HighHopes85

I have a hard time understanding why everyone these days is opting for the 383 combo. I realize it is tried and true, but do you really need the torque for such a light car? Why not destroke the 400 with the 350 crank and make something that has a little less bottom end but can rev high (quicker?)?

Back in the day, this was the engine I had always dreamed about in high school. Am I the only one who had these aspirations? Tell me a 377 has some merit to it...-Matt-

gkull

I had aspirations of the 377 idea. Every combination from 368 - 427 small block cost the same to build. Where motors have come a long way is metals. Years ago engines had two main limitations. Feet per minute of the piston and the valve springs.

Today it's no problem to swing a 4-inch stroke SBC 7500 rpm. I'm also sure that a long rod 406 with internal balanced lightweight small journal crank would kick but on a 377.

Years ago I built a destroked .060 over 350 with a 3.25 stroke, which ends up as 337 ci. It was a very successful attempt to win in a circle track class limited to one two-barrel carb with Iron heads. Nobody likes to get beat and the car got teched after every race. I think that it worked better because of 20 less cubic inches made better use of the carb CFM limitations and we were able to run about 500 extra rpm over the best 358's.

On the street we do not have rules and limits. So a 40 lbs or so pound crank with a 3.750 stroke 383 is equal to a 377 in power output until you go above 2.10 intake valves where unshrouding comes into effect.

J Z06

Because TORQUE is fun! And 383's are reliable if not more so than the motor it replaces. High winding motors can be a lot of maintenance...Who wants that? Most of us want to get in, turn the key...and waste that snob in the 911 on the way to the track.

My 383 is also more "SMOG" friendly than the 350. It passed IM/240 here in CT cleaner than the 350.

Lastly.. the 377 in John Lingenfelters Book is NOT the ticket to longevity/performance.

want2drivemy85

a few months ago, one of the car magazines (car craft, or hot rod i think) did a heads up comparo between the 377 and the 383. both had nearly the same torque, but the 377 had a little more horsepower. of course the 377 peak power was a little higher in the rpm range. with peak power coming in at a higher rpm, wouldnt it be easier/better for launching??
i think it boils down to what YOU want for your car. personally i like revs, and the 377 to me would be a better choice over the 383.

CORKVETTE1

with everything being equal the longer stroke will be quicker

Beach Bum

I didn't really give a destroker a thought when I did mine... at the time I had access to a 350 4 bolt in perfect condition that just needed cleaning up and clearanced... so it was no brainer for me. Not sure about other areas, but out here it seems good 400 blocks seem to be getting rarer and rarer.

later
Beach

KNEVER

If I had a 400 block I would build it.

427Hotrod

Same 'ole question.. what do you intend to do with it?

A 377 is a very viable motor on the street. Think of it as a 350 that breathes REAL well if you put some decent heads on it. And if you have decent heads you might as well rev it a little harder and take real advantage of it.

A 383 is a great combo also. If you want to make more torque down low (as compared to a 350) and not really rev all that high and use the parts associated with that rpm, then it's the way to go. Of course if you want to rev it high, it will do that also. But to feed the extra inches it gets harder with the smaller bore.

If you're going to build a 383 it would pay to build a 406. You get the big bore and the same stroke. Best of both worlds!

I am very impressed with the way some guys get these 383 suckers to run deep 11's on motor on pump gas with an auto and 3.07 gears. Unreal!!

I think a 377 could easily do it too and a 406 could do even better!

MoMo

Hey, I can see the merit in destroking a motor. I'm doing it myself. 427 blocks are getting rare, especially 4-bolt versions. So I took a 454 4-bolt block and destroked it with a 427 crank. I wanted a higher rpm motor that still had guts down low, but then really turned into a monster at upper revs.

By destroking, you reduce piston speed and therefore increase the safe rpm limit that the rotating assembly can take without metal fatigue concerns.

And I have a 400 block that I'd like to destroke to a 377 to stick in an IROC Camaro, actually.

However, let's look at a potential problem with building a high revver on today's pump gas. An rpm engine likes a long cam duration, generally. Nice lopey idle, and a high revving torque band. Problem is, you go much over 220 degrees at 0.05" lift and it won't clean up at idle for the sniffer test. And a 220 degree cam will only give you about 5500 rpm.

So if you're limited by smog regulations to a small cam and 5500 rpm type range, why not build a stroker, so you don't HAVE to rev it much? That way, you get the torque (which is real power) without the rpm burden.
The 383 is an excellent and economic choice for today's pump gas limitations.

So I can see both sides of the equation.
I'm thinking about a cam change every two years for the smog police. And then build the 377 engine that IROC's were meant to have. A 2 week hassle every 102 weeks, but all that performance in the meantime!

Another big factor is the increasing rarity of good 400 blocks. 350 blocks are cheap and plentiful. If you have a 400, a 377 is a good choice. But a 406 would make an incredible street engine, so that's something else to think about.

Comes down to what kind of manners you want your Corvette to have. High rpm dynamics or tire ripping torque? The 383 will blow away challengers off the line. The 377 will almost do as well, but will really shine as your rpm's build up. I think the 377 would be more fun, given the right cam.