Carbureted LSX forum - HP guestimates of new combo

Im building a new motor for the season and wanted to see what the LS pros think.


NEW COMBO:

365ci (.005over) iron block
LS3 heads
12.5 to 1 compression
K1 rods
Victor JR single plane
Full length headers 1 3/4-1 7/8 stepped headers
cam specs in progress
Holley 1000HP carb
MSD-6010 ignition

Not sure without cam specs, but that combination should produce 475 give or take on a dyno to the back tires, depends on the dyno and the rest of the drive line.

what tranny

Not sure without cam specs, but that combination should produce 475 give or take on a dyno to the back tires, depends on the dyno and the rest of the drive line.

If that motor @ 12:1 carbed with any respectable camshaft put down only 475 id set it on fire and roll it off a cliff.

Assuming he is using a automatic with a large converter, the dyno readings are not what you would think, you cannot go by dyno numbers asides from tuning purposes.

The track is where you can find the power output. A friend with a LS3 with cam and the works made 460 through a stalled auto, and every dyno will read different, so hence the reason i say "give or take".

Trans is a T400 but may be switching to a T350 this year, I was hoping for 500 to the wheels on a dynojet. The last combo was a junkyard LQ4 with untouched 243's, mild cam, headers with a Wegner single plane and made 400hp to the wheels with a badly slipping converter, T400 and 4.10 gears with Hoosier Quick Time Pro's D.O.T(slicks with grooves) on a Dyno Jet. I replace the converter with a 4000stall unit and the car picked up half a second in the 1/4 along with 1.56 60ft. Anyway back to my new combo...I Havent milled the heads yet but i am thinking about it. Ive got a custom cam coming from on of the sponsors(not sure if its ok to say who it is though). I do not have cam specs as of yet but it will be taylored to the combo.

I use the chassis dyno for tuning purposes and finalize my tune at the track for different weather conditions. Ran a best of 11.53 last year with the junkyard combo in a 4000lb car and was very surprized it ran like it did. Probably going to an electric w/p this year to freeup some extra HP too.

Pump or race gas?

i would say 500 to the tire would be a good guess also.

I don't know about RWHP, but I would say near 600HP at the crank with the appropriate cam.

475-500 you should do some port work on that victor jr to flow a bit more

The 10" 4000 stall converter will probably not be able to be used. Im waiting on cam specs for that but it will probably be 5000+ and the combo will be on race gas for a while then E-85 or Methanol. Im gonna have the Jr flowed on a bench.

Yea, i wouldnt expect the numbers ona dyno to look as pretty as they could be with a manual trans, so anywhere from 450 to 500 is possible, depends on the dyno ect.

I don't know about RWHP, but I would say near 600HP at the crank with the appropriate cam.

agreed^^^^^^

I don't know about RWHP, but I would say near 600HP at the crank with the appropriate cam.

620ish is the goal, 600 is close enough for me. Cam will be in the mid 230's I /240's E

Decided to go more agressive on the cam selection. Compression will be bumped to 12.5 from 12 to 1. Its going to be around 250* @ .050 on a 110 or 112 LSA. Leaning towards the 112, I had great results with my Catherdal port LQ4 pump gas motor last season using a 112 LSA in my heavy Coupe Deville. I think average across the board HP and TQ numbers are more important in my combo than peak numbers. I need to get from point A to point B as quick as possibe.

That is one serious camshaft.

I have yet to pull the trigger on the cam but i plan to spin it to 7500, the heads have enough air to go 8000+ but i dont want to spin it that high, ide like the motor to live for a while. I'll be using race gas but i plan on experimenting with E85/98. Ive been talking to a couple different cam guys but undecided at the moment. Its still a cast crank and im sticking with the stock rockers. The converter will be a 4700-5000 8". Will more than likely be an 8* split. Any input is welcome......

I have yet to pull the trigger on the cam but i plan to spin it to 7500, the heads have enough air to go 8000+ but i dont want to spin it than high, ide like the motor to live for a while. Ive been talking to a couple different cam guys but undecided at the moment. Its still a cast crank and im sticking with the stock rockers. The converter will be a 4700-5000 8". Will more than likely be an 8* split. Any input is welcome......

Sounds like a rocket ship in the making. I know you are going to post a video when it is done so we can hear that sweet LS music!

Oh yes I will def post pics and video's!

going for broke

what pistons are u using for a 12.5.1 cr? i looked into the +12cc dome Wiseco pistons for my build but i guess they only accept cathedral style head due to valve size. otherwise i would love to use some square port heads like you are doing.

