neworlenes

I wanted to know if my tpi from my 307 in my trans am would bolt on to a 400 small block. I think im getting GM Fast Burn heads but i wasnt sure if everything would bolt up. What do I need to do or get for it to fit??

ANDYZ28

I believe this topic has been "discussed-to-death". Basically the TPI setup cannot flow enough air to supply a 406, and it (stock) can barely flow enough for a 350.

But it can be done.

neworlenes

Yeah sorry for probibly more repeated questions. However maybe someone can just point me to the best threds or places to get the best info of what works best and why. I have found myself running around in circles in some of these tech boards and stuff. I really just wanted to know what would work best as far as putting the TPI on my 400. Do i need a better ram air thing or something?

ANDYZ28

The stock TPI setup was designed to optimize the low end torque potential of the 5.0 engine. When it was installed on the 5.7 engine (which naturally flows more air) it worked great, except that the engine began to run out of power as RPM increased into the 4,500- 5,000 range. The installation of the stock setup on a 6.6 liter (406 cu in) engine will only make this much worse.

The 406 engine does not need a TPI setup because it already has "Gobs" of torque simply due to its' displacement, and to use an old analogy; "there is no replacement for displacement".

When I built my 406 I used a proven induction system, Vortec cyl heads, Edelbrock Performer intake, Edelbrock 750 carb. I plan on upgrading to an aftermarket EFI system sometime this year. I more or less copied the engine that Chevy High Performance built (The Impersonator) http://chevyhiperformance.com/techar.../148_0306_406/

I hope this is helpful info, Andy

BadSS

I'm not that familiar with the Fastburn heads. I'm sure someone will correct me if I'm wrong, but I believe there will be port alignment issues with a stock TPI intake. I'm not sure if the ports on the stock intake can me "corrected" enough to work or not. If that is the case, you'll need the Scoggins Vortec TPI base to run the rest of the TPI system.

TPI will work on the 406 but depending on your desired results and the heads and cam you run,,,, it may or may not get you where you want to be.

If you have to buy a new base,,, and since you would need a set of aftermarket runners for a 406 with decent heads as well,,,, considering the bang for the buck, I'd suggest going with the Vortec StealthRam intake. You'll still have plenty of bottom end power with the 406 and typically it's a lot easier to get a 406 with decent heads to run good numbers with a short runner intake than it is with the longer runners.

Shagwell

- stock/modded LTR just ain't gonna feed a 406.

305sbc

iTrader: (3)

The Holley Stealth Ram intake manifold would be a much better match for an engine that size.
30 lb injectors would get you in the ballpark.
Exhaust headers will need to be the 1.75" primary size.

I would consider 180cc intake port volume, and 68cc combustion chamber volume to be the MINIMUM numbers to go for when picking a head.

joenycfbody

I was also considering this swap.. I have a 406 shortblock, and an 88 305 TPI motor.. I was going to swap over the TPI & serpentine stuff over to the 406...

What is the main problem with the TPI system, when considering running it on this size of a motor?? What areas would need improvement..?? I was also going to use the 305 heads, b/c I believe they are 58cc chambers and would bump my C/R to about 10:1 or so with my dished pistons.. What are the ports on the 305 heads..?? 160cc??

(sorry, dont mean to hijack thread)

305sbc

iTrader: (3)

I mentioned above that another intake manifold and a set of larger injectors would match a 400 cube engine.

The 305 heads are valved too small to supply a 400 cube engine.

Putting stock 305 gear on a 400 would result in a very large vacuum being pulled at WOT. This is like driving with the throttle partially closed, and will cost you a ton of power. The higher the RPM the more power it costs.

It will work fine for idle and light cruising/towing, just not racing.

ANDYZ28

I am running Vortec heads with stock ports on my 406. These heads have been dyno tested on a 406 by Chevy High Performance Magazine with good results.

joenycfbody

how about if you were to do some port work on the heads, and increase to 1.94/1.6 valves??

GOY

SuperRam will give you the best overall package IMO.

There are many 11 second N/A SuperRam 406-420's out there. Just make sure your air intake leading up the the SR if in the 3-4 inch diameter range, and the heads need to be a serious concern (270's+ CFM intake - even 300CFM is not too much!)

Putting a TPI on it would be a waste of time and money - unless you used SLP runners that were 90% siamesed.

Shagwell

305 head won't feed a stock 350. Don't waste your time. All the porting you could do would just feed a mild 350. So putting them on a 400... - Its an old myth of putting 305 heads on a bigger small blocks to bump power. Yes, the chamber is smaller, so you up compression, but all the compression in the world won't help if you can't get enough in the cylinder. - If you had decent heads, you could port the TPI intake out for all that its worth and it would run ok, at best. Not a bad place to start, but not enough. Get a good set of heads and grind the crap outta that intake and get it running. Then start setting aside the dough for a HSR/SuperRam. -

- Heads make your HP, all the cubic inches in the world won't build any power if you can't feed it. It would suck to put a 400 in and get spanked by a mild modded 305....

