377 de-stroked dyno sheets???....

[Guest MKIII91t]

what kind of power can these motor make? they're not talked about much. i did google it and found alot of articles, but none of them have dyno sheets or even mention what kind of power can be had with them. they do mention that they're revvin happy motors. i've also read that the 400 block has cooling problems cause of siamese cylinders?? and go for the 2bolt block and get splayed 4bolt caps for added strenth. any thoughts on this?

[pparaska]

Try the search function, with even just "377" in the Chevy V8 Forum and you'll learn alot about it.

 

The 400 siamese bore overheating thing is BS. If the heads are drilled like they should be, there won't be a problem.

 

IMO, save some money on bottom end parts and valvetrain parts needed to twist the 377 up, and just do a 400. Sure, redline (using the 4000fpm average piston speed maximum) is around 6300, but in a street car, that's alot of rpm, IMO. Especially since you'll have torque from VERY low all the way to 6300.

[Savage42]

Try the search function' date=' with even just "377" in the Chevy V8 Forum and you'll learn alot about it.

 

The 400 siamese bore overheating thing is BS. If the heads are drilled like they should be, there won't be a problem.

 

IMO, save some money on bottom end parts and valvetrain parts needed to twist the 377 up, and just do a 400. Sure, redline (using the 4000fpm average piston speed maximum) is around 6300, but in a street car, that's alot of rpm, IMO. Especially since you'll have torque from VERY low all the way to 6300.[/quote']

 

I'd have to agree. My friend has a 400 SBC in his 240Z. He's been trying to blow it up for years and it's still running strong. It's nothing radical, but has a cam and ported heads. While it only dynoed at only 285HP (flywheel), it's putting out just under 500 ft lbs torque!! Torque is king and it'll light up the tires in 3rd gear at 50 MPH with an automatic. For a street car, it's amazing. He's got a good radiator and it didn't even overheat while running a track day at Thunderhill Raceway in 100+ degree heat. Just my 2 cents.

[Kevin Shasteen]

as for your title of this thread: dont you mean "Detuned" as opposed to "Destroked"? If it was a destroked 377 it would no longer be a 377.

 

I've only found one complete 377 build w/a dyno run in:

 

"The Best of Hot Rod: How To Build Big Inch Chevy Small Blocks", Volume 9. Go to your nearest Barnes & Nobles & it should already be on the shelf.

 

When they built the engine in the article they used an mild Isky 264/272 Roller Cam, Barry Grant 750 Carb, Bow Tie Block decked down to 8.99, Edelbrock Victor Jr. (Single Plane Intake), Edelbrock 212cc Intake Runner Alluminum Cyl.Heads 2.08/1.60 Valves with 70cc chambers. Their pistons gave the engine a 12.5:1 SCR w/1.250 Piston Compression Height: probably not to great for the street on pump gas....you'ld definately want a lower SCR for pump gas.

 

Just because you can rev this combo upto the 7k rpm doesnt mean you have to. This combo has plenty hp/tq below the 5500rpm range. Build it for 9.5:1 SCR and tune the engine for 6000rpm and set your rev limiter at the 5500rpm level: you would still have plenty of kick up to that point.

 

Dyno Test Run as the article built the engine is as follows:

 

RPM's: Tq/HP

4200: 434/347

4400: 454/380

4600: 489/429

4800: 507/463

5000: 513/489

5200: 515/510

5400: 516/530....Peak Torque

5600: 513/547

5800: 508/561

6000: 501/573

6200: 494/583

6400: 483/589

6500: 476/589....Peak HP

6600: 467/587

6700: 459/586

6800: 452/585

6900: 443/582

7000: 435/576

 

It's cetainly an interesting build. The one thing you must have for an engine to rev that high prior to reaching its peak hp is stiff valve springs. You will also need a rock solid botom, premium valvetrain, and oiling system.

 

The option on the block is to either use a stock 400 but then the use of a 350 crank requires bearing spacers. If you use a Bow Tie block then your crank mains can be custom bored to fit the 350 to begin with.

 

Kevin,

[DavyZ]

There was a good article posted on the AFR head site--I think it was a Car Craft article that claimed some very similar numbers to what Kevin posted above. Most interesting though was the quench they were able to achieve and run 11:1 compression on the street using cat pee gasoline.

 

This is a similar article: http://www.airflowresearch.com/articles/article03/A3-P1.htm

 

Davy

[Heavy Z]

Thanks for the article, unorthodox but very practical!

[Heavy Z]

I see 'long rod' 350's around, can a 'long rod' 327 be made? Since the 327 and 350 have the same stock rod length (5.7"), can both motors also then use 6" rods with different pistons? I haven't seen one done but this article Davy posted has me thinking...

 

Thanks

[pparaska]

5.7" rod 327 pistons have a compression height of 1.675"

5.7" rod 350 pistons have a compression height of 1.560"

(0.115" difference)

 

6.0" rod 350 pistons have a compression height of 1.260"

 

With a 6.125" rod (available), you could put a 1.260" compression

height 350 6" rod piston on it and use it in a 327.

