LS9 heads on to LS2 block?

LS9 heads on to LS2 block?

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MyM8V8

Original Poster:

9,456 posts

194 months

Monday 27th April 2015
quotequote all
Just researching this as they appear good value. Only problem is that LS9's have 12mm head studs and the LS2 are 11mm.

Anyone have a view on whether this is possible?

SturdyHSV

10,083 posts

166 months

Monday 27th April 2015
quotequote all
This place seems to think it's possible, but mentions the same 11mm vs 12mm as you have

http://my.prostreetonline.com/2013/10/07/faq-what-...


stevieturbo

17,229 posts

246 months

Monday 27th April 2015
quotequote all
MyM8V8 said:
Just researching this as they appear good value. Only problem is that LS9's have 12mm head studs and the LS2 are 11mm.

Anyone have a view on whether this is possible?
Larger hole wont present a problem.

Worst case if there was a large discrepancy between fastener top and the hole, a suitable washer may be needed.

ARAF

20,759 posts

222 months

Monday 27th April 2015
quotequote all
stevieturbo said:
MyM8V8 said:
Just researching this as they appear good value. Only problem is that LS9's have 12mm head studs and the LS2 are 11mm.

Anyone have a view on whether this is possible?
Larger hole wont present a problem.

Worst case if there was a large discrepancy between fastener top and the hole, a suitable washer may be needed.
Maybe drilling the heads and block for a couple of locating dowels would be an idea though.

wormus

14,509 posts

202 months

Monday 27th April 2015
quotequote all
Get some ported LSA heads instead.

IIRC they are made from the same material and the same casting method. Same swirly things in the intake runners and only difference is the 1mm bigger stud size.

I got some from Ligenfelter. In hindsight I'm not sure the porting does anything to an FI engine except add cost. smile

Edited by wormus on Monday 27th April 20:18

stevieturbo

17,229 posts

246 months

Monday 27th April 2015
quotequote all
ARAF said:
Maybe drilling the heads and block for a couple of locating dowels would be an idea though.
Heads/block will already have locating dowels, and fairly sure these havent changed in diameter anyway

gsd2000

11,515 posts

182 months

Monday 27th April 2015
quotequote all
wormus said:
Get some ported LSA heads instead.

IIRC they are made from the same material and the same casting method. Same swirly things in the intake runners and only difference is the 1mm bigger stud size.

I got some from Ligenfelter. In hindsight I'm not sure the porting does anything to an FI engine except add cost. smile

Edited by wormus on Monday 27th April 20:18
Porting definitely helps but depends on the power adder, displacement and required rpm

The ls9 heads are alot nicer than the lsa heads for the same sort of money if not less

ArnieVXR

2,449 posts

182 months

Monday 27th April 2015
quotequote all
Only one way to find out smash

Or you could try the LS3 CNC ported heads, which probably flow the same and cost less. Allegedly weaker, but I'd imagine the extra strengthening is irrelevant. True, the LS9 has some cool valves.

minime68

399 posts

134 months

Tuesday 28th April 2015
quotequote all
LSA and LS9 are the same aluminum casting. The valves are different but if you are upgrading then there isn't much to look at. You can probably find a used set of LSA heads for $6-800 and then have them ported.

wormus

14,509 posts

202 months

Tuesday 28th April 2015
quotequote all
minime68 said:
LSA and LS9 are the same aluminum casting. The valves are different but if you are upgrading then there isn't much to look at. You can probably find a used set of LSA heads for $6-800 and then have them ported.
Exactly my point....and they will fit an LS2.

Given you will probably want to upgrade the valve springs at the same time, you might as well swap the valves out too. I went for inconel exhaust valves on mine.


Edited by wormus on Tuesday 28th April 12:18

MyM8V8

Original Poster:

9,456 posts

194 months

Tuesday 28th April 2015
quotequote all
minime68 said:
LSA and LS9 are the same aluminum casting. The valves are different but if you are upgrading then there isn't much to look at. You can probably find a used set of LSA heads for $6-800 and then have them ported.
No these heads I am looking at have the titanium valves and beehive springs fitted. They are only $890 a piece at the moment, so for a CNC ported head are cheap without the valves.

