Carb to TBI

[Irishman999]

Tossing around the idea of going TBI in my 85, I already have my mind set on building a TBI engine. Going to go check this out this weekend:

http://tucson.craigslist.org/pts/3091203540.html

Plans for my engine build include a full scat rotating assembly, roller valve train and a mild cam for low end torque. I will hopefully be rebuilding the stock heads that are on it.

My question is: How much work work would be involved if I decided to go TBI in place of a carb? Is there a simple stand alone system I can just bolt on and go without changing out the factory wiring harness and a bunch of other nonsense?

So far I have found this-
http://howellefi.com/tbi-kit-universal-v-8.html

 

[Guardian]

I don't know what your budget looks like, but there are several stand alone systems out there. The FAST system or the MSD system do not require programming because they are adaptive.

http://www.summitracing.com/parts/MSD-2900/

http://www.summitracing.com/parts/FST-30227-KIT/

It's just a thought.

 

[Irishman999]

Those are some good links, I plan to spend some money on this build but 2k is about twice what I thought this would cost! Those dont have EGR, I forgot to mention I want to run all emissions stuff.

I recall my uncle having a truck about 6 years ago that my cousin converted to TBI. I think he said they got the throttle body and the intake from the junk yard and had some kind of kit that they plugged in without having to change wiring harnesses.

 

[Guardian]

Those kits will use the carb intake so if it would use the existing EGR.

The system you listed will work good for mild upgrades. The issue with the TBI unit is it is very sensitive to changes to internals on the engine. Since the TBI injectors are above the blades it reacts much like a carb and the program will be the limiting factor.

 

[Jims86]

Plug and play.
I can walk you throught the whole swap on the phone.
I usually separate the Chassis harness, and all of my conversions are stand alone.
that Howell harness would be perfect, and even easier, because everything is labeled.
You will need a Vehicle speed sensor, if you already dont have one behind the dash. they make inline sensors if you dont.
Tell them you need an exact 87 truck harness, with the TBI distributor, knock module and sensor, egr solenoid, and speed sensor. That one pictured is just bare bones.

That TBI engine would be good, But let me warn you, those heads are no good for high performance, but are very good low end, MPG heads.
If that engine is out of a GMT 400, those Exhaust manifolds will not fit between you rails, bit your current ones will bolt up with no problem, as the heads have 7 bolt locations for the exhaust manifolds. The heads do wake up a little , with exhaust porting
For a roller cam, look at GM performance P/n 14097395, its the roller cam from the HT383e, it works well with TBI.
You can use your existing hard lines for fuel, but use the EFI stuff for the soft line connections.

If you had all the parts laid out in the garage, and knowing your mechanic skills, you ca complete the swap in a little less than a weekend, that is, if the engine rebuild and install were done already.

I will say, That $3000 FAST setup was real nice when it finally tuned itself to the 396 Chevelle I installed it in last year....the owner has gone through 5 sets of rear tires so far.

 

[usar17]

For the price of most of these kits you could also go with the Edelbrock E-Street EFI Plug and Play self tuning system.

http://www.edelbrock.com/automotive_new/mc/efi/estreet_intro.shtml

http://performanceparts.com/part/Edelbrock/3600

 

[Irishman999]

Plug and play.
I can walk you throught the whole swap on the phone.
I usually separate the Chassis harness, and all of my conversions are stand alone.
that Howell harness would be perfect, and even easier, because everything is labeled.
You will need a Vehicle speed sensor, if you already dont have one behind the dash. they make inline sensors if you dont.
Tell them you need an exact 87 truck harness, with the TBI distributor, knock module and sensor, egr solenoid, and speed sensor. That one pictured is just bare bones.

That TBI engine would be good, But let me warn you, those heads are no good for high performance, but are very good low end, MPG heads.
If that engine is out of a GMT 400, those Exhaust manifolds will not fit between you rails, bit your current ones will bolt up with no problem, as the heads have 7 bolt locations for the exhaust manifolds. The heads do wake up a little , with exhaust porting
For a roller cam, look at GM performance P/n 14097395, its the roller cam from the HT383e, it works well with TBI.
You can use your existing hard lines for fuel, but use the EFI stuff for the soft line connections.

If you had all the parts laid out in the garage, and knowing your mechanic skills, you ca complete the swap in a little less than a weekend, that is, if the engine rebuild and install were done already.

I will say, That $3000 FAST setup was real nice when it finally tuned itself to the 396 Chevelle I installed it in last year....the owner has gone through 5 sets of rear tires so far.

Thanks Jim! I read about these heads in my book, I guess I could port them a little but I am not that concerned. I am shooting for a solid 350 HP and good torque, a nice surprising amount of power is all I need for the 85.

I might still go this route, if I do decide to, you will be the first person I contact.

For the price of most of these kits you could also go with the Edelbrock E-Street EFI Plug and Play self tuning system.

http://www.edelbrock.com/automotive_new/mc/efi/estreet_intro.shtml

http://performanceparts.com/part/Edelbrock/3600

Thats a good link, that unit looks promising. My big question about it is my vacuum line mess I want back on my engine. I was planning on hooking up the little thermal vacuum tree's and getting the emissions controls working again, if I go with this unit I wonder if it would eliminate the need for all that stuff?

I do really like the fact that I can put my factory air cleaner lid on!

