I'm trying to determine the largest displacement one can expect to achieve before having to move from a stock "appearing" TPI to some aftermarket solution, i.e., StealthRam. I want to build a large displacement TPI motor using aftermarket TPI components - runners, TB, base manifold - and I'm looking for advice from people who've already done it. I have several articles on 383 buildups, but I want to go 396/400/426. Objective: Smoking torque for street fun only. I don't have any desire to race beside the occasional ego popping street light joust (when it's safe to do so...). Your help/advise would be very much appreciated.

i think a few people have 406TPI setups.

If you are gonna use aftermarket TPI setup, i would go with a healthy 383 or 406 setup, and you will make tons of TQ

I always wanted to build a 383TPI, but the more i researched, the TPI runs out of breath pretty quickly in the power band. So i decided i would go with a carb setup for now, and save the money for an aftermarket setup like the stealth ram, or even better yet the miniram.

If you are looking for lots of bottom end TQ i think the aftermarket tpi setup is the way to go though.

good luck

I would look into a kit I bekieve PAW has. It uses the L98(350 block) with If i remeber a 3.995 stroke crank. Somewhere around 401.4 cu. in. There was an article in CHP I think. It had a limited power band of 5200 rpm's made like 480lb.ft. I wish i didn't throw out all my old mags. A 400 would be cool but would really starve above 4000. GM sells a steel crank 3.80in. for use in there 383. 4.00 in. bore and the 3.80 crank.

Do you recall about how long ago that article was printed? I've been a subscriber to CHP for a number of years so maybe I missed it.

I really want a powerful motor, strong emphasis on torque. I don't feel the need to spin the motor fast if it has that "GRUNT!"

Of course all that grunt will soon be the end of my T5 and then the BW 9 bolt too... but that means I have to install a T56 and new 12 bolt...

Your right, the T5 wont handle that much TQ, but I dont think you will break your 9 bolt, Miles at 9bolt.com is running a built 427 big block with his, and its still holding up fine.

I think a 406 TPI built for TQ would be awesome

I actually had a stock TPI setup on my 406 before I pulled the engine...

Actually it was a bone stock TPI setup with the exception of an Edelbrock base to bolt to the stock 400 heads.

The torque was pretty decent, but it ran out of breath a bit over 4000 rpm...

The stock TPI setup simply doesn't support enough airflow to make it a viable alternative. If you go with a heavily modded TPI setup (aftermarket runners, ported plenum, aftermarket base) then you have a lot more money invested than buying a stealth ram (or at least about the same, even finding the parts used)

That is why I bought a Stealth Ram...

I think it was about 2 years ago. Another viable option is buying the steel crank that GM uses in their 383 crank motor. Adding that with an adapter for the rear main seal on a 400 block boring it .030 over would give you somewhere around 412cu.in. This benefits you two ways. Since it is a 1 piece seal crank you don't need the 400 balancer nor a special flywheel. Go with a 6in. rod and decent flowing heads in the 195cc range and that'll give you a tq beast.

You are gonna need an edelbrock base,Hi-flo runners,TB, and poterd plenum to rev it anywhere past 4500.

motown makes a 427 small block

im goin for a 406 except im putting a ported lt1 intake on it...i can loose a few ft lbs to get it out of the hole without buring the tires off it...
if u want to go with tpi then defiently get an aftermarket base runners and very heavy porting on all the peices...


motown also is working on 454 Small block
...4.25 bore 4 inch stroke

(edit) 500 posts!!! wooohooo lol

sorry

arent motown blocks in the neighborhood of 4 or 5 grand? thats absurd!

Motown blocks also have a fair number of features to make huge displacements from small blocks. A raised cam, increase clearance for long rods and crank throws, thicker cylinder walls, relocated water jackets, etc. If you intend to build a large displacement small block (427, 454) you will need something like this. A 406 can be done with a relatively stock block.
matt

The aftermarket stuff alone won't cut it on the 406 IMO. I'd do heavy port work on all the pieces, siamesing the runner ends, plenum holes, and base entrances. You'll effectively cut off some amount of lowend torque but you'll still have quite a monster on your hands that will rev to around 5,000rpm... I hope you plan to do some suspension mods lest you snap your unibody frame in two!

