Lets dispell a few myths about the new LS1/6 powerplants

NataSS Inc · #1 (**permalink**) 09-30-2003, 02:20 PM

I have been following this board for a while now and am getting ready to purchase a cobra replica to put together. I am more than likely going to go the FFR route. My plan is to use a similar set up LS1 to the one that powers my Camaro. A cam and heads LS1 (more LS6 now) with all the bolt ons made 420rwhp and 400rwtq on a mild tune.

But one thing I have seen here is alot of misconceptions about the LS1/6 powerplant.

Oiling issues: this was a problem 98-00 motors. It can EASILY be fixed with a ported oil pump for about 120.00. I would recommend a ported oil pump on ANY motor that you plan on using. The extra oil pressure never hurts anything.

Differences between the LS1 and LS6:

The only differences between the LS1 and the LS6 is that the LS6 came with higher flowing heads and intake. The cam was also slightly larger than the LS1. The heads are the key though, you can get as much as 20 more HP out of a good set of ported LS6 heads than you can with a set of LS1's. the PCV system on the LS6 is also far superior to the LS1.

The LS1 heads are a direct decendant of the NASCAR 18 degree heads. The factory heads flow fairly impresive numbers right out of the box, put after a good port job they can flow insane amounts of air. My MTI Stage 2 LS6 heads flowed 317 @ .600, thats alot of air.

Cubic inches:
ALL LSx based powerplants are 346ci. I have seen some pretty crazy ci sizes get thrown around. the new LS7 motor that MAY be used in the C6 vettes will more than likely be a 6.0 litre motor.

There is the C5R block that comes from the factory with a 4.125 bore that was built specifically for the Corvette Le Mans cars. You can buy them through ANY GM dealership at the meager price of 8,000.00 and thats just the bare block!

You can however bore and stroke your block out as far as 46x but I dont recommend that unless your car is a trailor queen. The are a number of companies out there that can provide blocks that already have been bored out. 2 of the big ones are MTI and ARE.

There are a number of aftermarket comanies that specialize in LSx performance now. And they make some great products, but you do have to pay for them. LSx parts are far from cheap. You can figure paying around double for LSx parts over standard SBC/SBF parts.

The only real "weak link" in the LS1/6 motors is the connecting rod bolts. but for a street car that isnt going to see much abuse its not a concern. the factory crank shafts can handle as much as 600hp before seeing issues with them.

the biggest "choke" point in the motor has been the intake manifold, the newer LS6 intake did have some good improvements but guys going into the BIG hp numbers are even running out of air with the LS6 intake. A company called Fuel Air Spark Technology (F.A.S.T) has developed a modular intake manifold that is supposed to show huge gains above the LS6 intake all the way across the powerband. this intake will be available late NOV./DEC.

If your looking for "crate" engines, I would honestly suggest EBAY. You can find low milage LS1 motors for reletively cheap prices.

I could go on forever about these motors. They are by far probably the best and most advanced engines available today in a factory production car. And tuning them is easier than any other motor out there today. I am not the knowlege guru about these motors but I have had a few of them apart and done alot of playing/tuning with them.

Here is a link to my little race car. Hopefully very soon there wil be a LSx powered FFR cobra right next to it!
http://www.imagestation.com/album/?id=4291599213

Mr.Fixit · #2 (**permalink**) 09-30-2003, 02:24 PM

Interesting first post

NataSS Inc · #3 (**permalink**) 09-30-2003, 02:27 PM

Quote:

Originally posted by Mr.Fixit

Interesting first post

LOL! yeah, I didnt quite think about it being my first post. Anyways.....HOWDY GUYS!!!

I have been watching here for a while now and have seen a few questions come up about the LS1/6 motors and just thought I could try and help some of the guys that are already headed in that direction.

Mike Braddock · #4 (**permalink**) 09-30-2003, 03:36 PM

Nata,

This should be right up your alley

. A nice LT1 FFR :

http://members7.clubphoto.com/brian5...05/guest.phtml

Mike

Excaliber · #5 (**permalink**) 09-30-2003, 05:12 PM

Well them boys down under love those LS1 motors in their Cobra. But then again, like Dodge, they are "different"! Oh I can see the "logic" in going that route, but it still don't feel right having Chubby power in a Cobra.

Interesting points about the LSX series motors. Some people I hav talked to refer to them as being related to the original SBC (283-350). I don't think so, I think there so highly developed they are essentially a "new" motor design.

