mebuildit

As the title says, I am wanting to build a LSx 427 dry sump, N/A engine.
Is it better to use an LS7 block? or another LS block with an external dry sump pump?

Lunati Crank
Lunati rods
Weisco Pistons
PRC or WCCH heads
11:1 comp
Jesel
Solid roller
Marcella intake

Steve - Race Eng

iTrader: (1)

I'm not sure if you are asking about the dry sump or what block to use to build a 427.

The GM dry sump as used on the LS7 is not block specific. The LS7 crank has a longer snout to accept the two stage oil pump and front cover. In other words, you can convert an LS2, LS3, etc. to dry sump by using a long snout crank and the other LS7 oil pump pieces.

If you already have a standard snout crank you can either get rid of it and buy a long snout crank or keep it and go with an external dry sump set up.

For race only use a multi stage external dry sump pump would be better.

As far as blocks go, for NA use you can go with the LS7, one of my sleeved LS2 blocks or an LS3 with a longer stroke.

Steve

mebuildit

Yes, I probably should of been a little more clear. I'm starting from scratch and would like to build a 427 that is dry sumped. The question that I had is which block would be best suited for this? I'm going to be using this in an off road buggy, so reliability is firstmost.
Now I don't mind spending the extra cash on something that will last. I just don't know which block is best suited for this combo that I'm looking at.

thanks for the advise.

Mike454SS

iTrader: (4)

Any block will accept GM or aftermarket dry sump systems...the LS7/LS9 stuff literally bolts right on to iron truck blocks, LS1 blocks, LS6, LS2...you name it. I've got an LS7 pan and pump on the bottom of my Iron 370 I'm building...yes my crank does have a longer "snout" or "post" or..."front part that sticks out past the first main cap".

I would say, if you want the best overall oiling system though, the Gen 4 blocks that can accept oil squirters (LS9 I think, not sure what others) for the undersides of the pistons are a pretty sweet setup...thats the only thing I can see as beneficial to any block in terms of the oiling system as like has been said, if a dry sump fits one gen 3 or gen 4 block, it should fit them all without issue,

LS6427

iTrader: (2)

Any way to do a dry sump on an LS6 blocked engine without the longer snout crank?

.

COPO9560

For reliability, do some research on Darton Sleeves in an LS1 block. While not cheap, appears a very solid foundation for big power in aluminum block. Not sure how well this would work out with dry sump stuff though.

wadd

sure, you can drysump any LSX block w/o the longer crank snout. You just have to run an external pump off a drive belt. It'll require a different damper, usually one with a Gilmer drive. You also need a drysump pan, which can be a modified wet sump pan, but if you are going to the expense, probably a purpose built drysump pan.

The next decision is whether you want to run an external pump for pressure and do away with the standard gerotor pump, or just use the external pump for scavenging only.

Either way, you are looking at some $$. Probably $2500 minimum, closer to 3K or 3.5K.

gnx7

iTrader: (28)

since it sounds like you are building an all out race setup with solid roller and dry sump oiling.... meaning dedicated track motor.

You should also look at increasing your compression ratio. Maybe even run E85 as it is cheap and effective. 13:1 or more compression (ask your engine builder)

A hydraulic roller will rev to 7200-7400rpm and not require any valve adjustments. The solid on the other hand will rev higher but needs periodic valve adjustments. If you want simplicity and set it and forget it.... then stick with the hydraulic roller. Production intakes won't support the powerband a solid roller can spin to anyway (ie LS7 factory intake even when fully ported)

mebuildit

I'm building this engine for my desert buggy. So that is why I like the dry sump. As for going with solid rollers, I don't mind running the valves, it makes me check things out better than oh, I'll check it next time thinking.
I don't mind spending the extra cash, as long as I have a solid powertrain. I am just looking for the best LS block to use. I don't know if a LS2 is better than a LS3 or 7? Which block holds up better to these types of mods?
As for me running E85, probably not gonna happen. I just want to run pump gas and forget about it. Remember, (K.I.S.S) Keep it simple.

Thanks for the helpful information guys. Keep it coming.

Steve - Race Eng

iTrader: (1)

Now that I know you are putting the engine in a buggy, check out Dailey Engineering for pans and dry sump pumps:http://www.daileyengineering.com/ls_engines.htm

Their oil pumps bolt directly to the pan eliminating any external scavenge lines.

The LS1 will need MID liners to get to 427". LS2 can be sleeved with dry liners or MID. With twin turbo buggies, I have these blocks making 900+ to the wheels with dry liners. I have several dry sleeved LS2 blocks running in the desert and short course races as well.

The LS3 is similar to the LS2 in block construction but with a larger bore. This block can also be sleeved with dry or MID liners.

The LS7 adds doweled steel main caps. You can use this block as is if you are careful with your build and tune. They tend to crack cylinder 7 if they get into detonation. I have three cracked customer LS7 blocks here to repair at the moment. It is easier to dry liner the LS7 before it cracks. Some cracked blocks can only be saved with MID liners.

The LS7 MID is probably the best alternative. You get steel main caps and the MID liners which will stay rounder in service than any dry liner block, new or resleeved. Daznio Performance is running one of my LS7 MID blocks in his class 1 desert race buggy. Several thousand hard race miles and the bores are staying dead round even though it has seen 265 degrees of coolant temp. www.danzioperformance.com to check out his videos.

Steve