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laketex 10-10-2000 10:48 PM

A few engine questions
 
Dreaming about a new engine for my blazer and here's what I've come up with. I'd really like a stroker motor, have built one in the past but am far from an expert. Now my new PAW catalog came in...so...

They offer a 377 kit with a 4 bolt main block, 2 pc rear main, 3.750 crank, 5.565 rods, TRW forged dish or flattop, rings, bearings, camshapt, timing chain, balanced for $1795 unassmebled. Now for $2395, you get all the above plus World Products SR heads, lifters, pushrods, oil pump, gaskets, long slot rockers.

Now about those SR heads, are they really just stock replacement? Cause if so, I'd much rather have vortecs right?

Also what's the diff between 377, 383, and 388. We built a 383 which I was told was a 350 bored .030 over with a 400 crank. Always thought a 377 was a destroked 400 (400 block bored over, 350 crank) But could be wrong.

According to this catalog, 377 is std bore, 383 is .030 over, 385 is .040 over, and 388 is .060 over .
But then they turn around and say that 388 is a 350 block, with 3.750 stroke and 5.7 rod and a .060 bore.
Also say that a 383 is a 400 block, with 3.480 stroke and 5.7 rod and .060 bore.

Is there more than one way to get a 383? advantages/disadvantages to both? And how do I calculate these numbers for myself?

And if I decide to run FI, what cfm will I be looking for running a 400 horse stroker motor?

Thanks guys, I know the engine gurus out there can help.

Bryan

[img]/wwwthreads_images/icons/smile.gif[/img][img]/wwwthreads_images/icons/tongue.gif[/img]
LakeTex
Durant, OK
'79 Blazer almost running! ----need a money tree----

dave 10-10-2000 11:22 PM

Re: A few engine questions
 
With any engine purchase, make sure you understand the details. It is possible to build a 377 with a 3.750" stroke crankshaft.

GM is now offering an HT 383 engine. http://www.sallee-chevrolet.com/Chev...8s/HT_383.html [img]/wwwthreads_images/icons/smile.gif[/img] It's more expensive than a PAW engine or PAW engine kit. The GM HT 383 is a NEW engine that has Vortec heads and an intake installed, along with the sheet metal installed. The GM HT 383 also has a much better warranty than any PAW engine or PAW engine kit! If your dreaming of an engine dream of the NEW GM HT 383!
dave


TEX 10-11-2000 10:14 AM

Re: A few engine questions
 
<font color=purple>Yes, there are multiple ways to get 377's, 383's, etc. A .060 over 400 destroked with a 350 crank (3.48") would be about 383, as would a stroked .030 over 350 with a 400 crank (3.75"), OR the new 383 from GM mentioned above which is an UNbored 350 with a 3.8" crank. The rod length does not make any difference in displacement, but longer is better if you are looking for HP (you have to make sure you use pistons MADE for whatever length rod you use or it will position them incorrectly in the cylinder - or OUT of it). The formula for displacement is:

(bore/2)*(bore/2)*3.14*stroke*# of cylinders

For example, let's look at that .060 over destroked 400:

(2.0925)(2.0925)*3.14*3.48*8 = 382.76 - rounded up is 383.

Now, the stock bore 377 stroked from a 350:

(2)(2)*3.14*3.75*8 = 376.8 - rounded up is 377.

And so on...........</font color=purple>


TEX

http://sites.netscape.net/gumboracing



laketex 10-11-2000 10:42 AM

Re: A few engine questions
 
Thanks guys....so in your experiences what should I do?

I'm not looking for a mud racing engine, just one with some trail torque...I'd like to get around 400 ft/lbs of torque down low. But I have also been toyoying with the idea of nitrous injecting this engine and turning on the juice for sand drags, mud drags, and playing downtown on saturday nite. So some decent hp figures would be nice too. And all this on a budget of under $3000. Got any ideas or tips?

Thanks again

[img]/wwwthreads_images/icons/smile.gif[/img][img]/wwwthreads_images/icons/tongue.gif[/img]
LakeTex
Durant, OK
'79 Blazer almost running! ----need a money tree----

chevota 10-11-2000 11:24 AM

Re: A few engine questions
 
As a general rule the motors are "nick-named" using .030" over. So a 4.030 bore(350 block) x 3.75 stroke(400 crank) is a 383, and a 4.155(400 block) x 3.48(350 crank) is a 377. Renaming beyond that is just confusing.

I would stay away from the 383, especially the 5.565 rods. Of the two I would go with the 377. It is stronger, will rev better and higher, make more horsepower and torque, last longer, and get better mileage. The 383 will make more torque way down low, like at idle, but that's it. And the torque will probably not be noticable. It has more friction, will suck more gas, make less horsepower, and if you use 5.565 rods you're engine will be a joke. You'll also need the bigger heavier 400 harmonic balancer and 400 flexplate.

