building an engine, need (expert) opinions

[STEBS]

Ok, heres the low down... Ive got a build plan for the 400 im gna buy in a couple wks and not sure how i want to procede frm there once i get it...

First off, id like to put the tbi set up so that it has a factory appearance so to speak
Second off, although i know that you basicly "pay for power" im just not sure as to what point i should call it good enough for what im wanting (hence getting opinions)

What im getting is a mild 400 (stock bottom end, cam, performer intake, headers, etc) and my plan is to ditch the heads and intake, run a stock 350 tbi topend (heads and intake) with a 454 throttle body, probly comp cams 12-338-4 computor friendly cam, new valvetrain from lifters to 1.5 stamped steel roller tiped rockers, valve springs, shooting for 9.3/9.5:1 comp ratio, headers, 2.5" duals goin back, ditching the clutch fan for an electric set up, and complete tune up... also talked to a guy at pcm performance that said hed burn me a chip without needing my ecm fer 175 (not to sure on that part weather i should trust them or not)

Been doin alot of reading up on various forums (including devs post here @ gmt) bout the technical side of creating a "powerfull tbi" and i want a set up that im happy with, but at the same time, dont want to spend a fortune into an engine... So heres were the opinions come into play

Keep the set up on tge 400 now and just get a tbi adaptor for the intake?
Vortec heads w/ tbi intake?
Stock tbi heads and intake?
Tbi heads and performer tbi intake?
Aftermarket heads and intake?

Do i need to do any mods to the 454 tb?
Can someone elaborate on the "splicing of the tps/iac wires" on th 454 tb?
I figure ill need a better fuel pump, with the options in devs post, is the opporating psi high enough that i need an inline regulator with bypass before the tb?
What kind of fuel pressure woukd i need to look for with this set up?

How respectable is this mild combo gna be?

The trucks intention is a daily driver/ wkend wheeler/ take it on trips to see my parents in new mexico... Is my build headed the right way, or do i need to make some other build plans?

Im really hopin dev chimes in, as his sticky was probly the most ive learned in years about sbc, but looking foward some some good feedback frm every1

 

[jdyates]

If you're going to build an engine, go with Vortec heads. One of the big reasons TBIs aren't beasts from factory is because the heads SUCK.

 

[TylerZ281500]

your planning a complete rebuild correct?

vortec headsare even a bit small for a 400. first off take that engine into get magnafluxed and snoic checked etc 400's are crack monsters or some have weak castings etc. so get that all checked out first. use aftermarket heads and intake, link to the cam being used? 1.5 or 1.6 rollers will depend on what cam is used etc.

if your getting a custom chip id go straight to tbichips.com. your cam cant be too big though because your computer will not like it very much.

exhaust just stick with 3" on a mild built 350 you can do 3" so on a 400 mildly built well thatd be right up its alley to get it exhaling good , headers.... yes, 9.5 comp max? id bump your compression up to at least 10:1 or close to that so your utilizing some power, im hoping you arent gonna start complaining that you want to have good gas mileage next because you wont probably ever.

for fuel idr what psi 454 use but id use a stock gm pump something from an lt1 is what i use, pressure regulator inline and forget about the whole pressure pod area, just gut that, or remove it if you can. id use the 90lb/hr 454 injectors just so you know you have room to grow.

if i may speak my mind, tbi stock anything sucks so scratch any of that off your mind, as for keeping fuel injection yes its great but your limiting yourself a bit with a stock chip. a 400 can accept a much larger cam than a 350 can and the computer as well.

looking up that cam i dont see anything about computer friendly, i also dont think your computer can handle that, maybe a 454 chip will but then again thats alot to figure out. your better off going with a carb setup or doing some sort of multiport setup or aftermarket injection. your sorta limiting yourself on what you can do with what youve mentioned.

alot of people overlook transmissions and rear ends and such, if you have alot more power your gona need to beef up your trans, rear end etc. with a larger cam youll need a stall converter if you have an automatic.

i havent looked at the powerful tbi section in a while but my guess is you cant rely on it much. 400 is an animal of its own in every form, comparable to a bbc in sbc form? maybe but not really, like i said completely different. ive seen many great fuel injected setups with 400 both naturally aspirated and with PA's so im not saying this cant be done, it just seems like you want to spend the least that you want to while maintaining a stock appearance when no one has to peek under your hood. saving cash and skimping can hurt the engine in the long run.

electric fan swap is a good idea, not necessary but a nice addition for sure, once again i used my lt1 fans with a jegs dual fan kit, i have the primary fan switched through the ignition and the secondary has a break in it as an ovverride on a manual switch.

also that cam isnt computer firendly, you cant use a roller cam without a retrofit, is you plan on using newer heads youll have to drill the steamholes on the 400 block.

