377 cid non stroker

[try2pas]

Anyone ever heard of a 400 with a 350 crank making it a 377 which is close to the 383 in displacement but with the shorter stroke of a 350 (3.48)? Pros and cons?

 

[Corvettes White]

This was the orgional way of buildiing the motor before all the kits came to the market. Can not speek to the +'s & -'s but typically the 400 used and external balance and I have hear that they are not that common at the junk yards as they once were. George

 

[Hib Halverson]

The 377 certainly makes for an engine that will rev higher but, as 999 says, good, useable 400 blocks are harder and harder to find in wrecking yards.

The problems with used 400 blocks are
1) core shift
2) blocks that are already 030 over

If you can find one with minimal core shift and a standard bore which you can take .020 or .030 over, you'll be set.

You have to buy special bearings which have the 350 "large-journal" ID but the 400's even larger OD.

 

[zachh]

Buy a Merlin block from Summit or Jegs.... it usually runs about $2000.... You need to bore them 30 over and have the inside of the block cleared out. I believe Summit sells a kit with the new pistons, rods, bearings, etc. They are normally calles a 377 E-torquer or E-stroker. They rev up extremely fast and have a very high redline rpm (depending on the head and cam configuration. They do tend to be a little sluggish off the line (depending on how its tuned and built). Most, if not all 377s will be externally balanced... but depending on the kit thats bought, thatll be an easy fix. Any questions, let me know..
best wishes
zachh

 

[Crimson Thunder]

I'm just wondering,what length rods would you use?Would the 5.7 rods from the 350 work or would you need to use the short rods from the 400.It seems that if you are stuck with the sorry rod-ratio of the 400 you would be better off not giving up the the 23ci and just building a 400.

 

[zachh]

350 rods, and crank with 400 pistons. On a 383, you use a 400 crank and rods and a 350 piston. Thats why theres a 383 and a 377. The shorter stroke revs up faster than a longer stroke and it rev higher. Thats all, torque is lost at low rpms, but theres more hp at top end. It makes an exellent drag racing engine...
zachh

 

[Hib Halverson]

I'm just wondering,what length rods would you use?Would the 5.7 rods from the 350 work or would you need to use the short rods from the 400.It seems that if you are stuck with the sorry rod-ratio of the 400 you would be better off not giving up the the 23ci and just building a 400.

Whether it be a 377 or a 400, there no reason to use the 5.56-in 400 rod length.

You're better to use a 5.7-long rod then have pistons made to give you the pin height that you want.

 

[Jack]

Anyone ever heard of a 400 with a 350 crank making it a 377 which is close to the 383 in displacement but with the shorter stroke of a 350 (3.48)? Pros and cons?

Yes ... they're popular in circle track racing. I have one for sale if you want ... 30 over 400 block ... steel 350 crank ... 6" manley I beam rods ... manley platinum forged domed pistons. The 377 (destroked 400) is usually INTERNAL balanced. On the other hand, a 377 (stroked 350) using stock bore 350 block & a turned 400 crank is usually external balanced.

Chevy cup motors are loosely based on a 400 block (about 4.125" bore) w/ 327 stroke (about 3.25") ... that is until just this season ... now they're beginning to use a similar bore/stroke ratio but based on the LSX series motors. Maybe counterintuitive & contrary to popular belief ... but ... cup motors have solid FLAT tappet cams ... busch & truck have solid roller cams.