 

[usar17]

All i can make out from the pics are the main port vacuum. Might be worth emailing Edelbrock. I've been tossing around this purchase myself now for sometime

 

[Jims86]

If you go with Factory TBI, which is the only EFI emissions capable system,you will only have:
1 vac line for the map sensor
1 vac line for EGR
1pcv line to manifold vac on T body
and 1 breather line
If you need it in AZ, 1 vacuum line to the Charcoal cannister
That E-street system only has PCV provision, and using the thermal ported switches with that system, may cause a problem, because it wont expect to see egr...not that it would know what it was, but anything that The Computer is not commanding, wont get a very welcome reception.
Even the old Computer q-jets had a computer commanded egr.
I have heard of over 350 hp with TBI heads, just communicating with the guy that did it is almost impossible. He is known as Fast305 on FSC, and he has done some out of this world stuff....like adding Mass Airflow system to TBI.
You can also goof with some Camaro TPI heads from an L98 if you can find them...they flow a little better since they dont have the swirl ramp in the intake.
Dont get stuck on HP though, Focus on Tq....TBI heads with TPI induction got me 403 FtLbs TQ, but the hp was only 230. 16 to 20 mpg was not uncommon. 23 mpg has been achieved with TBI in trucks like yours.

 

[Irishman999]

If you go with Factory TBI, which is the only EFI emissions capable system,you will only have:
1 vac line for the map sensor
1 vac line for EGR
1pcv line to manifold vac on T body
and 1 breather line
If you need it in AZ, 1 vacuum line to the Charcoal cannister
That E-street system only has PCV provision, and using the thermal ported switches with that system, may cause a problem, because it wont expect to see egr...not that it would know what it was, but anything that The Computer is not commanding, wont get a very welcome reception.
Even the old Computer q-jets had a computer commanded egr.
I have heard of over 350 hp with TBI heads, just communicating with the guy that did it is almost impossible. He is known as Fast305 on FSC, and he has done some out of this world stuff....like adding Mass Airflow system to TBI.
You can also goof with some Camaro TPI heads from an L98 if you can find them...they flow a little better since they dont have the swirl ramp in the intake.
Dont get stuck on HP though, Focus on Tq....TBI heads with TPI induction got me 403 FtLbs TQ, but the hp was only 230. 16 to 20 mpg was not uncommon. 23 mpg has been achieved with TBI in trucks like yours.

I was thinking exactly what you just explained. I dont have to pass smog in the county but I still want my truck to be set up with all the emissions back in place, I am burned out on the whole cleaned up look and everyone having the same cheap chrome valve covers, chrome edelbrock air cleaner and everything spray painted chevy orange, okay rant over.

I am kinda tossing around the idea of just going back with a quadrajet, Jim, how do you think a Qjet will do on a TBI motor with TBI heads? I am thinking of just getting the Edelbrock spreadbore performer and running a reman unit.

 

[usar17]

now ur into my build lol

I just got a '87 350 TBI from a k20. I'm dropping an edelbrock 3706 performer intake on it with a rebuilt qjet M4MED on it. My other thread ppl said the TBI heads with a qjet work great. I may add a cam down the road then.

 

[Jims86]

I was thinking exactly what you just explained. I dont have to pass smog in the county but I still want my truck to be set up with all the emissions back in place, I am burned out on the whole cleaned up look and everyone having the same cheap chrome valve covers, chrome edelbrock air cleaner and everything spray painted chevy orange, okay rant over.

I am kinda tossing around the idea of just going back with a quadrajet, Jim, how do you think a Qjet will do on a TBI motor with TBI heads? I am thinking of just getting the Edelbrock spreadbore performer and running a reman unit.

YES!!!
Q-jet and TBI Heads work very well together.
Edelbrock 3706 is what the doctor orders!
Then you can go ahead and use your ported vacuum switches for egr. If you still havebyour old vacuum diagram, that would help.
Carburetor also opens up more camshaft options...like maybe the regular HT383cam.
Also, if you get that manifold, make sure you get the EGR spacer, so you dont end upnwith any clearance issues.
Definately port the exhaust side of the TBI heads, just open them up a lttle to maybe match the gaskets.

 

[Guardian]

Always gasket match the exhaust, it is worth the time and effort on any sbc.

 

[MrMarty51]

l good articles about doing the conversions in here.
http://www.diyautotune.com/tech_articles/tech_articles.htm
I purchased one of their Megasquirt controllers,it comes in a kit and You solder in all of the components onto the board.
I do`nt have anything,yet,to attach the fuel/spark controller to but it will happen,I think when I instill a 3.8 turboed Buick into one of My MG B roadsters.

 

[usar17]

*Bringing this back alive

My 85 K10 has been dead in the drive way since november now. Rings are....gone probably lol and i don't have a garage or anywhere indoors to work on her.

My original plan was to pull a 350 out of a 1987 C20. Claimed to have been rebuilt with under 10k miles on it. Swap the intake for a an edelbrock 3706 and keep my qjet and vac lines. Easy, $150-$200 for intake, no electronics still.

Further thought of reliability and MPGs has made me think of keeping the engine as is, TBI.

Question:
Besides the actual engine swap, what else would need done?

Sensors? ECM? All new Wiring Harness (I already assume this)? Dash Cluster?

Worth it or not? I'm trying to keep this low budget.