FALCONER V-12
STANDARD PERFORMANCE PRODUCTION ENGINE
SUPPLEMENTAL FACT SHEET


WEIGHTS & MEASURES
- 600 CID
- 522 LBS.
- 4.125" BORE
- 3.750" STROKE
- 23.5" WIDE; 19.5" HIGH; 36.5" LONG
WIDTH FROM CRANKSHAFT CENTER LINE)
LENGTH TO FRONT ACCESSORY DRIVE PULLEY)
- ALUMINUM BLOCK & HEADS


PERFORMANCE
Running 92 Octane Unleaded Gas:
-650 HP AT 5200 RPM
-560 FT.LB. TORQUE AT 1500 RPM
-750 FT.LB. TORQUE AT 4500 RPM

PACKAGE
Each engine is dyno tested upon completion and
base price includes the following:
-ECU
-WET SUMP
-TWIN TUNED PORT ELECTRONIC INJECTION
-DIRECT FIRE IGNITIO
(This is what will be on my 3rd gen late summer-early winter)

Holy sweet jebis. how much does that beast run you? Whats the bolt pattern on it, will a regular transmission fit? Will it fit to stock motor mounts? "TWIN TUNED PORT ELECTRONIC INJECTION" whats that mean? Very purdy, but not somethin i think would work on a tight budget. congrats on that monster tho.
Matt

Motown blocks do not use the raised cam. They also are reasonably affordable, Summit has listings from about 1700-2300 dollars. Now that is not cheap, but when you consider the benefits and look at what is comparable from GMPP, it is untouchable. I want one. I think a nice 415-420 small block will fit nicely between the fenders of my Z-28. I have a 383 now and could use my internals with the Motown with some bigger slugs and make some serious power with a HSR or MiniRam.

No it's not in my car (that a vette) I am 95% sure I'll be getting it late this summer. As far as the motor mounts they mont right up just 8.8inc foward (I need to relocate a custom alumn. rad. forther into the nose) and it bolts up to a standard tranny (i'm going to be using a t-56 w/ .5 6th and a Fab Tec ford 9inc in the rear w/ if I can find some 3.02 in the rear w/ eaton carbon posi). It's going to be one heck of a project I'll have the car done about 6-9 months form the arrival of the V/12

SuperchargedRS

How much is that monster gonna set you back? Where do you get one? I am just curious.

anything over 350 ci dump the stock tpi and go w/the mini ram. i've had anything from a 305 w/a old zz2 gm cam stock tpi ( on a bet and it went 13.90 street tires 1.9 60 ft) to a 4++ci in my 89 formula 350. I like the curent combo though 4++ if your staying w/small cubes a lot can be done w/ tconverter a gear headers and cat back my .25

http://www.falconerengines.com , and for the price... I have saved up quite a bit. Lets just say for the price of that engine and drivetrain I could buy a 02 Camaro, none the less this is something I have been planning for about a year now and just about got the $ so I'll under the hood soon (knock on wood).

Thanks for the input. I truly appreciate it.

So whats the concenus?? If you want to keep a stock look under the bonnet, can a Ported Factory TPI setup flow enough for a 383 ???

In my opinion, a healthy 383 will always be starved for air with a factory TPI setup. This does not mean that it will not make power, it just will never be able to perform to its full potential. If you were to siamese port the base and port the he!! out of the runners and plenum, then you would help move some air. Add some aftermarket runners and a larger TB and more improvement would be had. A healthy 383 with TPI is a torque monster, bye bye tires!! I am sure that others will disagree, but this is based on my experience.

I would go with ported big base some big a$$ runners ( if you aren't going 4 huge hp ) and what i posted b4

406!!!!!!!!! There is no replacement for displacement. And you dont have to pay for machine work, a new crank, etc. Unless of course you wanna build the bottom end, and then the price is comprable, with even more cubes. Cant beat that. Just my 2c.
Matt

I would at least put in a aftermarket crank in a 406, I' cracked 3 stockers b4 I wised up. Now i have eagle rods je pistons and a forged crank oh ya 1 broken block.