 

[STEBS]

your planning a complete rebuild correct?

vortec headsare even a bit small for a 400. first off take that engine into get magnafluxed and snoic checked etc 400's are crack monsters or some have weak castings etc. so get that all checked out first. use aftermarket heads and intake, link to the cam being used? 1.5 or 1.6 rollers will depend on what cam is used etc.

if your getting a custom chip id go straight to tbichips.com. your cam cant be too big though because your computer will not like it very much.

exhaust just stick with 3" on a mild built 350 you can do 3" so on a 400 mildly built well thatd be right up its alley to get it exhaling good , headers.... yes, 9.5 comp max? id bump your compression up to at least 10:1 or close to that so your utilizing some power, im hoping you arent gonna start complaining that you want to have good gas mileage next because you wont probably ever.

for fuel idr what psi 454 use but id use a stock gm pump something from an lt1 is what i use, pressure regulator inline and forget about the whole pressure pod area, just gut that, or remove it if you can. id use the 90lb/hr 454 injectors just so you know you have room to grow.

if i may speak my mind, tbi stock anything sucks so scratch any of that off your mind, as for keeping fuel injection yes its great but your limiting yourself a bit with a stock chip. a 400 can accept a much larger cam than a 350 can and the computer as well.

looking up that cam i dont see anything about computer friendly, i also dont think your computer can handle that, maybe a 454 chip will but then again thats alot to figure out. your better off going with a carb setup or doing some sort of multiport setup or aftermarket injection. your sorta limiting yourself on what you can do with what youve mentioned.

alot of people overlook transmissions and rear ends and such, if you have alot more power your gona need to beef up your trans, rear end etc. with a larger cam youll need a stall converter if you have an automatic.

i havent looked at the powerful tbi section in a while but my guess is you cant rely on it much. 400 is an animal of its own in every form, comparable to a bbc in sbc form? maybe but not really, like i said completely different. ive seen many great fuel injected setups with 400 both naturally aspirated and with PA's so im not saying this cant be done, it just seems like you want to spend the least that you want to while maintaining a stock appearance when no one has to peek under your hood. saving cash and skimping can hurt the engine in the long run.

electric fan swap is a good idea, not necessary but a nice addition for sure, once again i used my lt1 fans with a jegs dual fan kit, i have the primary fan switched through the ignition and the secondary has a break in it as an ovverride on a manual switch.

also that cam isnt computer firendly, you cant use a roller cam without a retrofit, is you plan on using newer heads youll have to drill the steamholes on the 400 block.

I wasnt planning to rebuild it just yet (its still in the pickup of the guy im buying from and supposed to be a strong engine on a not brand new, but not that old of a rebuild) now on down the line ill look at goin through it top to bottom... Nvr heard of 400's bein famous for cracks, but ill deff get that checked out

Ill have to double check the cam numbers cuz that was frm memory (guy at jegs recomended it cuz its supposed to go with my comp and be just a lil bigger than stock) i remember the descricption said it was specificly for tbi/tpi

Im not too worried about fuel miliage, although itd be nice to still be mid to upper teens (although im not holding my breath lol)

Im only sticking with the tbi set up, cuz i do like the factory look, im in the works of a solid axle swap with the intention of making it look like it rolled outa gm assembly plant with a solid front axle

As for the trans, no auto matic thank god... But i do have the puny nv3500 5speed, wich im getting a 4500 to stick behind the 400

Is ther any peticular head u had in mind?

I love the idea of the elec fans too, not just for freeing up a little power draw, but to me it just makes the engine bay look SO much cleaner... I already got a set of fans from a tourus, just need the harness kit to get em runnin

 

[STEBS]

Forgot to mention... Another reason i had the tbi idea in mind (cuz when i had the offer to buy this 400 that im buyin, instantly hit the forums seeing if others had ran a 400tbi) ive seen quite a few build threads of ppl doin runnin tbi set ups and lovin the lowend torque... Granted idk what theyre set ups are, but ive seen quite a few 400tbi's on various forums

Frm what i have read up, its basicly a stock (or bored) 400, stock tbi heads/intake and 454 injectors in a 350 throttle body (kinda odd cosidering the cfm of a 350 is minimal), cam and chip... thats what every1 seems to be runnin (or close to) and i gotta wonder just how efficient the set up is

