What's new
CK5
Register an account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members.

400 sbc???? (All assembled)

I wouldn't recomend the L31 injection. By the time you upgrade the injection spider, and modify the throttlebody to flow enough cfm, and still have limited performance, you would be better off with an aftermarket injection.

We tried a modified TPI on my son's 400, but we could never get a chip that would run right. Finally gave up after 10 or so chips and went wiht a carb. I'm sure a TPI could be made to run right, but those are still limited powerwise on a 400.

gotblazers said:
Well i figured i'd use the vortec heads and intake off a Vortec 350 since the Vortec motors are full EFI i figured i'd use their wiring harness and modify the ECM to accept the completely different motor its going on. Not exactly sure how it would work but thats why im posting here :dunno::popcorn:
Click to expand...
 
gotblazers said:
Well i figured i'd use the vortec heads and intake off a Vortec 350 since the Vortec motors are full EFI i figured i'd use their wiring harness and modify the ECM to accept the completely different motor its going on. Not exactly sure how it would work but thats why im posting here :dunno::popcorn:
Click to expand...

So are you wanting to convert a 96-00 vortec engine into your blazer and make it a 400?

!
And what kind of racing do you want to do?

Maybe start a. New thread with you specific questions
 
Captainfab said:
I wouldn't recomend the L31 injection. By the time you upgrade the injection spider, and modify the throttlebody to flow enough cfm, and still have limited performance, you would be better off with an aftermarket injection.

We tried a modified TPI on my son's 400, but we could never get a chip that would run right. Finally gave up after 10 or so chips and went wiht a carb. I'm sure a TPI could be made to run right, but those are still limited powerwise on a 400.
Click to expand...

We had luck with a hypertech chip and 454 injectors on a tbi 400. I don't have all the details but it was a customers K5.
 
38377k5 said:
Have you thought about a take out 6.0L?
Click to expand...
Your referring to the LS2? I've put alot of thought into those and have pretty much decided against it for a few reasons.
1.Inital cost is very high and i still need to modify it to get the power i want which cost even more.
2.Maximum torque/hp are at way too high of a rpm for my liking.
3.At a quick look of the 2 It seems to me that the LS2 is a much more complicated system.

Captainfab said:
I wouldn't recomend the L31 injection. By the time you upgrade the injection spider, and modify the throttlebody to flow enough cfm, and still have limited performance, you would be better off with an aftermarket injection.

We tried a modified TPI on my son's 400, but we could never get a chip that would run right. Finally gave up after 10 or so chips and went wiht a carb. I'm sure a TPI could be made to run right, but those are still limited powerwise on a 400.
Click to expand...
So what aftermarket injection set up would you recommend to make this work. I've looked at a few in the past and they are always priced at what seems IMO to be outrageous

63chevyll said:
So are you wanting to convert a 96-00 vortec engine into your blazer and make it a 400?

!
And what kind of racing do you want to do?

Maybe start a. New thread with you specific questions
Click to expand...
Erm i guess you could put it that way. In theory,Nothing is set in stone at all right now but im thining I'd be using the 400 block out of the blazer with a aftermarket bottem end and a vortec 350 top end which would include the vortec 350's EFI set up. :dunno:

Well im years away from racing but im thinking KOH type of stuff. IIRC W.E rock just came out with a Dirt Endurance type of series that looks awesome. Although its about 2000 miles away from me :doah:.
 
Multi Port Fuel Injection.

You don't want the Vortec EFI set up.

Martin
 
If you can find an aftermarket intake with the fuel rails and injectors you could wire the vortec harness to fire each injector and reprogram the computer for the 400 small block. Was going to do the same thing a few years ago but found a complete running big block.
 
Edelbrock MPFI is nice but pricey.

I opted for the cheaper Professional Products MFPI since I already had an Accel DFI ECU.
72012_1_.jpg

http://www.professional-products.com/EFI_2.php

The manifold with injector bungs was $180 shipped, throttle body was $350, 8 55lb injectors were $100 used, fuel rail kit was $200.
 
Shawn said:
Edelbrock MPFI is nice but pricey.