Can a TPI unit keep up with a 383 to 5000rpm? Maybe with a 52mm throttle body?

nope not a stock one

Unless you port the snot out of it, no. In my application, I run out of steam at about 4500-5000 rpm. I have not siamesed the base, and my prom tuning is far from optimum. Plenty of people have no problem, from what I read here, winding out there motors to 6000 with extensive port work and proper calibration. It can be done, just takes some work.

Can I port my stock base? I have ported the plentum some and can go further with it. Right ow I have stock runners can they be siesamied?
Sorry if these are dumb questions.

Check out the Tech Article on siamese porting your base, that is not problem. As for you stock runner, you would need to weld some sheet metal over the top to allow you to siamese port them. SLP and AS&M make siamese runners worth looking into.

BTW the only dumb question is the one that goes unasked.

Thanks! Can the porting and siesamied runners give the TPI the air flow it needs? I think I am going to give it all a try and see what happens. I can always get a stealth ram if it don't.

never a dumb ? if you don't know the answer. yes port the snot out of your stuff. I ported my stock intake back in 91 when I first bought my 89 350 used slp runners but never siamiesed the base ( does turbulance become a prob? I don't know) I bought a set of big runner gaskets and ported the snot out of slp runners and matched the stock base and plenum. I went 12.70 108 mph w/street tires in92 I don't remember if any body had a big base then or not. yes I had more done at the time w/the car but I never had any prom work done and still don't just a stock 350 chip and 24* inj yes I'm way out of cal but I'm working on getting DFI. yes back in the day I saw my snapon scanner hit around 7,000 rpm but the car fell down about 5,500 or so the car will run w/stock but won't reach its potential P.S. mini ram 4.11 3500 nonlockup converter hooker supercomps

I'm going to try all the porting and siesaming I can and see what I can get out of it. The way I see it the runners are the biggest problem that I will have. Does any one know who makes runners that are already siesamied? Seams like I have seen some advertized some where.

SLP and Arizona Speed and Marine. I have the AS&M runners. They can be purchased through Thunder Racing which has an ad up at the top. THey ain't cheap though, I think they are overpriced, but I bought them anyway. Here you go did some homework for ya, AS&M from Thunder Racing=$475, SLPs from SLP=$260.

Some how I feel this is going to get expensive It looks like the Stealth ram is closer to reality than I thought.

Yeah, the TPI **** is expensive and nobody will argue that. However you can find deals on ebay or place like that. The HSR is almost to good to be true. Base manifolds are as well expensive. The Super Ram used to go for about a $1200 from Jegs. My TPIS base was $425. I think the HSR is where its at, price and hopefully performance.

look at the mike cres post on his 383, that should tell you some stuff.

I can't find mike cres post can you direct me to it? Thanks

I don't know about that post you are looking for but I can give you some price ideas for a 383 kit. I am sure better prices are available but this is what I have found. Scat cast steel crank=$270, Eagle H-Beam rods=$480, SRP forged pistons @$400. Now is not a kit, just prices from a company I have used many times before. It will give you an idea of what a 383 will cost for the bottom end. I think if you plan to spend more, you will be better off. Look around on the internet, there are so many companies selling good 383 long blocks and crate motors, you can get what you want on your budget. Just do the research.

you can run a stealth ram with a modified computer on a 383 with factory computer in an IROC couldn't you? or would you need Holley's ECM for the stealth ram?

Sure... you can use your computer.

I have been reading the post about porting and siesamied runners. I think this might work ok. I think I will order the SLP runners. The 383 kit that I am looking at is from strokermotor.com, has anyone had any experiance with them? One other question, is 650.00 a good price for a roller block fully prep'd and painted?

Yeah, I think 650 is a good price. I have seen people spend more for prepped blocks. Now, that is full machined and clearanced for the stroker application, right.

Yes fully clearanced and prep'd. Also includes stock roller lifters. The way I see it the lifters are $200.00 new so I am paying 450.00 for the block and all machine work.

So you decided against a 400 then? Any particular reason?
matt