I was talking to a neighbor who's very wise in the ways of muscle motors and he said he was going to build an engine with a huge bore and tiny stroke, because he had never done it. I assume this would mean high revving, and not a whole of torque? that might depend on the setup though. Have any of you guys tried something like this?

 

That's what makes the 302 such a fun motor. 4 inch bore with a 3 inch stroke. The .060 over 327 would be your next step. You can destroke a 400 by using a large journal 327 crank and that will give you a 350. Large 4.155 (.030 over) bore with a 3.25 stroke. That would be interesting. I am trying a 377 this summer. That's the same as above except with a 350 crank. Both motors need bearing spacers for the crank. I run 327s in what ever I have. There is nothing like a high winding solid lifter motor. The 327 revs very fast. I hope the 377 is close to it. If not, I might try the 350 CID
4.155 X 3.25. Have fun, Lou

 

I'm getting ready to install the 3.25 stroke 400 block (353 cubes with a 4.156 bore) into my C2. I also love driving the 327, and wanted more power. This combo seems like it should be everything the 327 was and more. Sure, I could have monster torque with a 406 (or 421), but I like driving down the front straight at Butonwillow shifting from 3rd at 6500 RPM.

For a purely street driven car, the short stroke might be a mistake, but for street/track cars I think they are the way to go. The 377/380 is very similar, with only a quarter inch more stroke the stress is not that much more. If you want a bit more and stillhave the long rods, Speed-o-Motive has a 3.562" crank to make a 386
http://speedomotive.com/386_chevy_long_rod_stroker.htm That could be the basis for a similar version of this destroked 400.

 

This is one of the reasons we built a 522. By keeping the stroke down & using bore, I now have a big block that can actually live close to 8K rpm. Building an engine is all about what the goal is. My engine builder dropped the stroke down this season & found that he was no longer developing enough torque off the line. Mine is for the street, his is pure track. It's all about what you are trying to accomplish.

 

What kind of power are you making?MErlin 522

 

Depends upon how much boost we run. Dyno is coming up shortly. I expect at least 1,000HP & about 1,100 LBS of torque with the 12psi pulleys we have on. I'm then going to take that info & have Whipple make me some 30psi pulleys & go for broke. I'm thinking we could get as high as 1,500HP, but that won't be on pump gas. Pump gas limit is probably somewhere around 1,200HP.

 

who said that 1200hp is the limit for pump gas. For example a 632CID Merlin engine running 8.5 to 1 compression should make 650hp and 725tq considering it has good flow in and out. Then run 20psi On that and you get 1500hp and like 1700ftlbs of tq. But these arn't that accurate of numbers but you could go a certain amount of boost on a certain amount of compression and can excede that 1200hp mark. I think another example would be that Monty has a 427CID engine that makes an amazing 1200hp thats like 2.8hp per cube and this is on pump gas. So if you use a 632 big block the same way you could get more than 1200hp on pump gas. But dang 1500hp, your not using an IRS are you? ;)

 

You're making too many assumptions here. 20psi on a turbo, roots & twin screw will all make different numbers. 632 is 110CI greater than I am running, so that is also a factor. You also need to factor in what kind of intercoolers are being run etc. Turbos clearly make excellent HP, but their torque numbers are considerably lower. My system will more than likely develop more torque than HP. You will also find the torque curve to be flatter & hit far lower in the rpm range - usually a good thing for racing, but bad for the street. The 1,200HP number I gave you is a best guess given our compression ratio, CI, cam, heads, boost, intercoolers & everything else. These numbers are gathered from other Whipple installations in similar configurations. My numbers could vary by as much as 200HP in either direction. 1,200HP is not THE limit for pump gas, I expect it to be MY limit. The next engine I am planning will likely have a pump gas limit of close to 2K HP. It will definitely be a turbo installation. I too was very impressed by Monty's numbers :yesnod:

 

WWWHHHHAAAATTTTT!!!!!!!!! 2,000HP STREET CAR. What kind of transmission do you bolt behind that? I'd be scared to get into that car. You know I have an Idea.
Get an SUV(GM of course) then get a 632ci engine in that with that crazy azz twin turbo, maybe quad turbo and get 2000hp. Then get 24inch rims on that and fill them up with like 16inch rotors with 6 piston calibers. all around.
Anyway for the turbo problem because it creates more hp than torque this is why I'm going with a blower on top of a 482CID or 525CID big block and get 1200hp and use this as a street legal drag car. I see what you mean by using different power adders and different combinations on bore and stroke to achieve the owners goal in the way the car performs. I see that you want a street car more than a drag car. I would think that more torque would be a good thing for a street car because when your coming out of a corner you could use that extra torque you have to sling your car out of the corner?

