Update on my 383 TBI

[91Chevy]

Were you ever able to get it on a dyno and see how much it put down? The reason I ask is because I'm actually looking at getting the same 383 for my 91 and wanted to see how much power you wee able to get out of it with your setup.

[UATahoe]

Actually, I should be getting it on a dyno at the end of the month. I am thinking about moving away from the tbi computer to a mega squirt system so I can really dial in the tuning and get away from the tbi chip. Still keeping the throttle body but changing out the electronics. I will post back up when I get it going.

[chris989]

Originally Posted by UATahoe

Just a quick update. Have about 500 miles on the drivetrain now. Truck is running awesome. After a few iterations of tuning with Brian, really have things dialed in now it seems. Looks like i am getting about 15-16 mpg city driving which i was very happy with. Plus, there was a lot of idle time and heavy throttle in there running data. Also a lot of driving to get the TV cable setup correctly. All in all, the new power is crazy compared to the old V8. Truck is night and day different now. Glad to report 0 leaks as well. LOL.

UAtahoe,

how is the truck? I am beginning my build now and would like to know the final cam/head details and are you happy with the final Bin from Brian.

[UATahoe]

Well, things have shifted directions dramatically. I have been trying to run down electrical issues for quite a while. I had an ls1 sitting around that was supposed to be used for a 67 camaro restomod. Well, that project fell by the wayside and I have decided to out the ls1 in the truck. Pulled the 383 last weekend actually. Lol.

Brian was good to work with but I was never able to get it dialed exactly right. The Dino showed it was running pretty lean at wot. The normal driving seemed to be ok though.

[chris989]

Do you know the cam specs? stock vortec head?
Do you have a guess as to what caused the lean issue?

[UATahoe]

Stock vortec heads which were a mistake. Caused a lot of drivetrain issues. Wish I would have went with different heads. The cam was very mild. I will have to look for the specs. Not really sure what the lean issue was honestly. The tune just wasn't well dialed in.

[68c10owner]

Originally Posted by UATahoe

Stock vortec heads which were a mistake. Caused a lot of drivetrain issues. Wish I would have went with different heads. The cam was very mild. I will have to look for the specs. Not really sure what the lean issue was honestly. The tune just wasn't well dialed in.

How did the vortec heads cause drivetrain issues?

[UATahoe]

Sorry, should read valvetrain issues. Autocorrect got me. The guy I got the engine from didn't cut the guides down properly to run the vortec heads with the cam he installed. Ended up beating the hell out of the valve seals. Had to replace 2 seals before the heads came off and went back to the machine shop. If you run a stock cam or very very mild cam you should be fine. I just wish I would have gone with different heads that had more potential. And ultimately, it really falls back to the engine builder and I will avoid the one who built my 383 forever. Just didn't do a good job.

[slotard]

Looking forward to the LS swap. What tranny? Megasquirt or tuned stock ecu?

[UATahoe]

Going with the 4l60e and I am keeping the stock ecu. Harness should be arriving this week from having it converted to a standalone harness. Looking forward to the reliability once I get it up and running.

[slotard]

This is an actual LS1 out of a transmarobird or Gto rather than a truck engine?

And yeah, there's something to be said for a setup that just works.

[UATahoe]

Yep. This is a motor out of an 02 SS camaro. I guess most use the truck motors because they are cheaper? This one definitely won't drive like a pickup. Lol. Hopefully that won't be a problem. I am thinking the different powerband will be fine.

[jokerz71]

Originally Posted by UATahoe

Sorry, should read valvetrain issues. Autocorrect got me. The guy I got the engine from didn't cut the guides down properly to run the vortec heads with the cam he installed. Ended up beating the hell out of the valve seals. Had to replace 2 seals before the heads came off and went back to the machine shop. If you run a stock cam or very very mild cam you should be fine. I just wish I would have gone with different heads that had more potential. And ultimately, it really falls back to the engine builder and I will avoid the one who built my 383 forever. Just didn't do a good job.

Any cam with .450 up lift, the seal to retainer clearance has to be measured & if not adequate, provide more clearance by machining, or, spring retainer upgrade.As for potential, the Vortecs will support alot more HP than the tbi computer can be tuned for.Portwise, they can be a lil small for a 383, but, with a proper spec'd cam & setup,450 HP is obtainable.
If you were running lean at WOT, you were likely short on fuel supply.

[UATahoe]

True. Had plenty of fuel, the tune was just off. Went from too rich all the way to too lean. All the while working through the heads issues. You are right though. My problem was just a poor engine builder from the get go.

[jokerz71]

Originally Posted by UATahoe

True. Had plenty of fuel, the tune was just off. Went from too rich all the way to too lean. All the while working through the heads issues. You are right though. My problem was just a poor engine builder from the get go.

If the Bryan you were speaking of is Bryan Harris of TBI Chips, we've not had luck with him on mail order chips.Been thru several chips with little success.To his defense tho, doing a mail order chip without live data can be hard to nail down.
I'm guessing he also had you using his 18# spring.Haven't any luck with those either.IMO, that is no more than a rip off.The fuel psi has to be adjustable. At 18 psi, or, higher, you need a vacum referenced regulator.
I guess since you're going LS, this is all moot anyway.

[UATahoe]

It's good discussion though! And yes that is who I used went through a out 8 chips. It is hard but it grew old. And yes, I started with his spring but it just didn't work. So I switched to a fully adjustable regulator. After that, I got the fuel dialed in but started battling the actual motor problems. Got tired of it and said screw it. lol. Hence the ls project.

Brian is a good guy, but it wasn't a very good experience for me. A lot of good talk but none of it really came to fruition. I learned my lesson with the mail order thing. Not a fan. Would rather put the control in the hands of my local tuner. He will be tuning my ls.