 

[TylerZ281500]

Details on that engine would be great before hand. After.arket would be best you can try to get away with vortecs and a really nice port polish and angle jib buy I never had luck with them. I've dine both a 400 and 383 tbi before swapping to carb. The 400 was a pain way to much cam head everything for a tbi computer. The 383 I had maxxed out but was able to time it just fine. I ran through 3 400 bli ks before finding a useable one. I'd do your rebuild now if it were me. Its dumb to waste time and money to only pull it back out and waste money on new gaskets when bearing are so cheap and just extra insurance.of those are stock heads you may have to drill the steamports to accept newer heads tbi amd tpi are very different as well's saying a cam is for both may not be the case it may be good for one and ok for the other but probably not both. Tpi can be coersed tuning wise differently than tbi
for fuelmileage you'll probably get single digits no offense

 

[axisT6]

Check to make sure that 400 block is the "509" block. Those are 2 bolt main blocks with a high nickel content in the casting and do not have the issues with cracking in the web area that the 4 bolt mains do.

Take a hard look at the cam that is in that engine. This is what you really want to get right. Since this a big inch small block, you can get away with a slightly bigger cam. Call any reputable cam company and tell them what you are doing. They should be able to get you what you need. You will probably end up with a 225/230, 230/230, 230/236 duration (@ 0.050") with lift anywhere from 0.450" - 0.480" with a LSA from 112-114. Again, make some calls.

As for heads, toss the factory ones. To keep things budget friendly, look at vortecs, World SR Torquers, and Dart Iron Eagle. Do not go with an intake port larger than 200cc.

In order to feed thing, talk to Sean at TBIparts.com. He can set you up with a fully rebuilt and bored 454 TBI with the injectors you need and the IAC adapter harness you need. He will also take your current throttle body and give you credit. You will need a better intake also. I have heard good things about the holley pro-jection intake, and any decent carbed dual plane will work.

You will be fine with fuel pressure around 30 psi. Do what Tyler said and use an inline pressure regulator. Sean at TBIparts can set your throttle body up accordingly.

As for the tune, I will say that you will never get an optimal tune from a distance (mail order). The best way to tune your truck is to do a street tune, or tune on the dyno. At this point it may be worth while to start learning how to burn your own chips. Since your truck is a 92, go to dynamicefi.com and check out the EBL.

If you do this right, you will have strong, dependable engine that makes tons of torque and gets good mileage.

I am starting the process of putting a 406 in my truck so I have been down this road.

 

[TylerZ281500]

axis..wil vortecs really work? i had trouble using them even with a carb and the cam was around 520 lift 110 lsa and 240 duration or something. i know a port and polish job will certainly help but just thought to stay clear of them as they were very problematic for the two engines ive built

 

[axisT6]

Vortecs have their issues. Factroy take-offs cannot tolerate a high valve lift without work. These have press-in rocker studs that should be replaced with screw in. I should have said aftermarket vortec heads as those don't have the same issues IIRC.

Overall I have seen good results with vortecs, even on a 406. You have to keep the cam conservative though. Example, the vortec headed 406 I just mentioned had a cam with the following specs: 230/230 @ 0.050", something around 0.450" lift, 114 LSA with 1.5 rockers and made over 400 HP/500 TQ. That cam is relatively mild on a 406 and worked well with the vortec heads despite having 170cc intakes.

 

[STEBS]

Vortecs have their issues. Factroy take-offs cannot tolerate a high valve lift without work. These have press-in rocker studs that should be replaced with screw in. I should have said aftermarket vortec heads as those don't have the same issues IIRC.

Overall I have seen good results with vortecs, even on a 406. You have to keep the cam conservative though. Example, the vortec headed 406 I just mentioned had a cam with the following specs: 230/230 @ 0.050", something around 0.450" lift, 114 LSA with 1.5 rockers and made over 400 HP/500 TQ. That cam is relatively mild on a 406 and worked well with the vortec heads despite having 170cc intakes.

loving the feedback from everybody, very helpfull so far

did a little more research, the cam that jegs recomended for my setup is comp cams #249-12-388-4 .425/.440 lift, 252/260 dur, 112 lobe sep.

i will definatly talk to the tbi place u mentioned bout the throttle body and regulator

will factory vortec take offs work with the cam mentioned above? i was planning on new single wound spings that match the cam, aswell as lifters, rods, roller tip rockers, keeper, etc...

i was looking at the holley 950, but im thinking i owuld have to run a tbi adaptor for this intake correct?