LS Engines

[Matt49]

Aside from the major sanctions not allowing the coil packs, what is keeping people away from building these engines. With all of the aftermarket parts available for them now, it looks like a guy could build about 700HP for less than $15K and that's with quality bottom-end stuff.
Then there are obvious workarounds to the coil packs but I've heard of mixed results on the conversions (sloppy timing, reliability issues, etc.).
Other than that, why aren't we seeing more of these motors? Or are they out there and I'm just not looking close enough?

[Krooser]

Why no modern Hemi's? Two spark plugs? The second plug fires AFTER TDC to clean up emissions. They make 3-5 HP more with the second plug but can run one on plug, too.

MSD makes a box for them.... they only run 20 degrees advance.

700HP is available with an hydraulic cam, Arrow intake, MSD box. 390HP from a 5.7 out of the box.

The Apache heads ('09-up) will flow 400 cfm. You can buy parts from the Dodge dealer.

I bought a 2014 5.7 with a scored piston. Piston, rod and rings were $150.00 from Mopar. Add a $550 intake, $300 camshaft and a $550 MSD box and you have a nice 600-650 HP motor.

[Jking24]

They had a run around my way for a bit in the modifieds but they don't seem to have the drivability that a traditional sbc has. I think the head's are too big. The guys that had them around here were boasting 700+ numbers but being out run by all steel 358s.

[Matt49]

They had a run around my way for a bit in the modifieds but they don't seem to have the drivability that a traditional sbc has. I think the head's are too big. The guys that had them around here were boasting 700+ numbers but being out run by all steel 358s.

I could see that. Even the stock heads have serious flow numbers. How long ago was this? I'm wondering if some of the higher quality aftermarket heads (AFR, Trickflow, etc.) have found some better combinations with cams that can make 700HP without huge torque spikes. I could be wrong but I think the drive-ability is all about a broad, smooth (and even flat) torque curve.

[Jking24]

I could see that. Even the stock heads have serious flow numbers. How long ago was this? I'm wondering if some of the higher quality aftermarket heads (AFR, Trickflow, etc.) have found some better combinations with cams that can make 700HP without huge torque spikes. I could be wrong but I think the drive-ability is all about a broad, smooth (and even flat) torque curve.

This was last year and i think the heads are just to big to work well with a carburetor their is no air speed. Also rpm is a issue and to start turning those things harder you need solid cams and adjustable valve train and to do that on a ls that 15000 number goes out the window quick. The guy that was/ is building them around here had one in bloomquist car i think the year before last for some testing. I think their was a article in circles track or one of the magazines on it . But ui don't think they ever raced it just tested and im guessing it wasn't better. We also had a few super guys run them several years ago now but ls motors loose all their advantages when you get on the open platform.

[Hi-Line BRC]

We are running an LSX7 in a North East Dirt Mod. Current HP is @ 805HP/795torq at 6700 (Uncorrected), HP/Torque curve is crazy. not some spike, very driveable. This is with a set Mast Motorsports Heads. (He has a 850ish HP version too, i forget what heads it uses on this version) We run it under 7500 rpm. This is a dart block, carb setup, with a mechanical fuel pump, mag and dry sump. The only people who have a problem with this 28k engine is the sanctions that get kick backs and the engine builders selling 60k engines.

[riddle28]

the oiling system isnt ideal for sustained high rpm's, it doesnt oil the crank first

[MasterSbilt_Racer]

the oiling system isnt ideal for sustained high rpm's, it doesnt oil the crank first

When a traditional sbc is plumbed pressure in the front, does it oil the crank first?

[Krooser]

Priority oiling can be achieved with an external oil line tapped into the block to redirect the oil to the main gallery...it's an old Indian trick.

[Kromulous]

I talked to a Engine Builder out on NY i think, and he was pretty confident in 840-850 hp.

Also heard that the oil guys are trying to run in these Engines are wrong, there designed for 0w-20 etc, not 20w-50 etc. The thick oil is not helping the oil system.

Sounds like Krooser may be on to something thou...

I think they will catch on, but as with a lot of things people stick with what they know.

[Matt49]

I think most of the aftermarket blocks (LS or SBC) have addressed this issue.

[billetbirdcage]

I guess it all depends on where and what type of shows your racing at.

If you are racing bigger shows on tracks that will have traction early, then it takes so much motor and RPM's now a days that if you build a LS like the stuff we running now it can't be much cheaper once you get to that power level and RPM and make it survive.

Why do you think you see so many engine failures lately....9300 RPM with 4" stroke 900HP+ and we could have used more this past weekend.

[Kromulous]

LOL That’s insane.

[fastford]

Priority oiling can be achieved with an external oil line tapped into the block to redirect the oil to the main gallery...it's an old Indian trick.

you brought back a memory krooser , we did that to a 351 clevland back in the early 90s on a limited engine , rear mains would last all season then......

[let-r-eat]

They are running LS engines already.......................... Roush Yates Fords!


I had to put that on there for fastford.

[Jking24]

I guess it all depends on where and what type of shows your racing at.If you are racing bigger shows on tracks that will have traction early, then it takes so much motor and RPM's now a days that if you build a LS like the stuff we running now it can't be much cheaper once you get to that power level and RPM and make it survive.Why do you think you see so many engine failures lately....9300 RPM with 4" stroke 900HP+ and we could have used more this past weekend.

I don't think most people know what rpm does to help a dirt latemodel through the corner. You can claim all the numbers you want but 9 out of 10 times if your turning 3500 rpm mid corner and im turning 4500+ I'm gonna be better in that corner. And im not talking about spinning tires

[MasterSbilt_Racer]

I don't think most people know what rpm does to help a dirt latemodel through the corner. You can claim all the numbers you want but 9 out of 10 times if your turning 3500 rpm mid corner and im turning 4500+ I'm gonna be better in that corner. And im not talking about spinning tires

You got a lot more engine braking.

[fastford]

They are running LS engines already.......................... Roush Yates Fords!


I had to put that on there for fastford.

haha , i would argue the ls was derived from copying a ford , with the equal spaced ports and all.....

[Doc88D]

Baldwin race engines has addressed the oiling issues in their LS engines. They are making hi 850-900HP in their LS Late Model stuff. They also do a bunch of Mod stuff and even have a 410 LS Sprint car engine. They have feature wins in all three divisions.

[hucktyson]

What builder is suggesting to twist your 4” stroke 9300 rpm ???? Parts manufactures probably love that astronomical piston speed ...