Hot Rod Forum banner
1 - 12 of 12 Posts

·
Registered
Joined
·
42 Posts
Discussion Starter · #1 ·
I'm thinking about rebuilding my 1993 454 BBC. It only has 288K miles on it so I might be a little premature. I'd like some recommendations from this forum on rebuild kits, please. I would also like to get a few more horses out of it. Originally it's only 230 hp. Does have TBI. Ideas?
 

·
Registered
Joined
·
127 Posts
Yes you would get rid of the computer, go to a regular HEI distributor and carbuerater and intake manifold of your choice. Would also have to use a fuel pressure regulator to control lower psi for carb. Im sure there are many conversion posts on here you just have to search them.

Sent from my SM-G965U using Tapatalk
 

·
Registered
Joined
·
15,301 Posts
It is complex to get more power with the TBI, it doesn’t take much of a cam change before you’re face with a reprogramming the chip situation.

A 454 if an automatic will have the electronic computer controlled 4L80E transmission so you can’t lose the computer entirely.

If the above is the case, then yes you can convert to a carb that mounts a throttle position sensor, this will be an extra cost add on, Holleys are probably the easiest in this regard. A standard HEI distributor is used with the tach signal going to the computer. This will give the computer enough info to allow pretty normal gear selection to where you shouldn’t notice the changes.

The fuel system with the in tank pump can be used with a bypassing regulator to get the 12-15 psi TBI pressure down to a carb friendly 4 to 6 psi. You’ll want a gauge. With the computer receiving a tach and oil pressure signal as it now does with the TBI no rewiring is required, not that you can’t if you want to.

If this has a manual gear box then all you need is to fiddle the fuel pump wiring so it no longer needs the computer.

Bogie
 

·
Registered
Joined
·
42 Posts
Discussion Starter · #7 ·
As always, thanks to both of you. My interest got piqued with an offer for a rebuilt 454 with cam, HEI, new carb, and intake for about $2800. But now the guy wants $3700. So, my thoughts went to me doing the rebuild. The info you gave me is a lot of help however, I still need info on a rebuild kit. There's plenty available but I don't want to make the mistake of buying inferior product. FYI it is the auto 4L80E trans. With all of that in mind, could I get away with just doing the top end? It would simplify the work but I was told, and most likely convinced, that just doing the top could result in problems sooner or later with the bottom end. It doesn't burn oil as yet and runs ok but I do want more horsies
 

·
Registered
Joined
·
185 Posts
As always, thanks to both of you. My interest got piqued with an offer for a rebuilt 454 with cam, HEI, new carb, and intake for about $2800. But now the guy wants $3700. So, my thoughts went to me doing the rebuild. The info you gave me is a lot of help however, I still need info on a rebuild kit. There's plenty available but I don't want to make the mistake of buying inferior product. FYI it is the auto 4L80E trans. With all of that in mind, could I get away with just doing the top end? It would simplify the work but I was told, and most likely convinced, that just doing the top could result in problems sooner or later with the bottom end. It doesn't burn oil as yet and runs ok but I do want more horsies
It has 288 thousand miles on it, Only doing the top end will cause the worn rings to show just how worn they are ,once the valves are 100% .
You did not state what your plans for the truck are, If to use it like it has been for the last 288k miles. rebuild it back to o.e.m. spec and keep the tbi.
Part of the reason it went 288k was the tbi. It controls fuel when engine is cold much better than a carb on choke does. and why cold start cyl wall fuel washing didn't force a rebuild a lot sooner.
You didn't state what your plans for the truck is, as far as usage , If you are retiring it to more fun than work, have at it.
If you are going to still work it. keep the tbi. and do a stock rebuild. and I would venture to say it is time for new injectors in the tbi unit.
The 454 you have has heads designed for torque production, not hp. torque moves you, hp sells vehicles.
Trucks need torque from just off idle to shift point. peak hp is meaningless other than it sells vehicles.
You can gain power with a little head clean up at the bowl area, and good valve job.
Remember it has 288k miles on it. 50hp has left the building since new. The full engine rebuild and clean up of the peanut port heads will get you more hp than the o.e.m. rated it at. headers will get you another 20 or so. without the need of pulling the tbi system or killing the torque production and long fat torque curve the stock 454 had/has.
 

