454 TBI Build

[Sla90lx]

Hey guys, been a while since I've posted. I know I'm prolly gonna get flamed on this one but I've built a 454 for my sons 95 ECSB OBS. I've got pretty much everything done except for paint and transmission. I will prolly have a lot of questions as I try to fire this thing up and especially when I go to dial it in.
Here are some specs:
Standard bore 94 genV block
Flat top stock pistons
100cc 96 vortec heads, steel roller rockers and springs for cam
9-1 compression
Lunati 60203 cam, maybe a touch to much
.542 in .554 ex. Dur 227 233 @ .050"
Holley tbi, MSD dist, dynomax shorty headers

Thinking between 400 to 450 HP
Question for now is which fuel pump? I was thinking of going with 96 up vortec truck pump after talking with the manufacturer (airtek). Next concern is the break in. Should I just throw a Holley I've got on it for that or can I start off with a base tune close enough to not blow this thing in the first twenty minutes of it life?
Thanks for reading this and I look forward to your responses.
Chris.

[EagleMark]

Get roller rockers while you replace that cam with something smaller.... :innocent2:

[Fast355]

Get roller rockers while you replace that cam with something smaller.... :innocent2:

That much cam in a 454 is like have a 215-220* in a 350. The cubes swallow the cam pretty well and the big block will have more vacuum than a small block with the same cam specs.

[Sla90lx]

Yea, I know in the big block world that cam is very mild. Shortly after I built the motor I found someone who had built an almost identical set up and compaired that cam with the 60202. It had more torque but the same hp with those heads the limiting factor.

[Nasty-Z]

Have you done any work to the heads ? You will need to address guide height as well as a good spring package with rotator eliminator with those heads . They cannot be left stock with almost any aftermarket cam .

I have built quite a few 454 combos with the Vortec heads as well as a few 496's , excellent performer for the $$ spent , the heads will support more than most think .

I would loose the Holley TBI and find a good 454 Unit . Oh , and the Vortec F/P or a TPI pump will be fine.

TOM

[Sla90lx]

Tom, thanks. The heads are ready to go. I have the throttle body off of the ,sorry, 92 not 94 454. Picked up the holley real cheap and saw that the bores were larger than the gm. So stock would do better huh?

Chris.

[Nasty-Z]

Both the Holley and a BBC TBI unit share the same bore size @ 2" .

The factory unit is better by far .

TOM

[Sla90lx]

Okay. Did a search on comparisons with no luck. I'm sorry, I just like to know why something is different or better. It's been a few months now but I remember measuring both and seeing a touch difference in size, and I know holley claims it to be 670 cfm. Not saying I don't believe you just maybe myself.

[Nasty-Z]

The Holley 502-6 (or 502-9) TBI unit has 61 +/- PPH injectors and the regulator is good for around 20 psi +/- IIRC , with the regulator turned all the way up the Holley injectors will flow right around the 80#/hr the 454 OE injectors do @ 13 psi . There is a lot more room to grow with the OE unit. The Holley unit was never designed to replace a OE 454 TBI , it was sold for SBC engines as an upgrade over the OE SBC unit.

Holley used to offer an 85 pph injector but the replacement TBI unit that used these injectors was not a direct bolt on like the 502-6 (502-9) or the OE unit .

The MAP port that Holley wants you to use is at the rear of the unit , it intersects the IAC passage , if you are dead set on using the Holley unit , run the MAP sensor directly to manifold vaccum and not this port for the most accurate reading , this little detail has snagged more than one tuner.....

Stock 454 TBI uses a 2" bore , same as the Holleys , the only way you measured a difference in bore diameter is if you really don't have an OE 454 TBI and you have a small block version , the bore on those is 1-11/16" .

FWIW, the OE 454 TBI can be bored and sleeved to 2.244" max , whereas the Holley can not .

Be sure of which OE 454 TBI unit you have , 94-95 are different than the early units and run a smaller injector at a higher pressure (46pph @ 28-32psi) . The early units are 80 PPH @ 13 psi .

What intake are you planning to run with the Vortec heads ? Have you addressed the port mis match ?

TOM

[Sla90lx]

Thanks for the info. The only thing I'm dead set on, is getting this combination of parts right. If there's something that I can change now and avoid headache latter I'm all for it. I just measured both TBs again, stock 2.000 holley 2.025. I'm not trying to split hairs, just telling ya what I have. I see the map port and agree that's poor placement. I have started an album of this build I'll put a few pics of the TB and injector in there. I'm using the edelbrock rpm and did not see any port or alignment issues. I hope there's not something I've overlooked with that. Oh and it was a 92 which doesn't matter cause someone robbed the injectors before I got back to pull the engine.
Chris.

[Sla90lx]

Okay, time to move this one back to the front burner. I have run across an accel dfi setup and wanted to know if you thought this was better than tbi or overkill for my mild combination. I don't think I wouldn't use the gen 6 controls but rather a gm computer if doable. If I go tbi the gm tb needs injectors. The holley looks like a better unit and I like the pressure reg on it. If I can get the 85 pph injectors and run map to intake, are there any other problems with this tb? I know I'm overanalyzing this, I just want it right. If y'all tell me gm tb then that's the way I'll go.

Thanks, Chris.

[buddrow]

I would stick with the Gm ecm/pcm. You will find more information and assistance(especially here) dealing with GM ecm/pcm than the aftermarket stuff. They are quite flexible to a point and your mild build is perfectly suited for it. Anywho, go factory and you will be happy. It's relatively inexpensive to buy tuning equipment for OBD1 stuff. Just my 2 cents worth. :)

Buddrow

[kevinvinv]

I am just finishing a Gen V 454 with stock TB and peanut port heads. Someone asked earlier if you had addressed the port issues with sticking your Vortec heads on the Gen V block? I hope you didn't overlook this little tidbit :)

I am no expert but I certainly would go with the stock TB as well. Undoubtedly there will be problems and the less "Frankenstein" you have the better :)

I am curious if you used roller rockers- did you use tall valve covers? If so- did you get the EGR valve to fit or bypass it?

I made my first "adjustment" to my bin just the other day and it actually did something... so I guess I am "going in" .... :)

BTW- you have a 4L80 trans right?

[Sla90lx]

Still don't know about the port issue. I'm using a performer rpm manifold and everything looked like it lined up proper. Yes, full rollers, tall valve covers. No egr. Was your "adjustment" positive? It's rewarding when you start going in and getting the results your looking for huh? Prolly gonna build a 4l60 to handle the torque.

Chris.

[kevinvinv]

Sounds good. I am no expert but when I started bulding my Gen V I was initially very interested in the Vortec gen 6 heads. I steered clear of them in the end b/c of the coolant passage issue (I think) and also the difficulty getting a TBI manifold to bolt up to them... now it sounds like everything isn't as bad as I thought... so you might have a good combination there.

Maybe you are also on top of this but to run the 454 with the 4L60E you'll have to do some special chip work to merge the 454 engine code in with the 4L60E trans code... or is your 4L60 not computer controlled? I got my 4L60E from Finish Line Transmissions and it is supposed to be strong... I guess we'll see about that!!

I think my "adjustment" was positive ... getting rid of some knock... but I seem to be having some TCC clutch engagement issues that I am pretty worried about right now... not sure when they showed up... but that is next on the list I guess!!