377 SBC??

[grumpyvette]

Just picked up a package deal on a couple of mid 80s C10s. One long bed one short both 2WD. The long bed is a pile but has had a lot of new parts. One of them being a new motor. Just form a quick look I could see things like a brand new Holley, new headers, 461/462 Heads, intake, new exhaust.

The deal was good just in parts. the motor was kind of a Bonus.
I dealt with the girl friend mostly and after I committed to the deal the owner calls to let me know that the motor is a 377 de-stroked 400 with just 1000 miles on it. Trans is a brand new T350 with a Hughes kit and a new 2500 stall converter.

If he was going to lie I'm sure it would have been a 383 or a 406. not a 377.

The coincidence to all this is the day before I bought the trucks I was doing research on building a 377 for my Camaro.

Anyone built one? Feed back? pros cons?

obviously without knowing the complete list of parts used, your forced to guess , but a correctly built 377 can produce very impressive power.theres certainly a hundred various ways to build a 377 and make good power,
generally when I build a 377,its going to be used with a manual transmission, and a solid lifter cam, to take advantage of the upper rpm power potential,and Im concerned with long term durability,
the whole idea of a 377 is to use the larger 4.125-4.155 bore size of the 400 sbc block , with its larger bore comes a larger piston surface area and in theory more potential torque ,with the shorter stroke of the 350 sbc,to maintain the higher rpm potential of the shorter stroke 350, the issue is that the 400 block has a larger main bearing size requiring main bearing spacers
http://www.ebay.com/itm/King-MB5224AM-S ... 0920386516
or
http://www.summitracing.com/parts/cca-5620
or BUY THE SCAT ROTATING ASSEMBLY
377 4-400-3500-6000-3 2-350-6000-2100QL 3.500" 6.000" SRP PROF 4.155 FLAT 11.0 1-40578 1-40578BI

http://www.strokerkits.com/product/chev ... l-pistons/

http://www.flatlanderracing.com/scc-4340super.html

https://www.jericoperformance.com/5speedroad.htm

generally when I build a 377,its going to be built to take advantage of the upper rpm power potential,of the 350 reasonably short 3.5" stroke and the 400 sbc larger bore size youll want heads and a cam,design, that will allow the engine to breath, and the best durable rotating assembly made from forged components that will allow you to safely spin 6800rpm, I try to use 6" connecting rods,forged pistons,1.6 roller rockers, and get the compression up in the 11:1 range and use a SOLID LIFTER cam like a crane 110921,with the correct duration and lift , matched too, 200cc-215 cc heads(dart, trickflow, brodix) and a single plane intake (edelbrock 2925) in a fairly light weight car with a rear gear ratio near 4.11:1, 800cfm-850 cfm holley and long tube 1 3/4" headers. the key here is letting it breath efficiently at 4500rpm-6800rpm if you want to make good power, this obviously required matching cam duration,compression ratio, head flow, intake and exhaust design, to that intended rpm band

Edelbrock Super Victor SBC part #2925

getting a combo like that in the 470hp-500hp at the flywheel power range is usually not difficult

http://www.jegs.com/i/Brodix/158/102100 ... tId=760699

http://www.jegs.com/webapp/wcs/stores/s ... flow+210cc

http://www.summitracing.com/parts/tfs-3 ... /overview/

Is coil bind height and open height the same thing? The springs I'm wanting to go with have an installed height of 1.940 and open height of 1.250. With .600 exhaust lift, does that give me .090 before coil bind?

installed height is open height, the springs set up to provide a minimal resistance before it can be compressed further, the cam card below may help

notice the listed info

A BIT OF QUICK RESEARCH


Crane Cams#271-99846-16
Single Valve Springs
Outside Diameter: 1.255"
Inside Diameter: .870
Seat Pressure: 125 LBS @ 1.800"
Open Pressure: 383 LBS @ 1.200
Coil Bind: 1.100"
Rate (LBS/IN.): 428
Max Lift: .640
Set of 16

http://www.jegs.com/i/Crane-Cams/271/99846-16/10002/-1


notice the coil bind height PLUS, approximately the .090 is the listed max lift, and the max lift on the cam or open height is a bit less.
engines require clearances to work correctly and with valve springs having a bit of extra clearance helps durability, this is generally one reason WHY cams are sold with a strongly suggested set of load rates and clearances so they can operate under know and expected stress levels they were designed for


the 215cc vortec heads are a potentially useful choice but obviously matched components like the intake and valve train must be used, like the edelbrock 2913 INTAKE
viewtopic.php?f=52&t=266&p=40004&hilit=215cc+vortec#p40004

 

[Strictly Attitude]

I used to always want to build a 377 rpm high rpm monster engine

 

[grumpyvette]

for those guys who wonder why anyone would build a 377 by de-stroking a 400 block , with a 350 sbc 3.48' stroke crank, rather than keeping the 400 sbc 3.75" stroke crank,
a good point! but I can also see the advantage of the higher rpm operational power band , in some combinations.
the reason i and most other guys generally build a 406 vs a 377 is that the extra displacement and stroke tends to generate nearly the same peak power but a bit more torque, so if your not running in a class that has displacement to weight ratio limits, (example you car can weight a minimum of 7 pounds per cubic inch) the 406 sbc tends to be a bit faster combo in the same weight car, provided its properly geared to match the power band of course