 

Read this post http://forums.corvetteforum.com/zerothread?id=417719 you will find it quite entertaining. It also outlines my plans. Furthermore, the purpose of the post, originally outlined by Monty is the ridiculous power you can derive from turbos. Now imagine bringing that from 522CI up close to 800. I know this whole thing is a little stupid & impractical, but doesn't it at least peak your curiousity? It does mine. I firmly believe that a very low compression monster block with the proper computer system & turbos could be made fairly streetable yet be able to be wound up past the 2K mark - all with some fairly simple adjustments to the onboard computer. The biggest issue is strength. I have seen a number of 4L80E's rated to 1K. The application that I am planning will be going in a full chrome moly tube chassis. It's funny, having built this crazy car of mine I already feel that it could be so much more. Anyway, we'll go out & drive it for a while and then see if I still feel the same. I still find myself stomping on the pedal of the Viper & saying "it sure would be nice to have more"...

 

Hey Merlin, If by chance you realize that you with all that torque your about to create, and as a result you may just end up breaking your 6 speed down to it's lowest elemential form. If this is perhaps realized and you decide to throw something a little stronger behind there. Let me know, I would be more than willing to give you a pretty penny for all that.

It's so funny going to honest Performance and hearing everyone gawk and commit on your CAR *cough cough* I mean monster. Everyone always is saying how that is the most insane machine they have ever seen. I have to agree, it looks like it needs to be placed behind some glass in D.C. next to the bill of rights or something.

 

Dont you just love those Big Blocks. :yesnod: :yesnod:
Well the only problem is that I would go out and find a strong chasiss car or a little big one(I love the corvettes but I dont think they have enough engine room for this) And then stuff that monster 632CID Merlin Big Block 8.5 to 1 compression egnine down into the engine bay. Stiffen up the car with a heavy guage( maybe 3'16'' of an inch or something or 1/4 inch?) and but some fat Drag radials out back. Make this monster have 4 doors, count em 1,2,3,4 doors. Reason too scare the crap out of you and your freinds. Then get 4 turbos (600hp each) and stick them into the headers of the engine.
Another thing I was thinking you could have electonically controlled butterfly's or vavles to open exhaust flow to a certain # of turbos at a time. For example your at 2500rpm and your almost maxing your two turbos making 1200hp at that rpm then mash the gas and the vavles slowly open up exhaust flow to the other two turbos gradually as the rpm's increase. This way you still max out those 2(600hp turbos) and slowly start to spool up powwer on the other two. This way the potential of the engine could be 2,400hp( but due to the fact that their is power loss, intercooler efficency and heat you get you 2kilo hp.
Another Idea I have, Run two intercoolers in the same fashion as the callaways which are to the sides of the intake. Then you could have small electric fans that would rush cold air over the intercoolers to cool the boosted air. To feed the fans you could put scoops or hood louvers which would feed the electric fans that accelerate air over the intercooler cooling the boost making them more effective in cooling the air. I hope someday I have a big $$$ to make projects like these that I think up of. :yesnod:

 

Where do put the intercooler. I would think that to make that much power the intercooler would need to be much bigger than what will fit in a vette

 

Oatboy / Bcwaller

The 352 (4.155" bore X 3.25" stroke) is what I plan on building for my next motor. Actually I'm collecting parts and I haven't even got my motor running yet. I found this article while kicking around on the web the other day. I dont like the ford rods but It shows that these motors can build some good torque numbers over a wide RPM range and have fewer problems with detonation. Good luck! :crazy:
http://purplesagetradingpost.com/sum...%20engine.html

 

Stingcrazy, Thanks for the link. I have had a copy of that article since it came out. I too fantasize about doing something different. As for the rods, Crower makes a SBC 6.25 inch rod. That way you would not have to machine the crank for the Ford rods, kinda keeps things more standard. I can only imagine what that combination would have yielded with the Fast Burn Heads and the Hot Cam Kit.

