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Conversion block?

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Old Sep 7, 2020 | 11:19 AM
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Default Conversion block?

Didn't somebody make a small chevy block that allowed LS heads? Anybody know anything about them? Or were they just another dumb idea?
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Old Sep 7, 2020 | 01:52 PM
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World made them, no idea if they are around. A 4" stroke and a nice LS3 head would rock.
If it took to a larger bore use an LS7 head that will make some steam

Last edited by cv67; Sep 7, 2020 at 01:53 PM.
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Old Sep 7, 2020 | 05:11 PM
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summit lists em $2500
https://www.summitracing.com/parts/w...SABEgJmqvD_BwE

unless you already have a hi-$ big-bore sbc rotating assembly, why not build a big-bore LS ?

don't hold me to it, but perhaps this conversion block has old-fashioned sbc caps instead of LS superior cross-bolted caps.
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Old Sep 7, 2020 | 05:55 PM
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Bet the block is pretty strong, looks like the gold plated price is too.
Can be bored to 4.200 which is a plus
It would make a fun build imo with a simple carb/distributor but not at that price.
Know the lsx is the trend but Id never put one in mind esp EFI. Ugly *** engines lol

Last edited by cv67; Sep 7, 2020 at 06:00 PM.
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Old Sep 9, 2020 | 04:00 PM
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Originally Posted by 7t9l82
Didn't somebody make a small chevy block that allowed LS heads? Anybody know anything about them? Or were they just another dumb idea?
I'd guess the aluminum heads on a ZZ4 will fit and also flow well???
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Old Sep 9, 2020 | 08:34 PM
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I really dont understand why someone hasn't developed a small block head that borrows heavily from the ls architecture. Unless they think existing stuff is good enough.
I know I can match the power of an ls but the driveability and fuel mileage would likely suffer.but then maybe it's in the electronic controls
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Old Sep 9, 2020 | 10:02 PM
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ZZ4 heads are same as on rpo L98 motor; they have small 58cc combustion chambers which can really help low compression dish-piston motors. However, they have relatively small intake ports and they don't flow as well as GM's iron Vortecs and do Not have the desirable fast-burn chamber design either.

ZZ4/L98 heads in stock form can support up to about 400hp. And they are No longer in production.
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Old Sep 9, 2020 | 10:09 PM
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compare contrast
production sbc heads have 23 degree valve angle; some very hi-po aftermarket sbc heads are 18 degrees.
production LS heads have max 15 degrees and some hi-po aftermarket heads have 11 degrees.
In general, the closer to vertical ( 0* ), the better the flow.
compared to sbc, the LS port & chamber architecture is on another planet

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Old Sep 9, 2020 | 10:33 PM
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There are 18 deg and smaller heads for Gen 1, spreadport stuff that makes big power
You may need different pistons, valvetrain stuff gets pricy quick. But they rip!


Then theres sb2.2 stuff, different ballgame all together

Last edited by cv67; Sep 9, 2020 at 10:35 PM.
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Old Sep 9, 2020 | 10:36 PM
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I don't see the point. i don't think there is that much difference between building a small block and a LS these days. Everyone complains about the LS being ugly, but a small block with LS top end would look very similar from a looking under the hood perspective. It could be argued the front end looks better, but you could get the same look from the heads, valve cover and intake area with an LS as you could get with this block.

The intake that fits between LS heads and allows a distributor sounds like a custom made piece.

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Old Sep 10, 2020 | 09:35 AM
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Totally agree with the ugly part seems silly to have to put a cover over the valve cover. This was just something I was wondering about doing, but I think I will stick to An engine I can fix on the side of the road.
I didn't know the LS had that good a valve angle, wow! This has been a great discussion.. except the zz4 idea lol. Thanks but I'm over 400 h.p already.
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Old Sep 10, 2020 | 03:20 PM
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https://billmitchellproducts.com/pro...on-w-ls-heads/
It does allow the use of all external bolt-on SBC Gen-1 components; such as MOTOR MOUNTS, block mounted fuel pump, oil pan, front cover, sbc gen-1 crankshaft with 2 pc seal,...etc.
Holds more coolant than a gen-1, has better crankcase windage than an LS, and a raised cam to boot ! Likely stronger than a factory LS block too.
I'm sure I've left out a little. Seems to solve some problems and allow less expensive Gen-1 components that alot of racers already own, while adding on the better heads and more !
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Old Sep 10, 2020 | 06:41 PM
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Justified compared to the cost of an LS conversion maybe?

the block and acessories bolt in. Headers are custom. Might be a cool swap. ???
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Old Sep 10, 2020 | 08:24 PM
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Definitely something to think about..
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Old Sep 10, 2020 | 08:42 PM
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Here's a thread from august about two sb2 or splayed valved SBC chevy engines for sale.
Somewhere around 900-1100Hp
Shairoff says a street tuned version could make 900 HP and be perfectly streetable!

https://www.corvetteforum.com/forums/c3-tech-performance/4429177-saw-1100-hp-smallblock-chevy-today.html

https://www.chevrolet.com/performance-parts/components/engine/small-block/splayed-valve-aluminum-race-cylinder-heads




Yes this is a SBC head. GM even. Non siamized exhaust, canted valves, not inline. This is the splayed valve, not the SB2.

Last edited by leigh1322; Sep 11, 2020 at 03:05 PM.
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Old Sep 10, 2020 | 10:01 PM
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mseven had a 441ci sb2.2, made around 725/6xx tq,, hyd roller cam very driveable.
That will embarass almost everything youd come across
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Old Sep 10, 2020 | 11:06 PM
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many dirt late models run chevy SB2.2 and ford RY45.
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Old Sep 11, 2020 | 06:02 AM
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Dart made a head several years ago based on the Buick Stage 2 V6 ports.
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Old Sep 11, 2020 | 10:17 AM
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Originally Posted by stingr69
Justified compared to the cost of an LS conversion maybe?

the block and acessories bolt in. Headers are custom. Might be a cool swap. ???
Block is same height as a reg LS and you could use normal LS swap headers.
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