BadSS

Not everyone has the cash at hand to buy good heads and another intake. If cash is limited,, there's no reason not to bolt the 305 heads and the TPI intake on the 406. It'll run better a lot better than the 305 and better than the stock 350TPIs. Port the stock TPI intake (at least grind the lip at the entry) and grind the EGR wall down in the plenum. Go ahead and get a good exhaust system for it (at least 1 5/8" long tubes) and a single pattern cam in the 225 degree range on a 110 spread and install the intake on 112 degrees (2 degrees retarded). The long small runners of the intake and the small volume low flow heads are not going to let it rev very high, but so what if you have to shift at 4600rpm as long as it is faster than what you had?

crazycrocket

Well here is something that has been done, transfer everything over to the 400 (get better injectors) then don't use the TPI intake, instead get a single plane manifold, install injectors in it, build a air tight box to mount on top of it and use your TPI throttle body. Then shorten your throttle and your kickdown cable.

Shagwell

stonedchihuahua -
good idea, but then for the time/money, HSR might be easier. - I'm a DIY guy myself, but its not for everyone. - As for the heads, you can pick up a set of vortecs at a junkyard for $200. Yeah, they'll need some work, but so will re-doing stock 305 heads. Then atleast you've got something w/ some potential, and if you can't afford 2 beans on some heads, the how do you intend upon building a decent 400 bottom end? - not trying to bash anyone, I've worked on a MAJOR budget for my whole life(only 22...). If I couldn't afford it, then I just saved until I could.

"...Speed costs...how fast can you afford to go?"

joenycfbody

I have a set of vortecs I was going to use on the 406.. but decided I wanted the TPI.. I would still use them, but dont know if dropping $450 on the proper intake would really be worth it..

BLUETA

I built a 406, TPI with a small cam as my daily driver. I use 4500
rpm as max, and cammed accordingly. I took a big curve last fall
at 65 in drive, hit the throttle, and the rear end stepped out a bit.
I get 20.5 mpg at 60, and at 75-80 with the air on, I get 19. I drove
1400 miles round trip to the Woodward Avenue Dream Cruise last
August, and got 17.5 mpg for the whole trip. If you want lots of power,
you will need good heads and more than TPI on the intake. But
for a big torque motor and fun on the street, the TPI and a
small cam work fine. Keeping the stock converter does put strain
on the drive line. I broke several tranny mounts as the 1-2 shift
was pretty hard. Even the 2-3 shift at 60 would bang the passengers
head back against the headrest. I switched to a 2200 stahl and
it's a lot better. Just decide on what you want and build accordingly.

joenycfbody

BlueTA, I sent you a PM on your heads & cam combo..

Shagwell

- several people bash for this, BUT... I've got 2 vortec headed TPI motors running w/ stock TPI intakes. I run either double(glued together) or thich(fel-pro 1266) intake gaskets to raise the intake to achieve proper port height, then drill & tap the heads to accept the conventional intake bolt-pattern. You'll also have to put bolts in the vortec bolt holes, simply use washers and Voila! - I have not had any vac/leak issues with either set-up. not neccessarily the proper way, but it works(even the runner height) and saves a lot of $...

wulff

If I was to give you guys a ride in my Monte I think you would agree that the TPI is working and working GREAT! For my heads and cam it works great, I am through making horsepower under 5000 but that is enough!
Mis-information is a bad thing.... In the 1970's I was one of the few people that had high performance 400 SBC's.. these were RARE on anything but a tow vehicle... now because of magazine articles they are the best thing since sliced bread and drove the prices sky high!! I could pick up a running 400 for $100 but when the 383 articles came out the price for even the stock cast crank went sky high.
Most people are "directed" by trends set forth by magazine articles.
How many people that say the TPI is too small for even a 350 has ever had one in a 400? And if you did, did you know how to set it up correctly? I have been at this game since the 1970's and I am surprised at the amount of 'experts' I read about that know-it-all and steer people away from good sound practicle performance ideas..
I know I can do some work to make it breath in the higher rpm ranges but when I beat my friends LS1 RAM AIR Firebird by 2 cars he said he was convinced and wants to do the same to his project car (a 1981 LS Monte Carlo with a 406).
OKay, some of you are chomping at the bit ready to tell me the parts I am using isn't a performance setup but unless you have been through the 1/4 mile with me you wouldn't have your minds changed anyway... Okay let the flaming
start , but I won't be able to read your posts for a long while since I will be in Mexico on business for several months.. sorry,

joenycfbody

Would you mind giving me some info on your TPI 406 combo?? Would really appreciate it.. What heads/cam/.injectors,etc.. You can email me if you want and we can talk through email..