I opted for the cheaper Professional Products MFPI since I already had an Accel DFI ECU.
72012_1_.jpg

http://www.professional-products.com/EFI_2.php

The manifold with injector bungs was $180 shipped, throttle body was $350, 8 55lb injectors were $100 used, fuel rail kit was $200.
Click to expand...
What heads are you running and is that a 406 BBC or a 400SBC bored out? What kind of numbers did you get if you've dynoed it?
 
gotblazers said:
What heads are you running and is that a 406 BBC or a 400SBC bored out? What kind of numbers did you get if you've dynoed it?
Click to expand...

Bored 400 SBC. Running AFR alum. heads. Still in the building stage. Had a bad 400 block with a crack so I just ordered a Dart block to replace it. CHP magazine did the Impersonator II and made 525 lb-ft and 490 hp and this was with the older style AFR heads (flows less), smaller cam, and less compression than what I'm running along with a basic carb. Mine should make well over 500.
 
Last edited:
We were working with a TPI not a TBI. We went to a company that specializes in TPI's and bought their high dollar level V custom chip. Like I said after much back and forth and numerous attempts at a chip that would run right, we both gave up. It might have just been an isolated incident, I don't know. I will admit is is difficult to get a chip to operate perfectly when you are over a thousand miles from each other.


63chevyll said:
We had luck with a hypertech chip and 454 injectors on a tbi 400. I don't have all the details but it was a customers K5.
Click to expand...
 
As much as I like the L31 Vortec 350's, the injection on them was not a real good design. They certainly don't lend themselves well to modified engines. With the poppet design of the 'spider' style injection, and the fact that you can't change the injectors like a regular MPFI system, you are very limited on just how much HP it will support. Just to change the 'spider' to the updated version is over $400.00. You can buy a good set of regular injectors for that price.

Either way you go, setting up a fuel injection system for a performance engine, particularily a 406, isn't going to be cheap by any means. Especially if you don't have the knowledge and skills to build a system and tune it yourself. You could learn a good bit about what it takes to build and tune a EFI by reading on some of the forums that deal with EFI. In fact there is some very knowledgeable guys that hang out in the injection section here on CK5. Another forum that has a lot of info on not just EFI in general, but specifically the L31 Vortec system is here:

http://www.pacificp.com/forum/index.php

Quite honestly EFI setup and tuning can get very involved, and a little complicated to figure out on your own.

If you decide you just want more of a plug and play EFI, I would recomendeither one of the Edelbrock or Holley systems. I kind of like the Edelbrocks Pro Flo XT's.

gotblazers said:
So what aftermarket injection set up would you recommend to make this work. I've looked at a few in the past and they are always priced at what seems IMO to be outrageous.
Click to expand...
 
The GM ODB1 ECU's aren't the easiest to get right with mail order chips. Any custom engine setup should be tuned on the dyno but its hard to find shops that can tune GM ODB1 these days. I know the Sylcone/Typhoon guys are having good luck with code59 and the stock ECU. Code59 is a heavily modified sy/ty program, that adds closed loop wideband, expanded tables, water/alky injection, better fuel computations and a bunch of extra's. If you put a reluctor wheel on the crank pulley it will also DIS ignition for you.

Some stuff you'll need is here for ODB1 tuning:

http://support.moates.net/2009/05/07/gm-86-95-obd1-guide-read-me/

Luckily I found a good deal on this Accel Gen VII ECU and harness.

acceldfi.jpg

 
Ok back on topic lol.

I have a few break in questions. Ill get a good breakin oil, rev it to at least 2000 for 20 min. Only thing i was thinking is what about the whole bleeding the radiator thing? How will it cool right with all those air bubbles and such?

And I want to get my carb rebuilt (i have the kit to do it) but idk what im really doing and what if the carb needs adjustments after I turn it on? If I start it is it a "Your in for it now, no turning back" or can I shut it down and mess with stuff like if the temp spikes super high or something?? Little things like that are just kinda scaring me i guess.
 
You must log in or register to reply here.

Latest Posts

Top Bottom