If I put a stroker kit in my 454 will it run without a tune?

[techweenie]

I'm getting started on rebuilding my 454 Vortec and really want to put a stroker kit in it. Do any of you know if it will start and run without a computer tune? I'm also putting a comp cams complete valvetrain kit in it which is compatible with the computer.

 

[techweenie]

Reviving this question because I'm getting closer to rebuilding the engine. I have almost everything needed except the bottom end. I've asked a few manufacturers and no one seems to know.

 

[Chewy1576]

Speaking from experience with my SB 383, it ran with the stock 350 chip, but not very well. It took tuning to make it run smoothly and get all of the power out of it.

 

[Supercharged111]

It's anyone's guess. If it does run, it's going to run like . Why do you want to run it without a tune? Even a stock engine wakes up tremendously from a tune. You're willing to spend money on a stroker but not a tune?

 

[techweenie]

The intention is not to drive it without a tune, I merely need to know if it will start and stay running well enough to know it works. If I can drive it to a tuner then all the merrier. I could go straight to a 411 pcm and coil near plug, but that seems like too many changes at once to be able to troubleshoot any issues. I'm aiming for incremental upgrades and will tune along the way.

 

[Supercharged111]

How big of a cam? One way to cheat a little is to either bump fuel pressure or buy larger injectors. This makes the tune a little less wrong and better chances of it running good enough to move under its own power, but that cam could really screw you if you got something halfway decent.

 

[Chewy1576]

It will most likely be lean to start so the PCM will add fuel to try to compensate, but it will only allow so much. Bumping fuel pressure or bigger injectors like Supercharged111 suggested could help.


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[techweenie]

Thanks for the help guys. The cam is the only one available from Comp Cams for the computer controlled fuel injected 454. I can pull up specs if you really want to see. Shouldn't be too aggressive. I bought all new bosch fuel injectors from ebay quite a while ago, so it'll suck if I have to buy new ones all over again. But if that's what it takes then so be it.

 

[Supercharged111]

You'll be dollars ahead then to pay for a tune instead assuming the injectors have the headroom.

 

[Tech]

It will likely run, It's just that the base calculation that everything is based off of is now incorrect. It's expecting 454cu" of air per cycle and it is actually pulling 500cu". 10% is not a huge change.
A windage tray and roller rockers could improve your efficiency enough to put you back in tune.
Different cam, injectors and stroked..., I would put a tune fairly high on the list.