Okay, i did the search route and I still have a few unanswered questions.
I fully intend to spray big on my new motor, which I intended to be a 427(4.125s x 4.060 bore), for nostalgia reasons.
Now after reading some of the stories and remembering the reason I went with an iron block(reliability and strength), I think I'm going to go smaller, like a 421 or 409.
Is there anybody spraying a progressive shot bigger than 250 right now, like 300-400?
Can this block handle that kind of hit if it is brought in on a delay?
Do I need to re-sleeve on any of these combos, 421,409,427?
Can I stay with a hydraulic big-lift cam if I plan on spraying this big.
Watching ARE's car has inspired me, probably others too.
The last question, can someone explain an offset grind on the crank?
Sorry, this is the last question, would their be a significant benefit in using the C5R heads in this application(heavy N2O) over a good P&P set of stage III LS6 heads?
Thanks for any insight.

<small>[ December 01, 2002, 04:50 PM: Message edited by: SSValet ]</small>

 

If you're going to run juice, the heads don't matter much. Some good ported LS1 heads would be fine!

 

On the LQ4 ironblock the 409, 421 and 427 can all be acheived without resleeving the block. However, most expert tuners and others will agree that if your going to spay big N20 like you plan, then you should stick with the 409 or 421 tops. The 427, like the LQ4 MTI is currently building me is a 4.060 overbore and that is the max you want to bore the block on a naturally aspirated application. This 4.060 bore would be pushing it for big N20 and your better off stocking with a 4.030 overbore for N20 which will yield you approx 409 cubes with a 4.00 crank and a 420.9 cubes with a 4.125 crank. With a 4.125 crank and an overbore of 4.035 you would get 422 cubes and this should be fine for 250 shot of N20, but that's as big as you will want to go for spray. Because i am not going to spray i opted for the 427 cubes with the 4.060 overbore.

And yes, you can still go with very big hyd. cam on your stroker and still spray the **** out of it. Many of the MTI 422s that have pushed LS1s into the 9s on spray, utilize the S1 cam (same one i'm going with) with big specs of 244/244, .612 lift on 112 lsa!

Good luck.

MTI 427 C5 Roadster <img border="0" alt="[Fluffy]" title="" src="graemlins/fluffy.gif" />

<small>[ December 01, 2002, 09:47 PM: Message edited by: MTI 427 C5 Roadster ]</small>

 

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by MTI 427 C5 Roadster:
<strong> With a 4.125 crank and an overbore of 4.035 you would get 422 cubes and this should be fine for 250 shot of N20, but that's as big as you will want to go for spray.

</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Why does 250 seem to be as far as anyone is going?
Does that mean I can spray 300-400 on the 409?
<img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />

 

Dave,
Because 250 is enough. <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" /> Hope to see you spray a 300-400. That would be awesome to see. <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

 

Folks have sprayed 300-400 on big strokers it's a bit tricky.

 

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Pro Stock John:
<strong>Folks have sprayed 300-400 on big strokers it's a bit tricky.</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Can you explain tricky? <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />
Was it in the progression of the shot or how they built their motor?

 

its tricky getting your AF ratios just right so you dont burn plugs on every pass or worst yet your pistons. this is because most systems usually run pretty lean to gain those numbers which means that you have to make sure your N2O and fuel pressures are absolutly perfect. with a smaller shot you have some leeway so it is easyier to tune. i also hope you dont plan on spraying that through the intake.

 

you can get the F.A.S.T. computer and tune for each cylinder. i beleive now they have where you can change the timing every 50 rpms <img border="0" title="" alt="[Eek!]" src="gr_eek2.gif" /> and you can tune on each individual cyliner. but after that, you will need to worry about gettin the car to hook up.

 

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by taqwache:
<strong> i also hope you dont plan on spraying that through the intake.</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">No it would be direct port.
As for N2O programming, that will be resolved hopefully in a month or so.
This particular unit allows for tuning as you mentioned and is very user friendly.
Thanks for replyin, I think I'm treading close to being a nitrous thread so I'll kill it off.
Just one last thing, it seems most of our cars start to richen up at the end of a run, so by delaying the shot, A/F would be adequate.
The controller I will have should be able to compensate, I guess that's why they call it TNT.

 

hehe ARE has sprayed a lot more than 300 <img border="0" alt="[devil]" title="" src="graemlins/gr_devil.gif" />

 

Gentleman here semi lcoal to me has sprayed about 300 on his LS1... obviously a built motor, but he sprayed into the 9's with a mildly build motor <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />

 

"hehe ARE has sprayed a lot more than 300"

With a resleeved aluminum block <img border="0" title="" alt="[Eek!]" src="gr_eek2.gif" /> <img border="0" alt="[Fluffy]" title="" src="graemlins/fluffy.gif" />

 

ARE has sprayed 200-300 a number of times with some of their cars.

You need a serious fuel system to support a 300 shot fogger. Please research that otherwise you can't support 650-700rwhp.

Might want to look into using a progressive controller if you are not sure you can hook 300-400 nitrous.

 

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Pro Stock John:
<strong>

You need a serious fuel system to support a 300 shot fogger. Please research that otherwise you can't support 650-700rwhp.

Might want to look into using a progressive controller if you are not sure you can hook 300-400 nitrous.</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Most definitely agree on the fuel system.

I've already got the controller in mind after visiting the SEMA show here.
It's still being prototyped, but it should be ready here in a few weeks according to them.
I could've swore there was a dude in Colorado spraying 300 on something, not sure if it was an Lt-1 or an Ls-1 though.
If he can accomplish that in the air conditions he has to endure, I should be able to overcome my setup with careful planning.
Before I forget again, can someone explain offest grind on the crank?

 

The fuel system is definately key. You cant have a drop in volume once the juice starts flowing. If you do, its <img border="0" alt="[kaboom]" title="" src="graemlins/gr_bomb.gif" /> Tuning is just as important.l

 

I disagree with one of the roadster's observations. The 4.06 bore should be able to take all of the NOS a sane person can throw at it, and more. For example, how many have actually busted the cylinder wall in a 4.06 bore CI block?

 

Stealth,

you are probably right about the 4.060 bore being able to handle healthy doses of spay and i hope you are right so i always have that option in the future (after warranty expires, etc). I am just going on with several tuners told me, that being "if your going to spray hard then i wouldn't go over a 4.04 bore (just as a precautionary type mearure)." Jayson at MTI did tell me however, that i should have no problem should i ever want to spay up to 100 to 150 with the 4.060 bore.

THat being the case, your probably right that the 4.060 bore can handle healthy doses of spray! <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />

MTI 427 Roadster