Steve89GTA

350HO GM Performance Parts 350.
Scoggin Dickey TPI Manifold
TPI with 22ib injectors
1 5/8 headers

Do you guys recommend keeping the cam that comes with the 350 HO? What is the compression ration of this motor?

Also, I believe this is basically the package recevied with the scoggin dickey tpi create motor selling for 3400US. Although, it includes a pretty wild cam (hot cam is it?). I don't think i'll be able to pass emissions with that cam/motor.

Regardless, I'm pretty sure the block is the standard GM 350 HO block available for 1250US or so. The heads are Vortec's and the manifold is their own creation. 357hp is great but I'm thinking the cam may be a little overboard for my intentions AND that I may be able to save a ton of cash. Don't get me wrong, I want the most power per dollar/but I'm willing to trade driveability and reliability as well as passing emission for 40-50HP.

1250 for the long block
500 for the vortec heads
440 for the scoggin manifold
300 for a cam? (Something a little less potent than what's in their setup??)
total: 2490 (ish). Almost $1,000 savings. hmm. Then again, their engine will come fully assembled and with a warranty.


My goal is to have 300 wheel HP and 300foot ibs of torque at the wheels.

Last set of questions:
Does anyone have the scoggin TPI engine installed? I want the idle to be DEAD smooth. Will this thing hunt and such with this cam? What will my mileage be like with this thing?

Here's a link to the motor:

http://www.sdpc2000.com/cart.asp?act...=1577&pid=9009

unknown_host

iTrader: (1)

Compression is 9.1:1, the cam is pretty mild, I would leave it in if you want a smooth idle (and dont want to void the warranty on the motor right off the bat). TPI will kill power output on that motor tho...

unknown_host

iTrader: (1)

And now that I see that last comment, there is no way in hell that my 350HO when it ran 12.8's at 106 was making 300 rear wheel horsepower, and that was with a good intake and a speed demon 650 carb. There is no way you will make 300 rear wheel horsepower with TPI on that motor, let alone without an idle.

Steve89GTA

This TPI is becoming very frustrating.

Steve89GTA

12.8 is fantastic. congrats.

five7kid

iTrader: (14)

It's not the standard $1250US shortblock. But, it's not the ZZ4, either. Sounds more like the L31 shortblock. Whatever it is, it's roller-lifter compatible.

There was a magazine article last year (in Popular Hot Rodding, I believe) about their developement of that engine. In a combo not unlike what you suggest, it made less than 300 gross flywheel HP. They had to go with the Hot Cam & 1.6 rockers to get to what the 350 HO makes out-of-the-box with a carb. If you want 300 RWHP, you're going to need more than the engine they're offering, even.

These are also not the off-the-shelf Vortec heads that everybody is all ga-ga over their low price. These are their performance upgrade heads, required to handle the extra lift.

You need to read some of the fine print, too. They produced those numbers with 1-7/8" primary headers (long tubes, to boot), 52mm TB, and Edelbrock runners. (BTW, u_host, the HP quotes are with a TPI set up as stated - not sure exactly what you meant by "TPI will kill power output on that motor". And, compression is 9.6:1 - I'm not sure what they did to get the extra half-point.)

If by "emissions", you mean you have to pass sniffer - no problem. All SDPC is saying is they haven't gone through certification of the combination. Unless your emissions station is **** about installed equipment, you won't have any problems at all with their engine passing sniffer.

But, to get even within a stone's throw of your stated goals, you're going to have to at least start with their engine combo, and add the TB/runner/headers to that. Along with PROM tuning. I'd still say the engine is a bargin, compared to what you're considering.

unknown_host

iTrader: (1)

$1250 is for the GM goodwrench long block. The L31 long blocks are closer to $2000.

Steve89GTA

Interesting. Thanks for your response. I just noticed the work done to the heads to accomodate the cam. Do the specs coincide the the lt4 hot cam?

I'll email them and get some more information. Wasn't the L31 block out of late model TBI trucks?

1 7/8 headers seem huge though. wtf. I think I'd like to see a real dyno of that engine strapped to a TPI before I'd shell out the mulla. I wonder what the low end is like with 1 7/8's.

five7kid

iTrader: (14)

You're right about the long block. I was mixing things up there.

http://www.sdpc2000.com/cart.asp?act...tart&catid=514

The L31 is $1500. Has PM rods, cast 13cc dished pistons. ZZ4 has steel crank and hypereutectic flat-top pistons.

The L98 has regular rods, 11cc dish pistons. So, maybe that is what they're using. Could account for the extra compression over the 330HP carb version (if it uses the "truck TBI" L31 - but with flat-tappet cam).

I don't recall what the torque curve looked like from the mag article. Notice, though, their stated HP and torque peaks are both 4200 RPMs. And, yes, that is the Hot Cam (not just close in specs).

I wouldn't worry too much about the low-end effect of 1-7/8" headers. That's a one-word solution - "stall".

Another thing to think about with the combo you were considering: You'll need "completion" items such as tin, gaskets, rockers, pushrods, lifters, etc. You'll either have to buy, or steal from your current engine (can't steal gaskets, though).

Steve89GTA

I'll be running a 5speed behind this motor. Regardless, having both peaks at 4200 is amazing!

Can this motor put me into the low 13's with 1 3/4 headers, 22 or 24 ib injectors and a custom chip

Spectre

I dont understand why they would put 1 7/8 headers on
a 350hp engine ??

The '02 chevy camaro GMMG ZL1 has 1 7/8, and puts out
600hp, and 575-lb-ft with the phase 3 427 race engine.








source:HOTROD october 2003

unknown_host

iTrader: (1)

Because it probably made another 7 peak horsepower and lost an average of 20 horsepower, but when people are buying an engine they look at peak numbers .

Steve89GTA

I agree with unknown. This motor would probably perform best with 1 5/8's or MAYBE 1 3/4 but I'd go with hooker 2055's if I were to get this motor.

five7kid

iTrader: (14)

Not for very long...

Steve89GTA

Have faith in thy world class. LOL