: Can you LQ9 to 427?


Black LS2
07-31-2010, 07:23 AM
Hey guys! Thinking building forged 427 stroker out of LQ9. Working on the budget so looking for more economical way to do it. The car is DD so it has to be reliable and street friendly. Did searched but cant find the answers i am looking for. The goal is 550+ and 150 shut for some fun. I think my LS2 can be resleeved but its not cost effective and wont be as reliable. Does 6.0 iron block has more meat in it and longer cylinder bores so it doesn't have to be resleeved? What intake , heads and cam will take me closer to my goal? What rotating assembly? Can i transfer my ported fast90 or ? :scratch: Please any opinions and advice would be appreciated.Thanks.

batboy
07-31-2010, 07:43 AM
For all practical purposes, you need to use a LS3, LS7, or LSX block to make a 427 (or resleeve the LS2). I would not bore the 6.0 iron block out to more than 4.030" although I'm sure some have probably done it. You would need to bore it to 4.070" (I suppose you could have a machine shop sonic test your block to see if you have enough meat in the cylinder walls to do this, but it would require a 4.1" stroke). The other thing is if you plan on running boost or nitrous, any stroked crank over 4.00" will not give you much meat on the pistons between the ring landings and pin. While this might be fine for N/A, the extra pressure of nitrous or boost could cause problems. With the LQ9 iron block, go 408 forged stroker and up your shot to 200 or 250 hp, no problem

bozzhawg
07-31-2010, 07:47 AM
Hey guys! Thinking building forged 427 stroker out of LQ9. Working on the budget so looking for more economical way to do it. The car is DD so it has to be reliable and street friendly. Did searched but cant find the answers i am looking for. The goal is 550+ and 150 shut for some fun. I think my LS2 can be resleeved but its not cost effective and wont be as reliable. Does 6.0 iron block has more meat in it and longer cylinder bores so it doesn't have to be resleeved? What intake , heads and cam will take me closer to my goal? What rotating assembly? Can i transfer my ported fast90 or ? :scratch: Please any opinions and advice would be appreciated.Thanks.

It has been done before..... but there is always a price to pay....

I have seen em bored .060-.070 over I would suggest sonic testing though...

The 4.100- 4.125 crank is the nemisis.... It takes quite a bit of clearancing to get those cranks to fit...... some just do it, some say its not worth it.....

It would be easier with a L92/LS3 block vs a LQ4/LQ9 block

Raymond Luxury Yacht
07-31-2010, 07:59 AM
Can you do it with an L92? I don't know the specs of it, but it's a 6.2L block.

batboy
07-31-2010, 08:02 AM
Yes, it definitely can be done with a L92 block. Just order this rotating assembly from Texas Speed (see link).

http://www.texas-speed.com/shop/item.asp?itemid=1061&catid=88

If you plan on using over a 150 HP shot of nitrous or more than 10 psi of boost via forced induction, we recommend our TSP 418 cid L92/LS3. The 4.00" stroke will allow for lowered ring lands and a thicker piston top to take the abuse of power-adders.

Black LS2
07-31-2010, 08:05 AM
Thanks. How reliable a resleeved LS2 would be .What combo do i need to reach my goal. I thought that 4.000"stoke and 4.125 bore would net 427

batboy
07-31-2010, 08:14 AM
Done right, a resleeved LS2 is fine, lots in the racing scene. Yes, a 4.125" bore and 4.000" stroke will net you 427. Additionally, a 4.070" bore and 4.100" stroke will get you 427. Technically, a 4.060" bore and 4.125" stroke will too, but I haven't seen that rotating assembly offered (not to say it isn't available somewhere).

Oh4GTO
07-31-2010, 09:27 AM
You can get a 425 out of an LQ9. 4.06" bore with 4.1" stroke. Nothing out of the ordinary here. Just the block needs to be sonic tested.

CyCoe
07-31-2010, 06:47 PM
I would say stick with the tried and true 408.......lots of options, tons of them around. And much more economical with an iron block.

Black LS2
08-01-2010, 07:31 AM
You can get a 425 out of an LQ9. 4.06" bore with 4.1" stroke. Nothing out of the ordinary here. Just the block needs to be sonic tested.
Thanks for the info. What rotating assembly for 425? To be honest i never heard of 425.

batboy
08-01-2010, 08:03 AM
A few seconds of search google and I found that Eagle does make this rotating assembly. Again, you have to use a near perfect block that was sonic tested, you still have a lot of clearancing with that large of a stroke, and the pistons ring landings are narrow which means less strength for nitrous/boost. Think I'd rather order an Erl's sleeved block if I was going to do this.

GMH GTO
08-01-2010, 02:19 PM
I've seen 408 builds make just as much power as 427 long stroke deals, with same top end. The longer crank just peaks power sooner.

That 40X ci build is going to last longer too. Specially with a short sleeve like LQ9 blocks have, the long stroke 1.050" CH pistons rock in the cylinder at BDC, the skirts get beat up. Skirts are most important part of a piston.

Oh4GTO
08-01-2010, 04:59 PM
I had a 425ci LQ9 build in a vette. Made 525+/525+ with a crap tune and L92s and a mismatched cam. You will gain a lot of torque with the extra cubes. Remember thats what gets the car going.

Black LS2
08-02-2010, 04:18 PM
I had a 425ci LQ9 build in a vette. Made 525+/525+ with a crap tune and L92s and a mismatched cam. You will gain a lot of torque with the extra cubes. Remember thats what gets the car going.
Thanks for your opinions. Please keep them coming. I think i want to stick with larger cube block . What do you think about lsx376. What would be good way to budget build it to be close to my goal. Tanks again.

jcain
08-02-2010, 04:47 PM
416 lq9

Proth1975
08-03-2010, 12:27 PM
427 LQ9. Love it. PM me.

-P

txgtofan
08-03-2010, 03:48 PM
Done right, a resleeved LS2 is fine, lots in the racing scene. Yes, a 4.125" bore and 4.000" stroke will net you 427. Additionally, a 4.070" bore and 4.100" stroke will get you 427. Technically, a 4.060" bore and 4.125" stroke will too, but I haven't seen that rotating assembly offered (not to say it isn't available somewhere).

ERL: Resleeved LS2 Block 4.185 bore X 4.125 stroke = 454

When my short block gets tired!

bozzhawg
08-03-2010, 04:37 PM
ERL: Resleeved LS2 Block 4.185 bore X 4.125 stroke = 454

When my short block gets tired!

How much did those sleeves hit ya for?

fossilblue32
08-07-2010, 02:24 PM
I have heard of 427s doin alright with a stock bore, but doesnt seem to have the longevity needed, I personally think its to much stroke with that bore, thats the reason for me goin with the 416 ls3, I love my set up, made over 500hp and 475tq goin through 3.91s. I would try to stay square with the stroke and bore, 4.060 bore with 4.000 stroke with the Ls3

Proth1975
08-08-2010, 05:17 PM
I have heard of 427s doin alright with a stock bore, but doesnt seem to have the longevity needed, I personally think its to much stroke with that bore, thats the reason for me goin with the 416 ls3, I love my set up, made over 500hp and 475tq goin through 3.91s. I would try to stay square with the stroke and bore, 4.060 bore with 4.000 stroke with the Ls3

Peh... Plenty of LQ9 427s around. My engine builder felt it was the best setup, only reccomending the 418 if I was boosting.

Personally, you're worse off with an Alu block vs. a stroker.

My numbers are great, and that's on stock heads.

-P