Stock Block question

[BlackLight]

Well my question is kinda directed in the direction of how much the stock block will hold. I bought Ron's 2.3 KB a while back and its got the 3.1 RR on there and I've got an 8# lower sittin here, but I keep gettin the urge to order a 2.75" KB upper :evil. Something tells me the stock block/rods wont last too long with that combo...what do you guys say?


on the other hand...I found a Prime One rods/ Manley Pistons/Plasma Moly rings set on ebay for 988....damn you ebay!!!!!!!

[slick-svt]

Might live a little longer with a 4 on the bottom

[Sixpipes]

8#/2.75 combo is asking for trouble. :cool:

[Silver_2000]

Might live a little longer with a 4 on the bottom
Remove the word MIGHT ...

+1

[Ohmsby]

Remove the word MIGHT ...

+1
+1 more

[FRDRCING]

I would sell the 6# lower or take it off till you got a built block to handle that kind of power. If it's got the 3.1 upper on it, then I would look for a 4# or even a 2# lower. The 6# lower on there with the 3.1 on the KB is going to go Kaboom even with a good tune it will be just a ticking time bomb.

[Mark #2]

I would sell the 6# lower or take it off till you got a built block to handle that kind of power. If it's got the 3.1 upper on it, then I would look for a 4# or even a 2# lower. The 6# lower on there with the 3.1 on the KB is going to go Kaboom even with a good tune it will be just a ticking time bomb.

It is pushing it, do not put the 8 lb lower on
9" lower and 3" upper is the most you can run on a stock block with race gas.
3.25" upper 9" lower for pump gas

[Ohmsby]

It is pushing it, do not put the 8 lb lower on
9" lower and 3" upper is the most you can run on a stock block with race gas.
3.25" upper 9" lower for pump gas

and unless I am mistaken this gentleman owns the fastest longest living stock block in our club.... so he speaks the truth

[BlackLight]

Haha well! Ill take the 3.1 off there and put the 3.25kb on, as I wont have money to build the block till this summer prolly.

[TXLIGHTNING]

I'm running the same blower on my stock block, I have a 3.25 upper and a 4# lower making 12-13#'s of boost :tu:.

[wesman]

8#/2.75 combo is asking for trouble. :cool:

He speaks from experience.....keep it under 15 psi on the stock block on the street.

--wes

[BlackLight]

I'm running the same blower on my stock block, I have a 3.25 upper and a 4# lower making 12-13#'s of boost :tu:.


Just out of curiosity, what kind of times are you running with that setup?

[TXLIGHTNING]

Just out of curiosity, what kind of times are you running with that setup? Just had it installed 2 weeks ago, I don't know yet.

[BlackLight]

Just had it installed 2 weeks ago, I don't know yet.

Ah, ok...well let me know when you get dyno numbers/ times on that thing. Thanks man! :beer:

[L8 APEX]

You will need fuel pumps, injectors and mass air meter to run that much noise. An 8# lower and 2.75 upper is worth about 23lbs of boost on a stock block heads, cams, exhaust etc.. A 2.75 on a stock pulley is good for 15psi. a 3" upper and 9" lower is about 18-20psi. Remember with stock cams, heads, and exhaust you have a lot more back pressure and less flow than a built motor. Heads, cams and exhaust bleed off a lot of boost with their imporved flow.

[BlackLight]

You will need fuel pumps, injectors and mass air meter to run that much noise. An 8# lower and 2.75 upper is worth about 23lbs of boost on a stock block heads, cams, exhaust etc.. A 2.75 on a stock pulley is good for 15psi. a 3" upper and 9" lower is about 18-20psi. Remember with stock cams, heads, and exhaust you have a lot more back pressure and less flow than a built motor. Heads, cams and exhaust bleed off a lot of boost with their imporved flow.

Ive got 60# injectors and walbros 255lph dual fp kit that are gonna be installed along with the blower, theyre sittin in my room right now, and the truck already has a 90mm MAF, and I've got a Silver bullet exhaust/kooks longs on the truck. I think I can live with the 6# lower and 3.25 upper for now...this summer will be my engine build tho, heads, cams, pistons, rods, etc. Ill be back in texas for that, and I'm lookin for someone to do the install :D

[L8 APEX]

You need an SCT or other calibrated MAF the stock MAF is not enough...

[BlackLight]

You need an SCT or other calibrated MAF the stock MAF is not enough...

Like SCT's Big Air maf? a friend of mine has his for sale.

[99WhiteBeast]

Like SCT's Big Air maf? a friend of mine has his for sale.

Or a MAFIA extender

[WA 2 FST]

Just out of curiosity, what kind of times are you running with that setup?

I have the same setup (3.25" upper, 4# lower) and I see the same 13-14psi. HP/TQ #s are in sig. This is on 93 octane/10% ethanol fuel.

On a stock block all my research showed ~470-480rwhp is about as far as you want to go if you want it to live a long, long time. Mark #2 is obviously way above that...there are exceptions to the rule. Also, an important factor is tranny life.

If I were to go more radical than I am now, I would definitely build a block and a trans.

[wesman]

I have the same setup (3.25" upper, 4# lower) and I see the same 13-14psi. HP/TQ #s are in sig. This is on 93 octane/10% ethanol fuel.

On a stock block all my research showed ~470-480rwhp is about as far as you want to go if you want it to live a long, long time. Mark #2 is obviously way above that...there are exceptions to the rule. Also, an important factor is tranny life.

If I were to go more radical than I am now, I would definitely build a block and a trans.

It also matters what you run on the street. Mark doesn't run 18 psi on the street, he saves that for race day on good fuel (104+). His street tune is much more conservative and I don't think he goes on those spirited highway runs that I've seen most stock blocked L's die on.

It's all in the tune and the way you drive it up to a point.....but you are definitely right on the mechanical limits being in the high 400's range.

--wes

[WA 2 FST]

I agree... there's more to it than the #s I posted through my research. But for details and lots more opinions, one just needs to do a search on this forum and its all in there. :)

Given that I drive mine conservatively, with the power its making I think it should last a long time before going "boom". We'll see. Some engines are better than others.