91 zeee

For anyone interested, GM High Tech Performance magazine currently has an on going TPI 383 build. Nice to see the magazines are still interested in 3rd gens and TPI. Here is a link:

http://www.gmhightechperformance.com...0_project_car/

Johnny Blaze

iTrader: (15)

I read it. Can't wait to see the next issue! Seems pretty radical, curious to see what intake they put on it.

91 zeee

Me too. I'm glad they are keeping the TPI, can't wait to see what kind of numbers it puts down.

Johnny Blaze

iTrader: (15)

I'm expecting a mini ram or super ram intake.

IROCZ28dan

The current issue shows them using an edelbrock lower base and i think bbk runners, they are definitely sticking to TPI based intake...Unfortunately I think they are going to be disappointed with power output...

MoJoe

iTrader: (5)

Johnny, that 383 doesn't sound much/any more radical to anything on TGO where someone builds bigger than a 355. To me, the GMHTP engine specs seems like the biggest bang you can get, and still be compatible with TPI, emissions, reliability, "street driven", and a daily driver. IMHO Anything bigger, anything targeting high(er) HP, crosses into the "race car on the street" category.

FWIW, the Lunati Sledgehammer kit, at least for the 2 piece RMS, lists for $2400. Add heads ($1600), cam ($200), reuse stock lifters, rocker arms ($350), and you are $4550 into the engine just for major parts. Add misc parts,, intake work, and a tune...

Agreed: It will be interesting to what the other choices they make and the results. Can you accept a magazine's results as "real world", or cynically say: Advertiser's dream?

YMMV,
Joe

fozzi58

My planned build is basically outlined by this build. I caught it a couple months ago when the first installment came out but they are installing the Sledge into a 4 bolt main (pre 75?) block and getting the machine work for free. I'm looking at a bowtie block for $1800 and the Lunati rotating assembly I am seeing on Jegs/summit is for a 406cid to match the BT block and is listing for $3k+. Add a set of AFR complete heads for $2k, and if you want to spin it to 7k rpm then a lunati roller valve train & cam is another 1k.

SO I'm at $8k and I am saving money by porting the stock TPI unit because its going to break by budget to get a FIRST TPI (what I really wanted) and then add the turbo system. I'm leaving myself $5k to do trans, rear, suspension, and body work.

Sorry about the tangent.

Tuned Performance

iTrader: (92)

Edelbrock High-Flo Tpi runners and base and holley 58mm tb

fozzi58

:/ Meh

Was looking forward to seeing a TPIS big mouth TB on there. Then again it is supposed to be a budget build. Guess we (as subscribers) will wait and see.

Orr89RocZ

iTrader: (20)

Budget build yet lunati sledgehammer rotator??? You can do that build using basic cast crank stuff but if wanted forged, and thats always good, you can get stuff well under 2400$. Could get stuff for 1700-2000 easy

Tuned Performance

iTrader: (92)

That would be my last choice of intakes.

fozzi58

Aw damn. That's the new issue? Hope its in my mailbox when I get home.

@ Orr - I know. The mag touts a budget build 383 with a sledgehammer rotating assembly. I am not looking at my build as budget cause I want boost and more cubes but I want to see how they (GMHTP) justifies anbd lays it out.

Tuned Performance

iTrader: (92)

yes, Im not sure when it showed I found it on the kitchen table this morning my wife covered it with papers lol

vetteoz

iTrader: (13)

http://xtremecarzone.com.au/index.php?showtopic=386


Their " extremely affordable" comment is fine when your advertisers are giving you parts
As you say
http://www.summitracing.com/parts/sc...make/chevrolet

ProZZac

Should look something like this

RaverRacerX

not a very radical setup. the 230/236 duration will be eaten up by the extra 28ci. should make decent power though.. i wouldve done an XE-R lobe for it considering where peak flow is on those heads and to make a little more torque and power in a more drivable way. maybe some sort of split to crutch the intake.

has anyone even played with the LSx lobes on street SBC engines?

prozzac, very nice.

