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short stroking high revving v8

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Guest Anonymous

What would i need for this?

 

I think i have this down. a 383 is a 350 block bored and using a 400 crank. This would give you tons of torque due to the long stroke right? But long stroking motors dont seem to rev that high, is this true?

 

So what im wanting to do is build a 350 block up, but i want it to rev high and have a really good topend. what would i do to get a short stroking 350? Can i put a 305 crank in and get shorter stroke rods? or can i jsut leave the 350 crank in and find shorter rods? Im sort of new to this, so any help would be nice.

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The most desirable SBC for those who want to rev is a destroked 400; typically to 377 using a 350 crank.

 

For a 350 block you will have to step down to 327 or 302.

 

You will have to change the crank to change to stroke, you will probably have to change the whole rotating assembly, but the crank determines the stroke.

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Guest Anonymous

thanks, thats basically what i needed to know.

 

id love to get my hands on a small block 400 but NO yards around here have one. and i dunno if its worth to pay for shipping to buy one off ebay.

any suggestions?

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It really depends on what you want to do and mostly how much money you have! I am doing a 377, which should be back from the machine shop soon. I decided to go this route since I want a fast/higher reving engine with the power band a bit higher so I don't just sit there and spin. Also I wanted about 450 hp in a reliable, streetable engine. It will be easy for me to have this with the 377.

 

So you have to weigh how much money you have versus what you want to end up with and how much time you want to wait.

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Guest Anonymous
It really depends on what you want to do and mostly how much money you have! I am doing a 377' date=' which should be back from the machine shop soon. I decided to go this route since I want a fast/higher reving engine with the power band a bit higher so I don't just sit there and spin. Also I wanted about 450 hp in a reliable, streetable engine. It will be easy for me to have this with the 377.

 

So you have to weigh how much money you have versus what you want to end up with and how much time you want to wait.[/quote']

 

I think you and i are looking for the same thing, I like a nice high revving motor with really nice topend and a higher powerband. What work have you done and what has it ended up costing? Cost isnt really an issue as i am single and live alone.

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Guest gprix1

If I were doing a motor again and using a 400 block I would pass on the used 400 block and go with a World Products Motown block ($1,749.95 at Summit).

 

That may sound like a lot but conider this, a junkyard 400 engine block can still be a great deal, but don't overlook the hidden costs. A used block will need to be cleaned and magnafluxed (~$45), bored and honed with a torque plate (~$189), align-honed (~$100), and surfaced (~$110). That adds up to ~$450 plus whatever you paid for the core. It also assumes that the first core you came up with passes the crack check and isn't already bored to the limit. Most used 400 blocks have been around for some time and are very close to or at the limit.

 

The World Motown block is obviously a much bigger initial investment. However it's a brand new block that can be had in the deck height of your choosing, 350 or 400 mains, has thicker decks, beefier cylinder walls (it can be rebuilt more times), nicer main caps with splayed bolts, and the ability to be built up to 454 ci at little more than it would cost to make a 406ci out of your stock 400 block (or de-stocked if you choose to go that route). And the World block's rigidity will make more power with better ring sealing, the mains and decks are already done, and it still uses standard Chevy components so no special parts are required.

 

This is the route I will go on my next engine build. In fact, I'll just get the complete 427ci internally balanced short block for $4,594. Should go nicely with my ported Dart heads and reworked Holley 850 DP currently on my 383.

 

Motown block info(bare block)http://www.worldcastings.com/docs/03catalog/motownblock.pdf

 

Motown short block infohttp://www.worldcastings.com/docs/03catalog/engines.pdf

 

Motown bare block - Summithttp://store.summitracing.com/default.asp?target=search.asp&type=bysummitpart&searchtype=both&part=WRL-084010&x=16&y=5

 

Short block - Summithttp://store.summitracing.com/default.asp?target=search.asp&type=bysummitpart&searchtype=both&part=WRL-101205&x=16&y=11

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Heh, good question... I'n not sure I want to know how much this thing is costing me! Actually I really haven't kept track! I 've gotten KB 194 pistons for 6 inch rod. I got the rods from scat, the forged 4340 I beam with 7/16"cap screws, and a scat 9000 crank. The crank is really cool since it is 400 mains (no spacers) and for a 6 inch rod. I had the machinest balance it internally so I don't have to deal with the 400 balancer or flywheel. I also found a set of used canfeild aluminum heads that have been pocket ported, those cost $900, which was a great price. I am going to use a cam recommended by grumpyvette, which I will get when I get the engine back. I also have a T-56 trans, so I also need to get a bellhousing from weir, which will let me use a normal flywheel/clutch. I have a centerforce clutch and an aluminum flywheel. I think with all this it will rev really fast and high, and not have too much low end.

