New motor not performing well

[devildog1]

ok... The issue is, new motor getting Dyno tuned and numbers are not good. I am ok at the moment with HP and TQ for engine stop producing at 5800 Rpm. That is what I cant figure out and I have a few ideas, but want to here some of yours. Here is the build: Forged 396, dart pro1 180 cc heads LE ported and larger valves added, cam is LE 240/248 579 with 110LSA, Intake is Victor EFI single plane, Nitrous outlet elbow, Monblade TB, 24X setup, Headers with 3 inch exhaust. Let me know your thoughts on what would be holding it back.

[popo8]

Do u have a dyno graph for us....

A/f , etc.

[devildog1]

Not yet. This evening he is going to send it to me. One thing the machine shop mentioned to me a few minutes ago when I talked to him was the springs I had, came with motor, seemed kind of lite. He suggested changing but I thought they should be fine, I think I could be wrong. It would cause this he said.

[popo8]

NightTrain66

[devildog1]

Already talked with Lloyd about all this. Could be intake as well and plan on having him port it out better

[Fastbird]

Heads. Even fully ported those heads are only going to CC out on the intake side at probably 200-205CC. That's choking that motor down especially with a cam that size that's going to want to breathe up top.

Case in point. Buddy of mine had a similar situation. 383, AFR 180's ported by TPIS, 244/254 cam, Single Plane, D1SC blower. Made low 614 RWHP. Changed, and ONLY changed, to a set of AFR227's, and picked up 86 RWHP, got to 700 on the nose. I screamed and hollered at him for a few years that his heads were holding him back.

[NightTrain66]

crummy part about the Darts is that even fully ported they are small at the pushrod pinch and will reach sonic choke sooner than a ported set of Trick Flows or AFR'.

These should still feed a 396 past 5800 RPM before choking and it should peak around 6100 RPM as long as nothing else is restricting flow (intake portwork, TB, CAI, headers, exhaust, etc).

I have spoke with him thru email and I am waiting for more info back but spring pressure, rocker adjustment, what lifters he is using, etc are all things to check.

Lloyd

[Fastbird]

NightTrain66 just curious but how big did the runners on these get after porting? I know that's not everything, but just a specification I'm wondering about.

[devildog1]

Car not hear. Need to check those things Lloyd mentioned email. What I do know is that spring pressure was mentioned by the machine shop when he went over the motor and if I remember right it was like 110 or 120 at seat and 345 open which is way to lite and is where I am going to start checking when I get it home.

[devildog1]

http://images.tapatalk-cdn.com/15/05/15/37b48cf13deef42bec22039701024212.jpg

Here is the dyno. Looks worse than I thought.

[blackbirdws6]

I'm going to guess springs here without any other info. What lifters are you running?

[NightTrain66]

man, I am not sure when these were doen, who they were done for, etc. He mentioned he bought the car or engine with the heads on them and that is all the info I have.

IF I did thema nd did 2.08 valves they would have to be in the 205-210 cc range.

Throat diameter would be large enough, shortside would be large enough, pushrod pinch is the restriction on these heads.

Are there are stampings on the end of the heads with customers name, date, etc?

IF there is 110-130 lbs on the seat, that is a big problem to correct.

I would set them up at 155-165 lbs on seat and 400 lbs open if cast cam or you can go higher than 420 lbs open pressure if using billet cam.

Lloyd

[popo8]

Almost 400 rwhp... that does not sound bad to me. 1hp per cube at the rear wheels is nothing to laugh at... what were u expecting the numbers to be?

[devildog1]

Yes. When I bought them we talked about name and date. Sing 08.

[devildog1]

Well, it is only 18 hp more than my stock bottom, ported stock head and intake cam motor that I took out. Was expecting more than this...lol. 425 to 450. I also have a 300 shot of nitrous on it that is not quite hooked up yet and I want to get the rest right first.

[devildog1]

http://images.tapatalk-cdn.com/15/05/16/58e89f421cf0f0367006a9c293dba664.jpg

Here is a pic of the motor. I will also need to do away with this cold air setup. Any suggestion would be appreciated

[miller09]

I agree i would think it would make closer to 450whp

[popo8]

Ok... i was always under the impression that 1hp per ci at the flywheels was good... with the exception of solid roller high cr builds.

[devildog1]

Has any bought or seen on a camaro those 3" high ss hoods? If so do they give more room toward the front of hood at all?