I also just found out that they will be OK with 11mm bolts.

ETA. Wonder if those beehive valve springs would be rated any good for FI?


Edited by MyM8V8 on Tuesday 28th April 12:32

Boosted LS1

21,167 posts

259 months

Tuesday 28th April 2015
quotequote all
MyM8V8 said:
ETA. Wonder if those beehive valve springs would be rated any good for FI?


Edited by MyM8V8 on Tuesday 28th April 12:32
I don't see why not if you keep the revs stock.

wormus

14,509 posts

202 months

Tuesday 28th April 2015
quotequote all
MyM8V8 said:
No these heads I am looking at have the titanium valves and beehive springs fitted. They are only $890 a piece at the moment, so for a CNC ported head are cheap without the valves.

I also just found out that they will be OK with 11mm bolts.

ETA. Wonder if those beehive valve springs would be rated any good for FI?


Edited by MyM8V8 on Tuesday 28th April 12:32
This is what Roger put in mine and they haven't broken yet even with 7k rpm and .629/.656 lift: http://www.lingenfelter.com/mm5/merchant.mvc?Scree...

gsd2000

11,515 posts

182 months

Tuesday 28th April 2015
quotequote all
MyM8V8 said:
minime68 said:
LSA and LS9 are the same aluminum casting. The valves are different but if you are upgrading then there isn't much to look at. You can probably find a used set of LSA heads for $6-800 and then have them ported.
No these heads I am looking at have the titanium valves and beehive springs fitted. They are only $890 a piece at the moment, so for a CNC ported head are cheap without the valves.

I also just found out that they will be OK with 11mm bolts.

ETA. Wonder if those beehive valve springs would be rated any good for FI?


Edited by MyM8V8 on Tuesday 28th April 12:32
They are only rated to .570 inches of lift. For piece of mind with your uprated cam swap the springs

wormus

14,509 posts

202 months

Tuesday 28th April 2015
quotequote all
You may want to consider these as they come with springs and valves included: http://www.lingenfelter.com/mm5/merchant.mvc?Scree...

gsd2000

11,515 posts

182 months

Tuesday 28th April 2015
quotequote all
wormus said:
You may want to consider these as they come with springs and valves included: http://www.lingenfelter.com/mm5/merchant.mvc?Scree...
But the gm ported ls9 heads are $1400 cheaper and have better valves and thats including a decent set of single beehive springs.

The heads seem like a bargain gareth

wormus

14,509 posts

202 months

Tuesday 28th April 2015
quotequote all
gsd2000 said:
But the gm ported ls9 heads are $1400 cheaper and have better valves and thats including a decent set of single beehive springs.

The heads seem like a bargain gareth
Is there a link to these heads? Cheapest I can find is $1000 each.

https://sdparts.com/details/gm-performance-parts/1...

Cannot see how stock LS9 valves and springs are "better" than the LPE ones.




Edited by wormus on Tuesday 28th April 15:09

gsd2000

11,515 posts

182 months

Tuesday 28th April 2015
quotequote all
wormus said:
gsd2000 said:
But the gm ported ls9 heads are $1400 cheaper and have better valves and thats including a decent set of single beehive springs.

The heads seem like a bargain gareth
Is there a link to these heads? Cheapest I can find is $1000 each.

https://sdparts.com/details/gm-performance-parts/1...

Cannot see how stock LS9 valves and springs are "better" than the LPE ones.




Edited by wormus on Tuesday 28th April 15:09
LS9 heads come with lighter valves

minime68

399 posts

134 months

Wednesday 29th April 2015
quotequote all
I say find the right heads then drop $250 on a proper set of springs and seals. Not sure where I read up but some LS9 heads were having issues with the valve guides you may want to look into that.
Ain't nothing more heartbreaking than hearing a ticking sound then engine going quiet after dropping a valve.

MyM8V8

Original Poster:

9,456 posts

194 months

Wednesday 29th April 2015
quotequote all
http://www.jegs.com/i/Chevrolet+Performance/809/19...

These are the ones which Gurmeet pointed me in the direction of. Only issue for me is the limited lift of .570 with the fitted beehive springs.

Titanium valves and CNC for $890 a piece. What's the catch???