0.060" over 360 fits the bill.

I like replicaracer43's solution too.
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I am liking all of these solutions and the discussions. My biggest question was small block vs big block for 372ci and why
 
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