dhdenney

iTrader: (53)

I was just reading through the forum as I usually do and the other day I checked out Lloyd Elliot's website and I was just wondering about my setup. I have had bad misfiring up top and I just replaced my opti and it revs like a champ all the way past 6000+. Previous dyno runs had yielded only 360 rwhp and I feel like it should have done more than that even with the miss. Granted, LT1 castings are restrictive but they were CNC ported maximum by Cornett Machine in Somerset, KY. Elliot uses LT1 castings, no? I also realize that a 9" Ford is gonna cost some ponies. I realize as well that dyno numbers are just numbers and track times are more important but I'm just getting curious as to how it's gonna do when I go back to the dyno. I plan on going to the track in the next 2 weeks too.

Brett95z

iTrader: (-1)

Im assuming you should have easily been more than 360whp. With a 396 though, you would most likely benefit from going to an aftermarket casting like an afr or something. Those 46 extra cubes suck more air than the stock heads can really supply, even if they are ported. I think you should be close to 400whp even with the 9".

dhdenney

iTrader: (53)

That's what I was thinking. I was hoping for like 410. Surely with the new opti I can hit that mark. I wouldn't think however that an LT1 casting would be costing me that much. If I built the motor today I would be doing some AFR 227's but I concocted this thing 3 years ago before I knew anything.

jimbob

iTrader: (4)

Even with a great tune those heads will never supply enough high rpm air flow to make big power up stairs (the reason cross section is too small). "360 SAE" isn't that bad with a 9inch and was the exhaust closed?

My old 396 combo lost 12 SAE rwhp over stock rear...(both had 3.73 gears) so, no gear blaming loss...

Almost every dyno guy on here uses either open/cut out exhaust or true duals to make big power.

At one time I use to think my engine didn't make any power...I was making 405 SAE with slp mid lengths, stock water pump, stock dual dual cat back exhaust and comp 305 cam. Last dyno before converting to auto was 393 (after 12 bolt install dyno). So, yes you are down on power, even after taking away 15-17 crwhp for 9inch. I would shoot for 400 with long tubes (closed exhaust though) and electric pump. If not, I would look at your DCR over SCR (your cam is way wrong for your scr), intake manifold restriction and look at the quench height as possible problem areas....

Oh, and one more thing...I used to have comp ported AFR 220's (actually 232 cc's measured)...anyway, they did not make any more power than a good set of ported LT4 castings. It's the whole COMBO that makes power not just the heads...at best with a good set of ported LT4's or ported AFR 210's you might see 10 to 20 crwhp over those CNC'd lt1's....our manifolds just suck for making big power

If you have any questions Pm me.....I have been through a hell of a lot of different heads and cam combos over the years so, I might be able to help if you get stumped....



Jimbob (old 396 owner..now coming 401 12.5 to 1 comp AFR headed monster)

dhdenney

iTrader: (53)

Well I was certainly shooting for 400-410 rwhp. I do have Hooker LT's through 3" Y-pipe and 4" Borla XR1. I would venture to call that the halfway between full exhaust a cutout. I also now have an electric WP so the only big power killer is the 9". I'm also working with a steel flywheel but I don't think that's killing much but I suppose the aluminum d/s negates the flywheel (more or less). It does make me feel better that that you think spending $2500+ on heads is worth 10-20 rwhp. I thought it might have been more like 50 but the more I think about it, if I had a solid roller with big duration, 50 might be more realistic. But I don't have a cam like that. Which leads me to another point. The cam. I called Combination Motorsports, gave them my specs, and I had that cam cut. So I've got a custom grind for my combo. It seems odd that you think this cam is way wrong for my static compression ratio. I believe I need some more info on that one.

95zpro

A bad opti or even wires for that matter can easily cost you significant hp loss. One cylinder can lose you up to 30hp if not more; there was a good tech article where one of the mags disconnected a plug wire to simulate a bad wire and it showed a before/after dyno run and the results were staggering...

jimbob

iTrader: (4)

With your SCR of 10.8 That cam should have been ground on a 108 or 110LSA with 104 or 106 ICL. That might (and I mean might) give you 10 hp. Also I'm a lift man .6 is what I shoot for so, if the extra DCR from a 104 or 106 ICL don't help much the added lift might...! You need a really low ABDC @.006 number to boost DCR for your cam like 68 to 70 degrees area..I like running 8.5 to 8.8 DCR in my combos...These are just starting points for good power...Give Brett Bauer (Lloyds cam guru) or Joe O a call and give spects, you won't be sorry!!!!!!!!!!