·
Registered
Joined
·
4,426 Posts
Your TBI can handle more HP, not another 200, but it is more than capable of flowing enough air to get into 350-375hp range. But as Bogie mentioned, the stock ECM becomes the road block. And also as mentioned, you need the stock ECM to run the transmission. The easy solution is to run a piggybacked ECU. There are several that can do it, but I'm most familiar with Megasquirt. An MS2 with a relay board can be installed to do exactly as I've described - it's pretty easy and can be completed for less than $600. This will alow full control of the fuel, spark and idle control.

Regarding you 288K mile motor - it needs some TLC as far as I'm concerned - it's served someone well, time for a valve job, re-ring - basically a freshening.
 

·
Registered
Joined
·
185 Posts
As for a review of a rebuild "kit"
That is tricky, other than brand. Clevite bearings iirc owned now by Mahle (maker of pistons and such)
Felpro gaskets, with an upgrade to the one piece oil pan gasket and rubber valvecover gaskets.

But, a few things.
Do you know the whole history of the truck, I ask because at 288k miles the engine might have been rebuilt and you not know it. This is important.
You need to know if you need 30 over /40 over/ 60 over pistons.
10 under /20/30 etc maim and rod bearings.
If you know the history of the truck, and know the engine has never been opened up, you "could" guess and order 30 over pistons. and 10 /10 bearings. IF IT WAS ME.
I would wait till you have the engine apart and a machine shop has looked at the bores and told you that 30 over.
Then has looked over and mic'd the crank to tell you what sized main and rod bearings you will need after clean up .
If you are not having the block decked, remember many rebuilder pistons can be shorter from rod pin bore to piston top, They are cast this way because of deck milling. If you use shorter pistons and the block deck is not milled you will lose some compression, just something to be aware of. At 288k miles on it, I'll venture to say the machine shop will advise on the block deck getting a hair cut (milled).
If you are planning on bolting the engine back together, wait till the machine shop has measured the engine.
If they are bolting it back together and handing you a complete engine long block. Let them get the parts, but explain you like the oil pan gasket to be the one piece type and rubber valve cover gaskets, now a days they most likely already use them, as your 454 has a 1 piece rear main seal. (1991 up)
Your '93 454 if the block the truck was born with is a flat tappet cam engine. Keep that in mind. (roller cams/lifters started in 1996)
It might be money well spent to have the machine shop bolt the engine together and then have them break in the cam at the shop, if you have never done it before.
Having a cam lobe go flat at first start up will mean redoing everything again. paying to rebuild it twice is no fun.
TL: DR till you know what you need, you can't pick a rebuild kit.
 

·
Registered
Joined
·
42 Posts
Discussion Starter · #11 ·
Thanks to all of you. All great advice. I originally bought the truck to haul my travel trailer (28' toy hauler at 6000lbs) but after driving the truck it's proven to be a little too tired. Kind of like my old bones. Therefore, I started to think about the rebuild. With that thought process I started to think about a short term replacement for running around while I did the rebuild. In the scope of things I've come to realize I can buy a newer toy hauler truck for less than turning the '93 into another project. It's got a full sized tool box bed so at this point it's most likely going to get turned into a yard dog. My current look for its replacement is a 2007 GMC with 6.6 Duramax and Allison transmission for under $20K. A little high on the miles but the diesel should hold out more than the 454. Again, thanks for the comments. As always, they are very useful.
 

·
Registered
Joined
·
185 Posts
Thanks to all of you. All great advice. I originally bought the truck to haul my travel trailer (28' toy hauler at 6000lbs) but after driving the truck it's proven to be a little too tired. Kind of like my old bones. Therefore, I started to think about the rebuild. With that thought process I started to think about a short term replacement for running around while I did the rebuild. In the scope of things I've come to realize I can buy a newer toy hauler truck for less than turning the '93 into another project. It's got a full sized tool box bed so at this point it's most likely going to get turned into a yard dog. My current look for its replacement is a 2007 GMC with 6.6 Duramax and Allison transmission for under $20K. A little high on the miles but the diesel should hold out more than the 454. Again, thanks for the comments. As always, they are very useful.
Good luck, Just tossing it out there. You could get a rebuilt to factory spec replacement 454 long block, and just stuff that in it. And send your back as the core, or park it under a bench.
Just an other option that will be cheaper than replacing the truck, or making a project out of it.
P.M. and upkeep on an oil burner with miles isn't cheap, keep that in mind.
 
1 - 12 of 12 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top