 

You dont, you put it on a car different than a Vette, Like a big body car. MAYBE?

 

Stingraycrazy,

I have had that article cut out since the magazine came out as well. The engine builder who I got the engine from built it a few years ago based on the article, but with better heads and cam. I do think I have the Ford rods, but he says they are 6.3" rods.

Dyno2000 specs it out to over 400 TQ from 2000-6000, peak TQ of 477 at 4500, and peak HP of 464 at 5500. I could easily go with a more radical cam, and drop the bottom end torque a bit. A different cam could change this to 480 TQ at 5000 and 528 HP at 6500, but it would have 50 less TQ at 2000. If I ever get the need, a cam swap is easy! ;)

Could be he's wrong, but here's what he said is in the engine:
2-bolt 400 block, magnafluxed, bored (4.156" bore) and honed with torque plates, squared and decked, align honed, and with ARP main studs.
All clearances blueprinted and Block has been squared and decked to .010" deck height.
All oil gallerys have been smoothed and all casting flash removed from the oil drainbacks.
Melling HV oil pump with blueprinted clearances.
3.25" forged 4340 steel crankshaft (original GM piece for a 327), lightened, cross-drilled and chamfered, and polished.
Forged 6.30" Ford 300" I-6 connecting rods. Polished beams, shotpeened, ARP 'Wave-loc' rod bolts installed.
New Oliver/King's bearings
JE custom forged ultra-light pistons.
File fit Speed Pro moly rings
Entire rotating assembly has been internally balanced
SFI approved Fluidampr balancer
All clearances have been blueprinted, and it uses Oliver/King's bearings throughout.
Custom ground Comp hyd. roller camshaft, 220/228 @ .050", ~0.5" lift, with 114 lobe center
Comp tie-bar roller lifters
Comp springs, retainers, and locks
Crane rocker arms.
Cloyes True-Roller timing chain
MSD 6A
Holley Avenger Carb
Edelbrock Victor Jr. heads, milled to drop the chamber to 58cc
Edelbrock Victor Jr. intake

 

Sounds great Bcwaller,

Now strap a Turbo on that thang and lets make some numbers!! :crazy:

A few things I would add to your build. Try a Performer RPM intake instead of the Victor Jr. My 1st motor made more low end torque and higher top end horse power with the RPM. Also average HP and TQ were better with the RPM. I had both flow tested and was surprised to find the RPM beat the Victor by 27 CFM!! Give it a try.

By the way, what is the BOB weight on your rotating assy? Do you plan on keeping the Ford rods? I found a set of JE pistons with a 1.125" pin height and some billet Lentz 6.250" rods on the cheap @ EBay. Allot of new parts have come to the table since that artical was written. So l@@k around. That Kenny Duttweiler is one smart dude... :crazy:


[Modified by Stingraycrazy, 4:09 AM 11/26/2002]

 

The motor is complete and in my garage. All I'm waiting for before I install it is cash from the shipping company that dropped it in shipment, and then I can replace the oil pump, pickup, and pan. Since this was a refresh of a motor that was built a few years ago, it has what it has. But the price was reasonable compared to all new parts, and I got a good deal on labor as well.

I could do an intake swap at some point, but first I want to get the thing in and set up. I'll dyno the car to see what the rear wheel numbers are, and then we can all come up with ideas on improvement! :D

 

well, this is not always true. Most civilized ;) turbo set up make more TQ then HP.

My buddies TT supra makes 411 HP and 440 TQ
I was looking at the single turbo Z06 thread, 437 hp and 545 TQ...

Just a couple of examples, and I am not saying it is the norm.


Merlin,
Look into why big displacment engines are not being turbo charged. I have been looking around and most Turbo race engines are in the 500-522 cube area max.
I think someone finally did a 611 or something like that. When you look at 700+ cubes, I wonder why no one has done it yet. I was wondeing if it had to do to the flame travel in such a big engine.

Also the bigger the piston the longer it takes to displace the heat to the cylinder bores, so a bigger piston could make detonating an issue

Just something to think about.