Orr89RocZ

iTrader: (20)

Some of those ls lobes have less lift than some of the high lift sbc lobes using same rocker. Ls uses 1.7's so their cams look big. My turbo sbc uses a 1.6 rocker and still has .640" lift. Not many ls cams make .640" with 1.7's let alone 1.6. Xfi stuff is good just harder on valvetrain and harder to control at high rpms. Really need lsx style light valves, titanium retainers and very stiff springs. My car doesnt have light valves but all the other goods and i hope i can spin high enough to use the cam and have stability

With tpi being low rpm, xfi will be fine. Still use good valvetrain but not having to turn rpm will help keep things stable. No reason to go any more aggressive and sacrifice spring life imo. This build should be torquey. Down on hp since manifold and runners are not ported to feed those heads and cubes but capability is there

fozzi58

If I go with the ported bare heads (prolly 210), I was contemplating the beehive springs, titanium retainers, and those other something-filled (sodium filled?) vales that are super light. The Lunati roller lifters are good to 7000+ rpm. I planned on being safe and keeping to a 6600 redline pending the dyno tune. I still need to find a cam that supports some decent torque down low and the RPM range I want. Peak HP isn't really a goal, but I do want a broad power curve that is strong through a larger RPM ranges than having an extra 40 hp for a shorter time and sacrifice power across the curve.

Finding a cam to do this is my challenge.

Orr89RocZ

iTrader: (20)

Pac springs has a few beehives to consider but i like double springs.

Call Mike Jones of jonescams.com. He will give you what you want.

fozzi58

Don't the double springs have a pressure limit like 325lbs? I read that the beehives can get to 500lbs and when your revving close to 7k, it tends to cause valve float with weaker springs.

I'm still learning a lot while I prep for my purchases but I will keep jonescams in my collection. Thanks.

Orr89RocZ

iTrader: (20)

Beehives typically have less pressures but the design is less susceptible to frequency vibrations which can cause float and bounce. Diameter and coil thickness all play a part in determining what frequency a spring will vibrate and lose control. Beehives have a conical variable diameter so their frequencies are just about eliminated from concern, so they can use less pressure. Plus the shape has reduced weight which also helps in that it can use less pressure.
Double springs can come in just about any pressure you want. 600-1000 lbs open. For hyd rollers, non billet cam cores with stock type lifters you may not wish to run much over 350-375 lbs open pressure. If you get aggressive with hyd rollers you may need special lifters like Morels and others that can handle high spring pressures. 500-550 may be doable at that level but need billet cam core.

Your average aggressive shelf grind typically will be ok at 140-160 lbs seat pressure with open pressures around 375-415. Typically wont need to go higher unless real heavy valvetrain. There are guys doin near 8000 rpm on hyd rollers in race apps, i have seen light lsx stuff spin 7600 alot with milder cam lobes and basic 400 lb open double springs. So it can be done.
My big cam should work with 180 lbs seat/450 lbs open doubles but havent tested it yet. Had valvetrain issues last year but on low boost it was able to hit 6500 before seeming to float due to my guidewear issue from geometry issues

91 zeee

I know this thread is old, but that's a clean motor. what are the specs and how does it run?

Tuned Performance

iTrader: (92)

banksGTA

iTrader: (3)

I know its an old thread but i was wondering if anyone knew what happened with this project? Maybe someone with connections? Thanks

TTOP350

iTrader: (8)

GMEFI on facebook is where they have kept going.

MoJoe

iTrader: (5)

The articles have ended up on the SuperChevy site. Here are a couple articles. I couldn't find the "it's done" article..

1987-firebird-formula-350-project-car
how-to-build-a-383-small-block-engine-sledgehammer
383-small-block-lethal-weapon-project-anxious-for-more
383-small-block-lethal-weapon-project-top-gun

banksGTA

iTrader: (3)

Yeah, those are the same articles that was in the magazine before they stopped printing it. I was just wondering if someone had an inside contact to see if it ever was finished.

Nelz

http://www.hotrod.com/features/1602-...pr=16240699522

The results were somewhat disappointing. 384HP @ 5800 RPM and 454 ft. lbs @ 3200. I emailed Greg at anti-venom and he said that they had trouble getting the Edelbrock runners to seal up without vacuum leaks so they ran the motor with the stock runners (which you can see in the last photo.) That's why the HP number was down.

I would expect those heads, cam and headers to make more HP than what it did, but the stock runners seem to bottleneck the combo. Bet if they switched to ASM runners, or anything like that it would unlock more.