Generation IV Internal Engine - 387 all bore, LS7 top end

Thinking about building a 387. Stock LS2 crank, 4.125 dry sleeve LS2 case with ported LS7 heads. Haven't seen this combo before with those heads. Oil consumption shouldn't be a worry. Any guesses as to how high in the rpm range it would make power with a streetable hydraulic cam and would stock rods with ARP's be up to the task?

I think you'd be fine with the stock rods as long as you have the upgraded bolts. I wouldn't know where it would peak or make power to unless you give us your cam specs and let us know what intake you're going to use.

That combo will spin as high as you can keep you valvetrain stable.Even running stock port LS7 heads it should make killer topend power.

I would replace rods if you spin it over 7000rpm which that motor will be capable of. As long as you keep it NA it should be fine.

Nate

why would you spend that kind of money on the sleeves, top end, etc., and want to use stock rods. i considered these dimensions for my setup, 11.6:1 solid roller. with the cam and my heads, it would make peak power around 7800 and would rev to 8500-8800, and i have a moderately lite weight setup.

why would you spend that kind of money on the sleeves, top end, etc., and want to use stock rods.
Got no problem buying aftermarket rods. But I don't blow money on stuff I don't need. But if they aren't up to the task of course I won't use them. That's why I'm asking :)

I think you'd be fine with the stock rods as long as you have the upgraded bolts. I wouldn't know where it would peak or make power to unless you give us your cam specs and let us know what intake you're going to use.
It would be the LS7 intake. Cam, I don't know. Nothing too radical.

if your trying to keep the cost down a motor like your talking about probably is not the way to go. it will make its best power way up top and you will have to spend a lot of money to keep it together that high.

if your trying to keep the cost down a motor like your talking about probably is not the way to go. it will make its best power way up top and you will have to spend a lot of money to keep it together that high.
I've seen other all bore motors, and they don't make just good top end power. They will still blow the tires off the line. But I have no use for 450rwtq at 3500rpm in this car like my other engine puts out in my other car. I'm not expecting to be able to build one super cheap. But I don't want to spend way over 10 grand, either. And I don't want to buy stuff unless it's needed. Been there, done that.

Is the wet sump up to the task of 8000~ rpms? (I'm seriously wondering :) )

Is the wet sump up to the task of 8000~ rpms? (I'm seriously wondering :) )
Good question.

:corn: I have been seriously thinking about doing the same thing. Subscribing!

Is the wet sump up to the task of 8000~ rpms? (I'm seriously wondering :) )


of course it is.

also manley rods are the way to go imo. there is a machine/engine shop in ft worth(does lots of nascar/pro stock work) that did a test on them. spun the engine to 11000 rpm, disassembled it, wiped the blue color off them, weighed and measured them and they were perfect. if you want more info, just pm me

The T56 rebuilds car is wet sump and spins 8800+ rpms. They are changing over to a dry sump system shortly though.

I have had good luck with my Melling oil pump and Moroso oil pan windage tray and pickup. I am switching to dry sump on my new build because I am going to turn the next beast to 9000rpms. The 402 liked to be turned lots of rpms. I have had very good luck with my Beck manifold, but I do know that Patterson racing uses a lot of the Wilson stuff. I would like to see a A to B comparo between a Wilson manifold and a Beck manifold.

of course it is.

also manley rods are the way to go imo. there is a machine/engine shop in ft worth(does lots of nascar/pro stock work) that did a test on them. spun the engine to 11000 rpm, disassembled it, wiped the blue color off them, weighed and measured them and they were perfect. if you want more info, just pm me
The I beams or H beams?

of course it is.

also manley rods are the way to go imo. there is a machine/engine shop in ft worth(does lots of nascar/pro stock work) that did a test on them. spun the engine to 11000 rpm, disassembled it, wiped the blue color off them, weighed and measured them and they were perfect. if you want more info, just pm me
The I beams I assume?

Actually this is really close to the motor that showed up in the 2004 Pontiac GTO Ram Air 6
http://www.seriouswheels.com/cars/top-2004-Pontiac-GTO-Ram-Air-6.htm

GM's team used a LS7 block (4.25 bore) along with a 3.62" crank to make a LS7 389.

What I'm unsure of is if the 575hp rating was crank or rear wheel (probably crank hp)...

I've been thinking about a similar motor for my gto as 389 was the GTO's 6.5L moniker.

Actually I've thought about making a 389 from a L92 block and using a 3.75" crank (would call for custom crank, and pistons though).

Good luck with your 387 it should be a nice powerplant.

of course it is.

also manley rods are the way to go imo. there is a machine/engine shop in ft worth(does lots of nascar/pro stock work) that did a test on them. spun the engine to 11000 rpm, disassembled it, wiped the blue color off them, weighed and measured them and they were perfect. if you want more info, just pm me
The wet sump can handle 8K, but it better be set up perfectly.

Actually this is really close to the motor that showed up in the 2004 Pontiac GTO Ram Air 6
http://www.seriouswheels.com/cars/top-2004-Pontiac-GTO-Ram-Air-6.htm

GM's team used a LS7 block (4.25 bore) along with a 3.62" crank to make a LS7 389.

What I'm unsure of is if the 575hp rating was crank or rear wheel (probably crank hp)...

That's pretty nice. I'm sure it's crank hp, but even so that's not bad at all.

I was reading another thread and noticed this guy actually has one.

http://www.ls1tech.com/forums/member.php?u=3297

I was reading another thread and noticed this guy actually has one.

http://www.ls1tech.com/forums/member.php?u=3297
I've seen a couple before. But I've never seen one with LS7 heads. I bet it would pull like a mofo.