That's darned close to thte 6.209" Ford rod they used

in the 353 engine Davy pointed to, and the resulting

Rod/Stroke ratio works out to 1.885:1 instead of the 353's

1.910:1. Hardly worth worrying about.

 

You'd lose .010" of deck height, but that's usually the direction

you want to go anyway. (If you are using a .039" composition

gasket, you want zero deck height anyway, and the

combination of usual nominal piston compression heights, rod length and

half stroke work out to 9.000" anyway, where as the block

has a nominal 9.025" crank CL to deck dimension anyway.)

[grumpyvette]

just some info

theres two basic bore sizes, the 350 block with its 4"-4.060 bore and the 400 block with its 4.125-4.185 bore

many people build 355s by just boreing the 350 .030 oversize with higher compression pistons,and are happy with that, the guys wanting more horsepower and torque build 383s by adding a 3.75" stroke crank, or a 396- 401 with a 3.875 crank and new higher compression pistons, you can make very good horsepower from that engine block and bore size. now if you upgrade to a 400 style block with its larger bore you could build a 377,you could reuse the 350s rods and crank, with bearing spacers in the 400 block with bigger pistons.

But I don,t build many 377s anymore for one very simple reason,

please follow the logic

people build 383s to get the most potential power from that bore size and the 350 block they already have in their corvette for the least cost,for the best resulting power. but a 400 block with its bigger bore is not effectively getting its full potential with a 350 crank to build a 377 you need a 350 crank with a 3.48 stroke and a 400 block bored .030 oversized (4.155 bore x 3.48 stroke x 8= 377.48 displacement)

if you already have the 4.155 bore block and you install a 3.75 stroke crank youll have a 406.77 displacement, if you install a 3.875 stroke crank thats a 420 displacement....... and considering youll make about 1.2-1.4 horsepower per cubic inch of displacement with identical parts and that the combination of the longer stroke and 29-43 EXTRA cubic inches of displacement provide a noticable increase in torque and horsepower, (similar peak horsepower but 30 to 60 ft lbs of TQ more is comon) and that the higher average rpm levels in the 377 tends to get into valve float much more easily... I find its just comon sence to build a 406-420 engine not a 377

 

570 HP

406ci

AFR 210cc Competition Package

10.1

750 Carburator

MSD Distributor @ 36° Timing

Lunati Hyd. Roller Cams 242°-252°

.560-.572 lift 112 Lobe Centers

1 7/8" Hedman Headers

 

500 HP

383ci

AFR Street 190 Cyl. Heads

9.5

Holley 0-4779 750 cfm

MSD Distributor 36° Timing

Comp Cams 12-433-8 Hyd Roller Cam

1 3/4" Headers

most of you will not exceed 450-470hp in your engines, so keep in mind that rods and rod bolts fail far more often then cranks, Id put the money you save buying a good cast crank into a set of (H) style rods with 7/16" rod bolts, a cast crank with good rods and rod bolts thats been ballanced and clearanced correctly should have ZERO PROBLEMS at your power level

 

one piece of advice thou, its almost always best to buy the crank as part of a matched set of parts in a ROTATEING ASSEMBLY KIT and get a FLUIDAMPER harmonic ballancer and if possiable have the INTERNALLY BALLANCED STYLE KIT, as it has FAR LESS stress at high RPMS

heres some places to look

 

http://www.scatcrankshafts.com/

 

http://www.flatlanderracing.com

(stroker kits)

 

http://www.strokerkits.com/383.htm

 

http://www.midwestmotorsportsinc.com/

 

http://www.competitionproducts.com/page88.html

 

http://www.herbertperformance.com/

 

and also remember the cylinderheads, cam, and compression ratio must match your intended hp goals

 

http://www.herbertperformance.com/

Phone

(800) 444-7373

(I buy more kits from these guys , ask for LARRY ext 106) simply because they CUSTOM ASSEMBLE EVERY KIT PART BY PART so you get EXACTLY WHAT YOU ASK FOR,NOW THAT OF COURSE REQUIRES YOU TO THINK THRU YOUR PART LIST AND ASK FOR THE CORRECT MATCHING PARTS (heres what I comonly ask for in a 383 kit) be very specific as to the brand and part number of parts included in the kit if its important to you!they will try to save you money with cheap parts if you don,t get specific in your parts list! ITS YOUR FAULT NOT THEIRS IF YOU DON,T GET THE CORRECT PARTS ORDERED

 

internally ballanced crank (cast or forged)(depends on hp level, 450hp or below go cast, forged is to some extent wasted money)

MATCHING (H) style rods, set up for floating pins and main bearings that fit your block(350 size mains)(400 size mains)

(H) style 5.7 or 6" rods

with 7/16" bolts

forged pistons for floating pins(MUST MATCH RODS and be .030-.060 oversize) with matching light weight pins and locks and be the correct cpr

matching rings

quality ballancer

race quality flexplate

ARP oil pump drive shaft

have assembly ballanced either by them or locally