Joe

87TPI350KID

400 + TPI = Less than 320 hp but 550 + lb ft tq

joenycfbody

thats good enough for me..

although i dont know how you come up with that much torque.. in EA 3.2, with my 406, milled 882s to get 72cc, 9.5 c/r,tpi w/48mm vette tb, 1 5/8 x 34" longtubes w/exhaust, and a comp cams nx268, i get 400ftlb max @ 3500rpm.. but the curve is preety flat from 2500 - 4800rpm.. thats @ 1500ft above sea level on 93oct also..

Shagwell

joenycfbody - you were only seeing 400 ftlbs? I'm guessing no TPI? -also, 882's suck! all the compression in the world doesn't help a poor runner. 993's are better for open chamber heads, but they still suck. W/o changing anything else in my combination I picked up a full seconfd in the quarter going from the most ported out, baddest set of 993 you can lay your hands on to my Toplines. - Super Chevy mag had a supplement one time w/ about 10 different sbc builds. They set up a aluminim headed 406, dropped on a Arizona Speed TPi set-up and had over 500ftlbs from about 2k on up!

I don't bash the TPI on a 400. Especially a TPI w/ all the aftermarket intake pieces... I just really recommend a decent set of heads. - No problem making good power w/ a LTR TPI, just that you could make more power w/ a better intake.

joenycfbody

shagwell - thanks for your input.. i am pretty much set on using the tpi setup on my 406.. the #'s i got from EA was with tpi inputted...

it was 400ftlbs @ 320-330'ish hp peak #s..

i used the nitrous cam b.c it was the only one with a wide lsa and a nice split pattern...

i will look into arizona speed.. heard a few good thngs about them..

as far as the heads, i just dont have the coin for a set of aluminum aftermarket heads...
i have the 882s.. i have 081s..and i have vortecs.. i would use the vortecs if the intake wasnt so damn expensive...

worst case, i just use what i got an upgrade it when i do get the money.. but i am keeping an eye out for a used set of alum. l98 heads..
was also considering a set of s/r torquers w/the late model bolt pattern.. even though they arent aluminum..but they are cheaper..

cali92RS

I think you need to break out the slide rule...
Check madmax's results...you know 330 horsepower to the wheels, with a 350 and stock runners.
This whole thread is what I was talking about. People perpetuating myth with no proof.

D's89IROCZ

I now a guy who kept the stock TPI on a 383 . Had a little cam and it made 400 rwtq but only 270 rwhp . This was with AFR 72 cc 195's . THE TPI KILLS BREATHING . His graph made power to 4600 rpm on a 383 ...... I am pretty sure it would be less then that ona 400+ ci.


There , does that help you see TPI and bigger cubes don't go together well ? He had heads , so nothnig left to choke it but the TPI.

Either way it won't blow up or anything... sotry it out and learn the hard way . But heck you may even like it who knows .

Shagwell

If you have vortecs, run 'em. drill/tap the heads, run thick gaskets and enjoy!

joenycfbody

D's89IROCZ - 400rwtq for me would be pretty damn nice.. I think i have stated, I am putting this combo together for a daily driver.. Not a strip car.. Thats whay I the lack of upper rpm power really isnt a concern to me.. I will be running a 700r4 & 3.42 rear, so even at 80mph on the highway, my rpms wont be more than 3k..

So it is the torque I am more concerned with...

shagwell - I will have to put the vortec side by side with the TPI base intake an see if I can use them.. The 4 bolts when you use a vortec intake, go straight down I believe, not at an angle like the standard intake.. The two middle holes, like you said, I can just drill an tap at the proper angle.. 72* i believe. no big deal.. Its getting the front & rear bolts to lineup..

Guess thats something I can do this week.. See if I can get the two to work.. If They will, then I will try doubling up on the gaskets and see what happens.

Shagwell

you don't line any of the bolts up, you drill and tap them all. - the vortec intake bolt holes are above standard sbc intake bolt holes. You have to drill and tap them all. I run the thick gaskets to raise the intake so that it is level w/ the top of the head port. I've also run 2 sets of stock gaskets glued together. - Put head gaskets on a block and set the heads on, snug 2 bolts in each head. Then set the gaskets on, set the intake on, drop a distributor in(to center the intake) and slide the gaskets to line them up correctly w/ the bolt holes. Then center-punch the heads. Then take 'em off and drill and tap.
Many people say it won't work, or say I'll have vaccum leaks, or that the port alignment sucks...I say sssshhhhh don't tell it that...cause it doesn't seem to know...- I've done 3 now...I'm about to do another set, so I'll take pics of my process.

joenycfbody

Cool.. Thanks alot for the detailed info.. Pics would be great.. Feel free to email them to me.. speedaddict02@nastyz28.com
Appreciate all your help.. If this works out, I would be real happy then I can ditch the 882s.. lol

joenycfbody

at what angle do you drill the hole?? Straight down i believe, correct?? Do you use a special type of vise or something to hold the head in position??