I got it!!! How about fabricating some Ford valve covers for it? You know a "replica" engine..........

Ernie

NataSS Inc · #6 (**permalink**) 10-01-2003, 10:18 AM

Quote:

Originally posted by Mike Braddock

Nata,

This should be right up your alley . A nice LT1 FFR :

http://members7.clubphoto.com/brian5...05/guest.phtml

Mike

I have seen that one before. Beauttiful job on putting that one together. The owner did a great job of making it look clean. I dont know if I would go the LT1 route but that one sure turned out good.

NataSS Inc · #7 (**permalink**) 10-01-2003, 10:24 AM

Quote:

Originally posted by Excaliber

Well them boys down under love those LS1 motors in their Cobra. But then again, like Dodge, they are "different"! Oh I can see the "logic" in going that route, but it still don't feel right having Chubby power in a Cobra.

Interesting points about the LSX series motors. Some people I hav talked to refer to them as being related to the original SBC (283-350). I don't think so, I think there so highly developed they are essentially a "new" motor design.

I got it!!! How about fabricating some Ford valve covers for it? You know a "replica" engine..........

Ernie

Yeah, I would agree with you. There isnt much in common with the original 350ci motors. If anyone has ever had a LSx apart they would know what I mean. taking one apart and especially putting it together takes more precision than most people would want to worry about.

Now fabricating the "cobra" valve covers........thats a good Idea!

dalola · #8 (**permalink**) 10-01-2003, 10:34 AM

By NataSS:

Quote:

They are by far probably the best and most advanced engines available today in a factory production car.

You know, it's great to have your favorites, and appreciate a product, but this statement is a bit optimistic. But of course, this is just my opinion, as this was yours.

Anyway, welcome to ClubCobra, and best of luck on your build.

~Dave

Mr.Fixit · #9 (**permalink**) 10-01-2003, 10:35 AM

Quote:

Originally posted by NataSS Inc

Yeah, I would agree with you. There isnt much in common with the original 350ci motors. If anyone has ever had a LSx apart they would know what I mean. taking one apart and especially putting it together takes more precision than most people would want to worry about.

Now fabricating the "cobra" valve covers........thats a good Idea!

I haven't had one apart, I still play with antiques mostly. What is the difference? I read 18 degree heads, but those can go on an old SBC. What are the differences?

NataSS Inc · #10 (**permalink**) 10-01-2003, 11:36 AM

Quote:

Originally posted by Mr.Fixit

I haven't had one apart, I still play with antiques mostly. What is the difference? I read 18 degree heads, but those can go on an old SBC. What are the differences?

The biggest difference is that the LSX series motors are "O" rings motors. You wont find a single paper or metal gasket on anything other than the heads. Having the right torque on EVERYTHING is imparitive. I.E. on an old SBC intake you can pretty much just throw it on and reef the bolts down and it will be fine. On the LSx intake that use rubber "O" rings everywhere the intake HAS to be torque in a specific pattern and a specific inch/lb and then done again a second time at a higher inch LB. If your off by 1 bolt in the pattern or a couple inch lbs the motor will never seal. the same for the TB, valley cover, water pump, and oil pan. They actually have a special tool kit that cost a stinkin arm and a leg just so you can properly put a motor together.

One of the major differences about the LSX heads is the intake port. the SBC intake ports are almost square, where as the LSx heads are thin and very tall. almost like a long rectangle standing on the short end. Here is a picture of my stock head, intake ports. My new heads have ports that are considerably larger. Wish I would have got a picture of those before I bolted them on, they are aweful purdy!

The port design makes for higher flow capabilites over a SBC head. the stock LS6 head makes use of a sodium filled valve to reduce valve train weight allowing for higher revs.

Mr.Fixit · #11 (**permalink**) 10-01-2003, 12:00 PM

O-ring instead of paper gaskets, yeah pretty much most newer motors do that. Intake ports on the heads, well, there are so many different aftermarket heads for SBC's, I didn't consider port shape to be a big difference in engine design. A SBC running dart "buick" heads is still a SBC. Valves, who runs factory valves anyhow? Are there any big design changes, crossbolted main caps, revised cam location or bearing journal sizes, bolt patterns, (following is speculation) I am guessing no distributor so there is probubly no place to put one, so what drives the oil pump? Revised oiling system, non-siamesed exhaust ports? I am curious, I haven't looked at any of the newer stuff in a while, wonder what changes the general made to the most popular engine ever.

