My 383 TBI project

[Doober]

Here's the thread for the 383 I plan on building for the truck... hopefully I don't forget to update it

Plans (for now at least) are to use the TBI heads already on it, run a 454 TBI unit, and most likely the GM roller hot cam (218/228 @ .050", .492"/.492" lift).

Where I am so far...

 

[Doober]

Re: My 383 TBI project (TB383I)

Took most of the rest of the engine apart a couple hours ago... 4 of the pistons (accidentally) popped out of the bores before I even ran the ridge reamer... so there must not be too much wear 8)

 

[malibuSSwagon]

Re: My 383 TBI project (TB383I)

Ditch those crap TBI heads and get some Vortecs. You can just use a vortec 4bbl intake with a $20 4bbl to TBI adapter, that way you dont need the $350 Vortec TBI intake

 

[Doober]

Re: My 383 TBI project (TB383I)

I already have a GM TBI to spreadbore adapter. I'm using the TBI heads because Vortecs are likely not in the budget this time around.

 

[malibuSSwagon]

Re: My 383 TBI project (TB383I)

I already have a GM TBI to spreadbore adapter. I'm using the TBI heads because Vortecs are likely not in the budget this time around.

bummer, well The heads are just good for low end torque, but i'm sure that is what youre looking for.

 

[Doober]

Re: My 383 TBI project (TB383I)

Yes, I am familiar with the heads. Believe it or not some cleanup/porting will help.
http://www.thirdgen.org/techboard/tbi/2 ... 193-s.html

Lift  Intake Exhaust
.100  72.4   60.5
.200  133.4  124.2
.300  180.6  171.5
.400  209.3  196.3
.450  217.4  203.7
.500  224.3  215.6

Testing of Vortecs for comparison (first flow test in the article):
http://www.chevyhiperformance.com/techa ... index.html

Lift	 Intake  Exhaust
.100 	66	   57
.200	 129	  101
.300	 186	  136
.400	 219	  149
.450	 225	  150
.500	 216	  155

So given some love, I think I'll be ok.

 

[Doober]

Re: My 383 TBI project (TB383I)

Took one of the heads apart last night, gonna try to do some cleaning on the ports, maybe the chambers too.

 

[Doober]

Re: My 383 TBI project (TB383I)

Started cleaning/shaping the ports today, I'm trying to take as little material out as possible, just trying to smooth out the ridge right at the port for the most part. Still undecided if I'm going to just smooth the ramp or change its shape as well. I was a little concerned if a $43 Dremel would be up to the task, but it seems to be handling it well 8) I just need some safety glasses & will probably need quite a few more grinding stones.

 

[olds307 and 403]

Re: My 383 TBI project (TB383I)

I too am doing upgrades to my TBI Olds 350 truck. I already did the salad bowl under the air cleaner mod, poor man's power charger . I will be grinding the stock TBI for more flow, adding the injector spacer and rebuilding it. I also have a factory A4 aluminum intake coming, looking for maximum low end torque with tire spinning full throttle blasts. The Olds 350 is great for torque, even with the small port SP2P intake, just limits full throttle too much. The Factory 454 adapter works great on a 4bbl intake. I just got a valve spring compressor, tons of valve seals lying around. Puffs blue on start up, you would almost think the sbc was still in there .

 

[Doober]

Re: My 383 TBI project (TB383I)

More grinding...