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Guest Anonymous

I know is aid money isnt really a concern, but DAMN 1700 for a block?

 

I think ill just wait around and see if a yard comes up with a 350 and just stroke that motor. Hopefully it wont be cracked.

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Guest Anonymous

I would go with the 350 if you want a higher reving motor. In order to get higher revs you have to have the bigger heads to supply the air and the bigger cam and stronger bottom end to keep it from coming apart. If you are worried about spinning of the line get one of the MSD new digital ignition boxes so you can retard your timing of the line, which kills the torque and horsepower and have it come back in gradually to keep the tires from breaking loose.

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383 will have NO problems with 7k RPM if you build it for it. If you are building for 10k RPM then your going to need a nasty cam which will leave you with no bottom end power to speak of. The big question is WHY would you do that? If you are limited by cubes for your race class then do it, otherwise 7,000-8,500 RPM is not even an issue with a 383 if you build for it. The SCAT cast 3.75" cranks are rated for 7k RPM.

 

I've seen a 377 dyno vs a 383, the 377 makes a tad more top end power and a tad less bottom end (less than 10 HP) with the same heads/cam/intake. Not enough difference to speak of IMO.

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Guest Anonymous

I dont want a motor that revs to 10k

 

I want something that doesnt start to fade after about 5500 rpm. something that will pull hard up top to take advantage of gearing limitations.

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Guest POKINATCHA

Don't know if any of you guys follow the threads on the L-series forum, but they're talking about stroke vs. rod length right now, too. Somebody mentioned an article on AFR's website that ran in Hot Rod awhile back about a destroked 400 (352 at the end) that was running 11:1 on 87 octane :shock: It was setup to be pretty cheap and pretty much scrifice topend completely for torque, but it still made more than 400 hp. Its a cool article to read if you're toying with stroke combinations.

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Guest Anonymous

what about a 350 bored .030 with a 283 crank?

 

wouldnt that make a 305 similar to the first '67 z28?

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I dont want a motor that revs to 10k

 

I want something that doesnt start to fade after about 5500 rpm. something that will pull hard up top to take advantage of gearing limitations.

 

Evil, you dont have to look any further than a 350 if thats all you want! My setup should pull great to the 6000 - 6500 range. Pretty much all I have is a 350 with a solid lift steet strip cam, good breathing heads and a good flowing intake.

 

My setup could turn a little higher maybe 7K but I went with a pretty small camshaft for the street. If you want specifics on what I am building let me know but you shouldnt have to destroke anything if all you want is 6500-7000 RPM.

 

When you are only talking about 7K you really dont want to give up any cubic inches.

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Guest Anonymous

WOO that link kicks ASS

 

there is hope afterall

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Stock LT1's and LT4's rev quite freely to 6300 RPM. Just need to open up the breathing, maybe some roller rockers.

 

Yep, the LT1 wont breath much at high RPM and it doesn't have the cam for it, past 6200/6300 roller rockers are a "must" and thats why the LT4 got em. I ran mine to 7k with no problems.

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I dont want a motor that revs to 10k

 

I want something that doesnt start to fade after about 5500 rpm.

 

Then your looking for love in all the wrong places :D You need to cam it' date=' and get some headers/intake work that will let it breath. If you put a torquey cam in there then dont expect your RV to pull to 7k RPM and like it, power will fall off with a small cam at high RPM thats just how it goes. High RPM V8s will go lump-lump at idle if you know what I mean. I ran a 234/246-110 and it ran great to 7k, and with 3.42s (T56) still had enough balls down low to daily drive without slipping the clutch like nuts. Would have had even more impressive timing work if I had access to 92 or better octane, down low had to be a little conservative with 91 MTBE.

 

[/supraexcuse']

 

Where do you want peak RPM to be? That will be one thing deciding what cam to go with, and if headwork should be done or not, yada yada.

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Guest Anonymous
I dont want a motor that revs to 10k

 

I want something that doesnt start to fade after about 5500 rpm.

 

Then your looking for love in all the wrong places :D You need to cam it' date=' and get some headers/intake work that will let it breath. If you put a torquey cam in there then dont expect your RV to pull to 7k RPM and like it, power will fall off with a small cam at high RPM thats just how it goes. High RPM V8s will go lump-lump at idle if you know what I mean. I ran a 234/246-110 and it ran great to 7k, and with 3.42s (T56) still had enough balls down low to daily drive without slipping the clutch like nuts. Would have had even more impressive timing work if I had access to 92 or better octane, down low had to be a little conservative with 91 MTBE.

 

[/supraexcuse']

 

Where do you want peak RPM to be? That will be one thing deciding what cam to go with, and if headwork should be done or not, yada yada.

 

peak RPM? or peak HP?

 

If you are talking about HP im thinking around 6k maybe 6.5K

 

RPM i dont know yet.

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