Nitrous on a 93 roller block 347ci - comments

[washMO66]

I saw the other thread on this and rather than Hijack I figured I would start another thread. I have been wondering what mine would take if anyone would care to comment... I was thinking about a 100 shot..... Keep in mind this car is just a toy and not a daily driver by no means, I street it and track it and intend to run points next year at my local track and do some bracket racing. My cage is finally done now that the season has completed and my winter projects include a 3.70 to 4.11 gear swap, new fuel system and change the 40 year old wiring completely (long time coming). Car should run very low 11's NA after the gear change....

93 roller block - 347ci rotating assy fully balanced (was just freshened up, rings & bearings and everything looked to be in great shape, original build done in 03')

KB hyper domes

Forged rods / crank

475HP FWHP

10.8:1 compression

Ported / polished AFR185's

XE282HR - I spin it up to and shift around 6500RPM

I have heard a few 5L stock block bad stories and other people saying that it will hold for a season or two.

 

[mustangdave]

First, why are you spinning it to 6500? Are you sure the power is still climbing after 6,000 r.p.m.'s? I f you haven't already tried it, I would shift at 6 and see if you lower your e.t.
Nitrous, hyper pistons, and a stock block that is laready making big power like yours is pushing it, but a 100 shot should be o.k. if you back your timing off a little. A better aidea would be to invest in a timing retard that activates automatically when the nitrous kicks in, (at 3,000 r.p.m.'s or above). Are you using a carb. or e.f.i. If you using the factory e.f.i., you are already way above what the factory injectors can handle.

 

[mustangman70]

Nitrous, hyper pistons, and a stock block that is allready making big power like yours is pushing it, but a 100 shot should be o.k. if you back your timing off a little.

What he said

 

[washMO66]

First, why are you spinning it to 6500? Are you sure the power is still climbing after 6,000 r.p.m.'s? I f you haven't already tried it, I would shift at 6 and see if you lower your e.t.
Nitrous, hyper pistons, and a stock block that is laready making big power like yours is pushing it, but a 100 shot should be o.k. if you back your timing off a little. A better aidea would be to invest in a timing retard that activates automatically when the nitrous kicks in, (at 3,000 r.p.m.'s or above). Are you using a carb. or e.f.i. If you using the factory e.f.i., you are already way above what the factory injectors can handle.

See my sig, race demon 775.

The Cam is advertised to make power to 6600 which based on how well my heads flow is why I switched from an XE274HR. I have had the car on the dyno and it makes good power up to with the Vic Jr and spacer plate.

Have not had it back to the track to experiment with shift points but when I had the XE274 it ran the best ET's shifting at 6000RPM, given the CAM characteristics I would think the power has moved north a bit..

 

[iskwezm]

I wouldnt go more then 100 shot with 10.8:1. SHould get you into the 10's easy.

 

[BullittStangV8]

Girdle on the block?

 

[Sicarius428]

Stock HO blocks are pretty reliable to about 450hp. Some lucky few have been able to push theirs farther but understand its on borrowed time. Assuming that your setup is about 400hp NA, I would imagine that a 100 shot will most likely be the end of the block. Girdles dont make the block stronger. They just hold it together when it does go.
Kevin

 

[1320stang]

I'd hit it!!!

Seriously though, I'd start saving up for a new shortblock to run in '08. Aftermarket block, shoot you might even want to go to a windsor, but then you'd end up giving up your just returned Vic Jr unless you used some spacers.

 

[washMO66]

Stock HO blocks are pretty reliable to about 450hp. Some lucky few have been able to push theirs farther but understand its on borrowed time. Assuming that your setup is about 400hp NA, I would imagine that a 100 shot will most likely be the end of the block. Girdles dont make the block stronger. They just hold it together when it does go.
Kevin

You are correct, my girdle will only help me to find all the pieces quicker... I assume your talking rear wheel HP which is right at what I have on both HP and tq #'s.

An aftermarket block is in the cards for the future. This engine has been a sweetheart for a mild 347ci street strip set-up. I am just greedy and needy when it comes to ET #'s and speed. I still haven't made a pass on the current set up since we freshened it up and gave it more cam and stall (and soon gears). I just got it back from getting the cage and the cage needs painted, carpet needs replaced and of course the gear swap. I would love to get a 10.9X NA before I spray but I think in reality it is only gonna give me an 11.09 or an 11.1X. We'll see...

 

[10secgoal]

I think you would just be in the boat with the rest of us. Will it? Yes if it makes an honest 475 ( I do belive you), but plan on it checking out early. I got lucky and never split mine. But Ill be testing the stock crank here pretty quickly.