i'm learning sbc here; so here's an engine combo; somene pos

[Guest Speaker]

ok this is the idea i've got together so far for an engine

 

400ci block

Superlight Scat Crank for 350ci; 5.7" stroke

(yes thats the $1200 one)

Scat forged H-beam rods; 5.7"

TRW forged pistons...

Some kinda cam; Competition Cams Xtreme Energy camshaft 224/230 @ .050, 268/280 adv., .502"/.506" lift, 110degree lobe sep.

(found that on speedomotive's website)

good for high compression

Brodix 23degree heads -> 67cc chambers, 225cc intake ports, 2.08"intake valves/ 1.6" exhaust; they're supposed to flow 270-280cfm

and a Victor Jr. intake port matched with complete internal balancing...

 

now i dunno what kind of compression ratio i can run on pumpgas with that kind of lobe seperation; i'm figuring its gonna be around 10.5:1

 

any ideas on what kind of power this could make? add a properly sized holley 4-barrel w/ vacuum secondaries; and that cam setup is a complete roller; hydraulic right? i'm learning here... and all the other typical stuff to match this; roller rockers, etc...

 

i hope this will be a MONSTER engine hehe

 

 

 

[This message has been edited by Speaker (edited March 21, 2001).]

[Peternell]

I'm was also considering a 377 for my 74 260z, cause I have most of the parts for it and it would be a Great RPM engine, however I'm not in the same league as you when it comes to bucks.

 

Heck I was going to put the 377 together w/a Chevy 350 steel crank and spacer bearings, SCAT 6" rods, a 400 4-bolt block and some #186 camel hump heads with port work and 2.02's & 1.60's for about the price of your crank alone.

 

However I've opted for the 406 route, cause I'm after torque for drag racing and longer stroker means power at lower RPM's which = less stress on the whole engine.

 

"There's no replacement for displacement" - don't mean to start a war here guy's, I know the benefits of NOS and super trick parts and machine work, I'm talking $ for $.

 

One suggestion, consider the 6" rods, they are well within your budgets and have many benefits.

[Guest Anonymous]

Desktop dyno shows 411hp at 5500, with 438ft-lb at 4500. The Cam that I show for Comp Cams XE268 has less lift. .477 and .480 lift. Send me an email if you want a screen capture of it. chris.d.tretta@intel.com

Ct..

[Guest Anonymous]

Speaker,

 

With those intake ports the motor may seem a little "lazy" on the bottom end. You may want to consider a smaller head like the AFR 190s, Edelbrock Performer RPMs or even the Trick Flows.

 

With all of that forged stuff in the bottom end you should be safe to rev the motor but will be limited more by the hydraulic cam. You may want to consider a mild solid roller cam. This would allow the motor to rev higher which is the purpose of the 377 anyway.

 

Chevy High Performance did a buildup of a 377 and a 383 a few months back. I want to say they achieved ~450hp out of both motors with the Trick Flow 23* heads and a Comp Cam solid roller.

 

One other thing, if you are going to use TRW forged pistons I would check the weight. Some TRW forgings are REALLY heavy. An affordable alternative would be the Wiseco Pro Tru line.

 

Chris

[Ray]

I agree with the other guys here the cam is to mild for the heads and the lower end, if you are building that much of a lower let it rev.

 

If you are going to spend that kind of money why not build a Honda rod motor. Alot of the drag and sprint car guys are building them. What they use is the smaller honda rod bearing size on a chevy style crank. lighter rotating assembly and stronger rods... The drag guys are spinning the motors over 9k and the sprint car guys are loading them real hard in the 7 to 8k range. The cranks run about 1600 and the rods 700 to 800. All the other stuff is the same. They rev really fast !! You are in the heart of Nascar, you should be able to find a couple of different engine builders that have built a few and know about them. The Sprint car guys came up with it so I would start there. Since this is a relatively new combo ask alot of questions of alot of people.... Good luck

 

------------------

Remember it is only a piece of metal.

 

[This message has been edited by Ray (edited March 22, 2001).]

 

[This message has been edited by Ray (edited March 22, 2001).]

[Dp351zcar]

Speaker you also might check on the pin of those rods. I know I am building a ford but I think this will be the same. My eagle H beam rods are for a floating pin and TRW does not make a piston with pin locks at least in my engine. I had to go with JE pistons. If those are the same type of rods, then as per what I was told they are heaver than the stock rods and the TRW pistons are heavy also.

I don't know, I am just a ex pontiac fan building a ford (I can't belive it myself).

 

[This message has been edited by Dp351zcar (edited March 22, 2001).]

[DavyZ]

I totally like the combo--sounds like an awesome engine!!! I would look at piston options, though. The one statement about TRWs being (relatively) heavy is true. You can do better. With a balanced bottom end, that thing should do wonders...and last a long time!

[Kevin Shasteen]

My Comp Cams Catalogue is a 98 catalog & shows the XR276HR-10 cam to be exactly what was posted earlier...w/the exception of his .506 lift as my catalog has the exhuast lift at .510......everything else is identical as to his earlier post.

 

Remember; when you're considering components for CFM you need to calculate the formula:

 

a) "RPM x Displacement/3456"

 

Once you have that answer divide it by the "#" of cylinders on your engine...in this case there are "8" cyl's.

 

c) After you get that answer multiply it by 1.5; this "1.5" factor is a mild correction & takes into consideration the restrictions placed on airflow by the intake runners.

 

The final answer gives you what each cylinder must flow w/the intake & exhaust combined. Run the formula & you'll see that your combo is definately gonna suffer on the low end as those cyl.heads are flowing way more air than you'll be needing at low rpm's.

 

Your engine package (Camshaft/Intake/Carb) should be based on a total package deal & not just the "Cool Factor" of having a neat engine: (I too want a 377).

 

If you want to take the "Guess" work out of which cam to use you first have to decide:

1) Your basic RPM (most often driven rpm/mph)

2) Vehicle Weight

3) Transmission

4) Rear Gears

5) Tire Size

 

(6) Another possible variable is/if you plan on racing your car; what are your expectations in the 1/4 mile. This is sometimes a good reference as to how fast a car is compared to other cars.

 

Once you know the answers to the above you can then pick a camshaft that will allow your engine's powerband to peak at the appropriate RPM in a given environment; voila-No Guess to it/kind of scientific once you think about it!

 

If you'ld like help choosing a cam....just post (on this thread):

 

1)What your car weighs,

2)What trans you are going with,

3)What you'ld like your car to run in the 1/4

4)What size tires you're going with

 

With that in mind we can determine what rpm's you'ld be doing at the 1/4 mile traps; once we know you're rpm's we can then look at an appropriate cam.

 

Kevin,

Yes,Still an Inliner)

[Guest Anonymous]

Kevin,

That is true for the XR - roller, but not the XE. I was trying to match the name. Thanks for the clarification.

Ct..

[Kevin Shasteen]

quote:

---

Originally posted by Speaker:

....Competition Cams Xtreme Energy camshaft 224/230 @ .050, 268/280 adv., .502"/.506" lift, 110degree lobe sep

---

 

Sorry; your correct XE/XH-whatever it takes!

I thought I read somewhere on this thread that he was looking for a Hyd.Roller; However, it turns out it wasnt his comment but someone else's suggestion to go w/a Hyd/Mechanical Roller.

 

The XE268H-10 does only have .477/.480 lift.

 

Sorry for the confusion.

 

Kevin,

(Yes,Still an Inliner)

 

BTW: