Mopar Jimmy

I have been told by a very reputable racing enjine builder, that he can bore to .060 overbore the LQ9 6.0 liter iron block engine and coupled with a lunati forger stroker crankshaft, 4.125 stroke, (2.1 journal size, std/std radiused and deburred oil passages) that this would make for 427 Cubic Inches and would be bulletproof, for highpower NATURALLY ASPIRATED, application. (No N20 or forced induction to ever be used on this stoker).

Is this accurate that this enjine would be 427 cubes? and would boring to .060 overbore for naturally aspirated application on the LQ9 iron block be 100% safe? If not, what is the most you would overbore this block to without jeopardizing any reliability and what are the biggest cubes that could be made with the Lunati 4.125 crank?

Thanks,

Nitrovette :smash:


[Modified by Nitrovette, 10:36 AM 9/8/2002]

Austrian Vette

Don´t know about the specs.
But who want´s to stay naturally aspirated :lol:

Michael

Mopar Jimmy

I would love to build a 427CI, mid to high 10 second consistent, reliaible, "bullet proof" naturally aspirated SUPER STROKER. Not all of us are into the N20 or any poweradders for that matter) and i think that the above enjine/C5 would be AWESOME!:D

Nitrovette :smash:


[Modified by Nitrovette, 2:48 PM 9/8/2002]

Mopar Jimmy

Come on where our all of the super stroker experts, Kewlbreez, Matt G, RWJ 383, Godspeed, etc.? :confused:

Nitro

66ImpalaLT1

Talk to Pro Stock John on LS1Tech.com, I believe he has a .060+ LQ9 iron block.

Eric

Mopar Jimmy

This set up=427 cubes, correct.

Nitrovette

Skeeter1

I have the same block and wanted to go .60 but stayed on the safe side and went .30 to make a 422, of course this application is used with 200 shot of nitrous sometimes

Mopar Jimmy

if i don't spray i would be fine correct? Skeeter, are you using 4.125 super stroker crank with the 6.0 liter ironblock to produce 422 cubes?

thanks,

Nitro

Wt99C5

Nitro,
here's a displacement calculator, you'll need the bore diameter. http://fast.race-cars.net/calculator...alculator.html

I've been looking at this stroker kit, http://www.holley.com/HiOctn/ProdLin...KA/Chevy1.html
But your plan looks more interesting.
Where did you find the crank, rods and pistons ?

Skeeter1

yes, and it took almost a year to get from lunati

0Sales@MVPAutoParts.com

:lol: :lol: :lol:

Jayson @ MTI is building me a similar motor, but it's for nitrous application instead of NA. We are sticking to .030 and a 4.00" stroke crank, so the it will be a 408 motor. :cheers:

415cid Goose

I went .060 on my 415cid.

Redline Motorsports

A LQ9 can safely be punched .060" over. I am also in the middle of a stroker project. I was going to also build a 422 but decided to build a 418 usings a 4.080" bore and a 4.00" stroke. Those longer then 4.00" stroke cranks are a real pain the rear when it comes to block clearancing and balancing. Its bad enough that the intake manifolds can't handle most of the cam/head setups let alone big displacement. If you want to run mid to high tens then all you need is 415-418 ci. You can make 530-540 RWHP.

What size rods are you guys using??

Austrian Vette

For a naturally aspirated use I would not go iron block (my personal opinion!).
I would save the weight and buy an LS6 block to do the strocker magic.

Michael


[Modified by Austrian Vette, 3:50 PM 9/9/2002]

MattG

Well, here is my opinion... I know your MAIN reason for building this motor is DRAG RACING and limited street driving...

Weight is VERY important for dragracing... And you would be adding 80-90lbs at least due to this steel block and for no real reason other than to save the money of a resleeved block. I could see if you had plans of a big shot of nitrous in the future, because then the extra strength of the steel block may come in handy, but I know you plan on keeping it natural.. I don't know exactly what the cost of a bored lq9 block is, but a resleeved LS1 block is around $2000-2200 depending what you buy with it, etc.. If you went with a resleeve you could go with quite a bit more bore, which we all know also helps out greatly for power, which gets you down the track quicker. The bigger the bore, the more unshrouded your valves are as well. Sure you are getting 427ci out of the LQ9 block with a 4.060 bore (which is pushing it to the limit in my opinion) and the 4.125" crank but the stroke from the crank is what is getting you a lot of these extra cubes.. Stroke is GREAT for torque, which is great on the street, and for roadracing and autocrossing but I think the 4.00" stroke crank would be better suited for a quicker and higher reving motor mainly used for running down the 1/4 mile.

So my opinion is save up the extra few bucks and go with a 422ci (4.00 stroke X 4.100 bore) resleeved aluminum and forget about the heavy lq9 block.





[Modified by MattG, 10:09 AM 9/9/2002]

Mopar Jimmy

Matt G:

I agree with you except i will take the extra 90lbs of the ironblock as a trade off for better piece of mind that a sleeve will never drop or have problems with enjine coolant leakage that more than a few folks on this forum and many of the f-body guys have suffered recently. I know ARE has great sucess with the resleeved aluminum LS1 blocks but i really want something that at least for my own piece of mind is extremely reliable and durable and would be better suited for N20 in case a throw a 150 shot to at least have the potential of havig a high 9 second street driven C5 on the spray and 10 second naturally aspirated.

WHen i see folks like that poor gentleman in one of the Saudi Countrys who is having major problems with his recently built 422 resleeved super stroker (Sleeve dropped and major coolant leaking into cylinders, etc.) that takes away my comfort level as far as reliabiltiy and problems! :U I want to be able to beat the **** out of this enjine without worrying about the type of crap that he is dealing with. THat being said i think a 415 to 422 ironblock would be perfect for me.:D

WHat cubes would be made by going with a .060 overbore on the LQ9 with 4.0 stroker crank? Would this set up make a better drag racer than going with the 4.125 crank (427 cubes)?

Nitrovette:D


[Modified by Nitrovette, 10:23 AM 9/9/2002]


[Modified by Nitrovette, 10:27 AM 9/9/2002]


[Modified by Nitrovette, 10:28 AM 9/9/2002]

MattG

That weight trade-off is up to you... But also remember you are giving up not only weight, but quite a bit of extra bore when you go with the steel block. I think 4.060 is too much bore for this block, especially if you want to leave enough strength for future nitrous, or even to refresh the engine someday in the future.

I know there has been some issues with resleeves in the past but to the best of my knowledge ARE has not had a problem with any of their resleeved blocks for over a year now and I know they build tons of them.

Like I mentioned though, even if you go the steel route, I would probably go with the 4.00" crank for your application because I know that 1/4 mile is your top priority.. You don't want an oversquare motor (more stroke than bore) for a dragracing engine that you want to rev as high and quickly as possible. I think a 408 is all you will get safely out of a 4.00" crank and LQ9 block.

Mopar Jimmy

Great points Matt G. YOu know I always truly value you knowledge and input. My bud, Intel 55, has pointed out the exact same thing to me about oversquared enjine and freshening up enjine therefore like you, recommending the .030 overbore vs. 060 for overall 408 or is it 409:D.

Since i don't care about emissions and don't mind addressing valve lash issue a couple of times a year, per intel 55's recommendation, i should just go ***** to the wall with a high revving, screaming, 408 ironblock stroker with radically agressive (yet still drivable) solid roller cam application. I would think with my converter and gears that should be good for mid 10 second times slips on motor only and about 500rwhp.:D WHat do you think?

Nitro





[Modified by Nitrovette, 11:28 AM 9/9/2002]

MattG

Solid roller isn't a bad idea.. That way you can run a huge arsed cam and keep it fairly streetable.. The only thing is the price of those adjustable jesel rockers that you need for the solid roller...

I do have a feeling after a year or so you will be squirting this motor though! :yesnod: :lol: :lol:

0Sales@MVPAutoParts.com

Just curious if anyone happens to know how big of a difference, in term or rwhp and rwtq, between the 408 and 427 (on 6.0L iron block, 4.03 X 4.00 versus 4.06 X 4.125)???

For me, it is not going to matter much because I'm going to spray the hell out of it. Whatever rwhp/tq I loose on motor going with the smaller 408, I just make it up on the pill size.:D:D:D

:cheers:
-Tuan