Im using the Wiseco 12cc piston, they said they can be used for up to a 2.20 intake valve. We shall see.

The Wiseco 12cc piston works with the rectangular port heads with a 2.16 intake valve, I just test fit and clay checked one, plenty of room.

Shifting at 7500? what oil pan are you using? I've a few parts to increase my shift rpm up there too, but I am told I need to increase my oil pan volume to 6 litres, or risk pumping it dry durring a run.

Sounds like stout build
:corn:

Im using a V8 H3 oil pan with a stock LQ4 oil pump I ported and shimmed. The oil to the rockers will be restricted using custom pushrods w/ a .040 orifice to help keep more oil in the pan.

The Wiseco 12cc piston works with the rectangular port heads with a 2.16 intake valve, I just test fit and clay checked one, plenty of room.

thanks for letting me know. i was just told by a sponsor that any cathedral style LSx head would work. but now i know square ports will work to!!!!

Bumping the compression up to 13.3 to 1, Cam is ordered and i should have everything back from the machine shop by next week and have the cam. Hoping for 600+ at the crank

Good luck man. It's cool to see someone using LS3 heads on a pretty serious engine. I think your combo is gonna help prove that LS3 heads actually can work good.

By the time this project is done.............................im betting on 15.5 to 1 compression with a stock eliminator spec cam, lol. AWSOME build. Cant wait to see it done. Eric L

Thanks, It was supposed to be a budjet build...lol...but got outa of hand. Its still kinda budget with the exception of good pistons and rods. Block was a well seasoned 400,000 miler and just having the crank polished and balancing the rotating assembly. Cam will be in the 240's on a 110 LSA. This is my first experience with the LS3/L92 stuff so we'll see what happens. Im worried that the surface finish on the milled heads and block will be too rough for the MLS gaskets so im gonna try a medium block sander with 400 grit paper.

Did you get your stuff back from the machine shop?

Ya def. in the high 400 if not low 500 with a tune maybe! idk

BUMP. Waiting on updates.

Its been a long 2 months since my last update in the carb section but it got the motor finished lastnight. Lots of 4am nights within the last week or so. I'll post pics of it tonight before it goes in the car. I think i will need another lower rad hose for the electric w/p but other than that i'm hoping for another couple hrs or so of work.

Compression was finalized at 13.28 to 1, everything went together nicely. I had no clearencing issues with the Cloyes double roller hex-adjust timing set or the WISECO's with the reluctor wheel.

Shooting for 500rwhp on the dyno

More to come.......

I forgot to take pics before the motor was in but it lives! Fired right up, good oil psi and sounds badass through the mufflers idling. I hope it runs as good as it sounds. You can def notice the compression crackle in it. Cranking compression was 225psi w/ a gear reduction starter before i fired it. Rings still need to breakin then I'll recheck it.

I will try and post a pic later tonight

sick i bet you had a smile ear to ear. what valvetrain did u end up going with? can you post any videos?

You gonna break it in on jackstands or drive around?

You gonna break it in on jackstands or drive around?

Prob drive it and run it in the driveway. Lets see how my 4700 stall converter likes street driving.....lol

sick i bet you had a smile ear to ear. what valvetrain did u end up going with? can you post any videos?

Ya I did! It was 3am when I fired it up...lol

Stock GM valvetrain for now, Comp pushrods and Patriot ".660" Gold kit with titanium retainers

I'll try and shoot some video and put it up tomorrow.

Ive got some pics from my phone and an idle clip now i just need to transfer them to the computer. I'll prob put up a link to youtube for the video.

Couple pics, fuel line and the steam bypass are temporary.

299719

299720

It's not the best video. Its from my cellphone.

http://www.youtube.com/watch?v=LTyOuIEHIs4

sick. sounds good. have you taken it for a spin yet?

Just puttered around the block. Picked up fuel today, i didnt wanna run out. The sound in the video does no justice......

If the weather holds out i'll be taking the Coupe to the chassis dyno friday evening after work. I'm not sure if I should post results here or in the Dyno section.....

Looks awesome and sounds great.

If the weather holds out i'll be taking the Coupe to the chassis dyno friday evening after work. I'm not sure if I should post results here or in the Dyno section.....

u can put it in both? or just post a link to the dyno forum.
im sure the camera does no justice. its hard to get a good vid unless u use a good actual video camera. im sure it sounds sick though.