NataSS Inc · #12 (**permalink**) 10-01-2003, 12:17 PM

the Ls6 uses a 6 bolt main cap. 4 from the top and 2 from the side. the rods are also a "cracked rod" design. Its the first time that I am aware of that that has been used on a motor. I may be wrong about that though. There are fewer head bolts on the LS1 than the SBC motors, why I dont know but I dont consider that a good thing. alot of the guys running turbo'd/blower motors that are reaching the 700RWHP mark are lifting the heads on a regular basis. The general concensus seems to be the lack of head bolts that is causing the problem.

the oil pump is driven off of the cam/timing chain. The bearings are also a camfered (sp) bearing. Your right there is no distributor. The LSX based motors also use 1 coil per cylinder for a total of 8 coils. Where the standard SBC uses only 1 coil. I do know that part of the ignition system is inside those coils which has made it VERY tough for any aftermarket company to improve on the GM design.

Mr.Fixit · #13 (**permalink**) 10-01-2003, 12:42 PM

Cracked rods are all the rage from what I have been reading. It's a whole lot cheaper to make a MiM conrod, score and snap the big end, and call it a day; than to forge, than machine, then balance. I read they moved the thrust bearing to the middle of the crank. Plastic intake, it's about time. I also read they won't tolerate much of a bore job, but why would anyone want to, who rebuilds motors anymore? Fewer head bolts, that makes very little sense. Oh well, I'll just stick with the original LS-6 in it's mk4 BBC form. That engine I do know.

Excaliber · #14 (**permalink**) 10-01-2003, 01:06 PM

Back in the day,,,,,,sodium filled valves were used to carry heat away from the valve head. One interesting use was in the Chev 6 292 motor. Not a "race" application, but for heavy duty truck use.

Ernie

Gatorac · #15 (**permalink**) 10-01-2003, 01:07 PM

Thanks for the info.

Good luck on your project.

avanti-176 · #16 (**permalink**) 10-01-2003, 01:09 PM

The motorcycle boys have been using cracked rods in their production bikes for some time now I believe. I really wish sometimes that our automotive engineers would pay attention to the guys putting together these bike motors, those guys don't mess around.

I do know that when Ford really wanted to hop up the Taurus without just adding cubic inches that they went to Yamaha. Not that the Ford guys couldn't do it but when it comes to making big power out of little motors the bike guys do some amazing things.

Have a good one,
Dan

NataSS Inc · #17 (**permalink**) 10-01-2003, 02:16 PM

Quote:

Originally posted by Mr.Fixit

. I also read they won't tolerate much of a bore job, but why would anyone want to, who rebuilds motors anymore?

That really depends on who you talk to. There are lots of guys running around on big bore LS1's that make some impressive numbers at the wheels. If you were going to bore one out you would want to use the LS6 block to do it. From what I have heard and read they are supposed to be a stronger block than the LS1 not to mention it also has a better PCV system on it.

People are saying you can take them out to 46x ci and still be fairly stable. But I personally wouldnt go that big. The 427 LS1/6 motors seem to hold together pretty well, make HUGE hp and very streetable.

Lightingrod · #18 (**permalink**) 06-26-2005, 02:25 PM

The new AFR heads for the LSx engines FLOW! They will put to shame a lot of after-market BBC heads!

cobrashoch · #19 (**permalink**) 06-26-2005, 03:06 PM

Mr. Fixit - Both you and I regretably need to take a second look at these guys for real. Things do change and they are the next generation hot rod standard engine by numbers alone, and that's not just a opinion. For example a complet 6/Liter LS6 motor comes in at a rip roarin' 380 lbs dripping wet, THINK COBRA> On the latest head the combustion chamber design is light years ahead of everyone else for running high compression, on standard unleaded gas too. And as NataSS Inc said the right factory ported head will support supercharged applications, no easy task for sure, in spite of the head bolts. (Studs anyone?)
The only thing I've heard bad about them is if they get hot from overheating they are toast, NADA. Everything warps. Not like a conventional built V8, you can't just let them cool down, then refire them up. I know, I know, I hate progress too. Esp. if they are right, and the horsepower numbers are unreal and backed up.
cobrashock/ old school

Don · #20 (**permalink**) 06-26-2005, 05:35 PM

Reference the Idaho Corvette Page on the LS 6

http://www.idavette.net/hib/02ls6/index.htm