As far as the heads go, I'm assuming your CnC'd LT1 Heads don't have any power issues (tumble, reversion, slow port velocity or to high port velocity and they flow good). With that said, I only gained 10crwhp going from CnC'd lt1 heads from LPE (done by CnC heads out of Florida) to ported Lt4 GTP heads. I later swapped on the 220's and gained nothing over the old LT4's (scary..and expensive). Anyway, I'm throwing this out there just for your info..on what I'v seen between heads, you never know there could be more power for you between those....

The solid roller is an idea but I did not make much more over a good hyd roller (5 crwhp actually). You have to go BIGGG on a solid roller to make big power difference over hyd roller (in our engines). Good start would be an intake duration of 260 @ .05 with .650 lift.


Hope any of this info helps.....I just can't stand an under-achieving engine so, hopefully you can get this all figured out and do this

Jimbob

dhdenney

iTrader: (53)

Thanks for the info. I had the cam ground for street/strip nitrous use which is why they recommended 113 lsa. The reason for the lift is because of the limited gains on stock heads at high lift (heads weren't flowed but wouldn't have done much more between .550 to .600--I'm sure you know that). I've thought about having my CCs milled to 50cc. Raising CR the right direction? What should my SCR be for this cam?

SRZ

iTrader: (14)

It's all in the combo. I'm running LT1 heads on my 396, 11.1:1CR, 232/242 110LSA, lift .560/575 @ .050, FLP's through a GMMG and I'm @ 440rwhp. Stk water pump and stk rearend though. CF drives shaft w/ 3.73's and aluminum flywheel.

Vendetta

On my old LT1, I was only trapping ~110mph with a bad miss and opti issues.

dhdenney

iTrader: (53)

Sounds like I should be able to hit the 410 mark pretty easily. I'm just kinda nervous that I'm not making the power I should be. She runs good with the new opti though. I just waiting on that damn airbox and I'll be able to let her eat. I would think my cam is ok for my CR though. Ours are somewhat similar--mine is just a little longer on duration but your LSA is tighter. Compression only varies .3 and I'm running electric water pump. If I don't have an engine problem I'm thinking 430 should be pretty easy. Don't know why my cam wouldn't fit my combo.

jimbob

iTrader: (4)

dhdenney I'v already gave you a big clue as to the loss of power. By my calculations SRZ is close to 8.5-8.7 DCR. Yours is 8.05 to 8.12 that's ok if your looking for no power off N2O (Lloyd likes to set his combos at 8.3 for reference, which is near stock). I like the 8.5 to 8.8 rule, with good tuning (.04 to .05 maximum quench)... 9 to 1 works if your in a cool area with great tuning and .04 quench! Your leaving some on the table, Dyno again and see what you have..."SAE" with your exhaust and 9 inch, it should be in the 400 area if running good It's all in the Combo ...Less then that and your looking at heads/manifold cam and such as an issue....

Jimbob

dhdenney

iTrader: (53)

Well my cam has the usual +4 built in. Has that been factored? Can you point me to get a good online calculator for this stuff? Do I need more compression for my cam or more cam for my compression?

jimbob

iTrader: (4)

Do a search for DCR calculator by Blair Legate or Pat Kelley.....Do not use one that's uses .050 duration numbers...only ones using base duration and ABDC at .006 lift...Here are good discussions about DCR...

http://web.camaross.com/forums/showthread.php?t=379859
http://web.camaross.com/forums/showthread.php?t=382484

Jimbob

dhdenney

iTrader: (53)

Called Combination MS and they said they would have me a cam card sent out soon. I wanna get all my specs again so I can play with those calculators. I think ultimately the wider LSA is dropping my DCR, but it was cut for the nitrous use. They maintained that this was a decent cam for the setup as a whole.

jimbob

iTrader: (4)

Maybe these...
.006 .050 .200
Intake 288 236 157 .555 lift w 1.6 rocker
Exhaust 293 242 164 .576 lift w 1.6 rocker

113 LSA 109 ICL

Jimbob

dhdenney

iTrader: (53)

Hey thanks!