I actually drove the car to work...lol...to see how it ran on the street. Runs fantastic, coolant temp stayed below 180* with the Meziere electric race pump and its in the mid 90's here in Ohio today. The 8' 4700 stall doenst feel all that high unless i really snap the throttle hard. I really didn't think it would be very happy on the street with the big cam and high compression but its quite content.

I'm still on schedule to take the car to the chassis dyno Friday, hoping for some good results.

Sounds awesome! I am in the middle of a very similar build but with PRC 237 Cathedral port heads and around 12.85:1 compression. Cannot wait to see your numbers! Also, what mufflers do you have on that car?

Luke, I'm running Dynatech mufflers. They are a bit much on the street but it only gets driven to some car shows. Its mostly a drag car.


Ive still got the timing curve in it from the last motor, total timing was at 28 or 29*, I think this motor will want more timing.

I may also have to put more converter in it, the one in the car was designed for a big block on spray in a lighter car. It feels a bit too tight when the throttle is snapped.

Sweet motor...:nod:

Sweet motor...:nod:

Thanks man. I kinda wish i had 75 more cubes though...lol

Dyno time tonight!!!!!!!!! I'm not sure how the converter is going to affect the numbers but at least i can tune the jetting and timing curve. I had 28 total and all in by 3000rmp and it seemed sluggish but im sure some of it is the tight converter in it. Doesnt seem to even flash to 4000. It flashed at 5000 with a BBC on spray. Calling ATI soon to order the 5500 they speced for it.

Anyway, i changed the timing curve to 35* total all in by 2000rpm and the car is much more responsive and pulls harder so we'll see tonight.

so.....?

ttt


???? well ????

OH MY GOD, OH MY GOD, IM DYING HERE! LOL. Please, we need some freekin numbers...............................Jesus, lol. Your killing me dude....................killing me. Hope all went well. Eric L

Sorry for the delay guys, busy weekend. Well it made the best power @ 37* total timing, all in @ 3000rpm. The converter is way tight and flashed @ 4800rpm.

Motor:
Gen 3 6.0 .005 over
stock 397,000 mile crank
untouched LS3 heads
untouched Edelbrock Victor jr intake
1" open spacer
1000HP carb
Wiseco 13.28 to 1 comp
K1 rods
248/256 cam on a 110lsa
factory lifters

Drivetrain consists of:

8" converter
28x10 slicks
T400 trans
Double Cardan factory driveshaft(weighs a ton!)
8.5 rear end

The air was shitty and it was raining, Dynojet dyno. Ok so for the results....

It made 481hp @ 7100(was still climbing but it hit the rev limiter @ 7200)
It made 387ft lbs @ 5600(kinda disapointed)

Dyno operator said my drivetrain losses were about 23%

That being said if i did my math correct comes out to 620hp and 500ft lbs @ the crankshaft.

I'll post more on the combo later with a dyno sheet and also post it in the dyno results forum.

I'm probably going to experiment with a smaller camshaft, this one @ .050 is 248/256 on a 110 lsa and .610 lift

Total investment with parts and machine work(I assembled the motor)is $3500, I had the starter, headers, carb, pan, and ign system from the previous motor. So for a low budget build its not too bad.

Good job on the results. Amazing. Congrats. Eric L

Nice numbers. Do you think it'll make a little more HP when everything breaks in a little? Why did ya'll limit it to 7200? Not trying to give you a hard time, I'm just curious is all.

Nice numbers. Do you think it'll make a little more HP when everything breaks in a little? Why did ya'll limit it to 7200? Not trying to give you a hard time, I'm just curious is all.

The motor only has about 30 miles on it if that, it may make more power once everything is settled. I limited it to 7200 just to be safe and it has stock lifters.

I need to dump the big heavy driveshaft and T400. Prob woulda made a bit more power with radials on it too but i didn't have time to switch them.

Here is the dyno sheet, off to the track tomorrow.

Here is the dyno sheet, off to the track tomorrow.


Any updates?

nice build

Looking around on racing junk and it looks like he is selling the caddy.


http://www.racingjunk.com/category/0/unset/post/2259394/HOT-ROD-77-CADILLAC-COUPE-DEVILLE-LS1-LS3.html
http://www.racingjunk.com/category/24/Other/post/2249402/77-Cadillac-Coupe-Deville.html

Oh no, I hope everyting is alright with him and his family. Best of luck brother. Eric L

What ever happened to this guy? I sure hope everything is alright. I was watching his project for the longest time last year, and than..............poof, he dissapeared from the face of the earth. He hasnt been on here since november, wow. Eric L

Still no word? This cant be good.