If I were you I would consider the 377 vs the 400. The 400 will really make torque.
You will need to get 5.7"(350) rods for it. 6.0" would be great if you want $pend the cash. The disadvantages are out weighed by the power! This is of course my opinion, the 400 is my favorite motor. I've ran the piss out of the two I have. My second choice would be a 377 if I had to choose. The 377 will easily make 400ftlbs torque at whatever rpm band of cam you choose.
Either one will work great with Nitrous too.


Chevota

Andreas 10-11-2000 11:31 AM

Re: A few engine questions
 
The longer stroke is good for torque, as you probably know. The de-stroked 400 (377) is a winding machine. The 377 could probably put out some serious torque too, but thatīs like missing the point [img]/wwwthreads_images/icons/smile.gif[/img]. Itīs a racers engine for high rpms.
Try to find a nice sb 400 instead, maybe even as a shortblock. Then you could add whatever heads & intake etc. you want. Thatīs what I wouldīve done if I could do it again [img]/wwwthreads_images/icons/smile.gif[/img]. And if I had the $$ Iīd go with a small blower (4:71 or 6:71) instead of a NOS shot

Andreas

If a Blazer runs smooth, it isnīt really a Blazer[img]/wwwthreads_images/icons/crazy.gif[/img]

TEX 10-11-2000 01:17 PM

Re: A few engine questions
 
<font color=purple>Yeah, I have to agree that if you're considering an engine based on the 400 block, go with the 400/406/408/etc. No sense taking cubes AWAY from the 400 (by making a 377) when it's torque that you're after. The short rods are okay as long as you don't plan a lot of RPM's, but 5.7's are definitely better & 6.0's are the way to go if you can swing 'em.</font color=purple>

TEX

<font color=purple>Doesn't PAW have a 421" budget engine? Hmmmmmmmmmm</font color=purple>

http://sites.netscape.net/gumboracing



**DONOTDELETE** 10-11-2000 03:16 PM

Re: A few engine questions
 
I myself am thinking of building up a new smallblock next summer, my current plans are to take this short block crate engine from GM Performance parts, http://www.sdpc2000.com/cart.asp?act...id=514&pid=621 and then putting an Edelbrock Perform TBI Package on which comes with cam, heads, intake, and new chip for the computer. which is mostly everything that the short block doesnt come with, put on a bigger cfm throttle body, MSD off-road Ignition, new water pump, oil pump, serpentine system, pulleys, a 100 hp "dry" shot of nitrous, and umm a couple more things I cant remember off the top of my head.


laketex 10-11-2000 03:38 PM

Re: A few engine questions
 
I don't know about that shortblock. For $1200 I'd think you'd get a lot more than that. Also don't know that I'd run nitrous with cast pistons. I'd say that's asking for trouble. My opinion only, you see how smart I am [img]/wwwthreads_images/icons/laugh.gif[/img].

So you think 400 is the way to go? I currently have a 350 shortblock '94 crate with 60K on it to work with, but I could always trade it for a 400. What about the 400 heads cracking? Still a big problem? Will vortec 350 heads work for this application or too small?

Another thing, I've heard that the crate 350s aren't too good for rebuilding...due to not so good blocks. If I did a 377 with this motor, would it hold up? Thanks for all yalls input. It's all appreciated but dang I'm a novice in the motor dept.

Also, 89silverado, what's this performer TBI pkg? Is that for folks that already have a fuel injection? I'd sure like to inject this new engine, but am not too sure who to go with. I was leaning toward Howell though....

Bryan

[img]/wwwthreads_images/icons/smile.gif[/img][img]/wwwthreads_images/icons/tongue.gif[/img]
LakeTex
Durant, OK
'79 Blazer almost running! ----need a money tree----

Andreas 10-11-2000 04:17 PM

Re: A few engine questions
 
Yeah, I agree with the $1200 shortblock. For that kind of money you could get a 400 shortblock with steel crank, forged rods & pistons and put as much nitrous through it you ever want.
Cracking 400 heads....well...ummm...I guess it depends a little on what casting you get (Iīm a d*mn novice too[img]/wwwthreads_images/icons/laugh.gif[/img]). The chevy head pre-heater runner, which leads exhaust gasses through the intake is a weak point and can be "blocked" with a special intake gasket I believe?
The vortec heads will be ok on a 400 but probably needs steam holes if those arenīt drilled at the factory?

Hehe, Iīm actually asking more questions than giving answers here. Iīll shut up[img]/wwwthreads_images/icons/crazy.gif[/img]

Andreas

If a Blazer runs smooth, it isnīt really a Blazer[img]/wwwthreads_images/icons/crazy.gif[/img]


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