[stobin]

After speaking with Dave at SD, I am considering the OF cam for my 466 EFI motor. I currently am running a Comp Hyd. roller with a .360 lobe with 1.65's, 242/248. The current set up is very powerful, but the idle and overlap is tricky to tune. I like the OF cam since many people have had great results with it. The difference will be in the 114 LS vs the usual 112 LC. My question is does anyone have the OF cam on a 114 LC, and what are your impressions. The combo I have consist's of multipoint EFI, 466 CI, 10.3:1, 310 SD E-heads with ported Torker 2 EFI. Car is a 5-speed and 3.73's. Current dyno results, 437 rwhp, 457 rwtq. Thanks.

[Cliff R]

At 10.3 to 1 static compression ratio the Old Faithful cam would be a good choice on a 114LSA.

In my engine at 11 to 1 compression it's very mild on a 112LSA. In lower compression engines it starts idling a tad "rough" below about 900rpm's. Moving it out on a 114LSA will improve things some at idle speed......Cliff

[krisr]

Stobin, what problems are you having to dial in the idle? I've spent a fair amount of time experimenting with different tunes to set-up my 400 with an XR288HR cam at idle have finally just got it to the point where i'm very happy with how it idles - needs 1000rpm to idle and doesn't have much RPM jitter so the motor is happy turning there and still retains some cammy/lopey sound.

It ended up with setting timing at 36° around idle with minimal extra cold start advance and run the AFR's around 13.2-13.5 (hot) @ 1000rpm. When cold it needs around 12.5 AFR on the wideband to run right then taper off as CLT rises.

What engine management are you running again? If you want a second set of eyes to run over the tune yell out but will also need datalogs.

[stobin]

Krisr: Good to hear from you. No real problems with the idle. I have the idle speed set at 1100, but even there it has a noticeable lope. It runs good though. The timing is set at 26 degrees. AFR at idle is 15.1. The real reason for the swap is to get rid of the 110 LC. I know it will run better, and honestly, the choppy idle is getting old. I run the Retrotek Speed ECU. I can send you a data log, not a problem.

Cliff, thanks for the advice. I always keep the idle speed up around 1100 so it should keep it a little smoother.

[Cliff R]

With 11 to 1 compression my engine is fine with 10 degrees initial timing. It idles at 750 rpm's, barely moves when placed in gear and 13.5" vacuum.

Idle quality is very good, just a hint that there's something going on in there, but it is as smooth as a 69 400 engine with an 068 cam in it.

I can make it idle with more "attitude" by leaning up the idle just a tad.

It doesn't want or care for more timing at idle, I've tried adding between 10 and 15 additional degrees and it just introduces a "skip" into the engine that I don't care for.

Compression can be your friend when it comes to these things. I built and tuned a near identical engine closer to 10 to 1 compression, and it idles much rougher than my engine does, with 2" less vacuum at the same rpm's.

We tuned another 455 at 10 to 1 compression with a 230/236/114 HR cam in it, and it was dead smooth clear down to 600rpm's in and out of gear.

That engine also cranked out 502hp/599tq on the dyno, and had a big-flat torque curve clear across the loaded rpm range. So far, nothing but positive results using 112-114LSA cams in these engines with the KRE heads......Cliff

[HWYSTR455]

LSA is a funny thing, like, as you add duration, and you add LSA, it's a wash. Displacement too. So, a 400 with 110 at 230 degrees will be the same as a 455 with 114 at 245 degrees, kind of. Also keep in mind that newer performance cars are coming with like 116, 118, and even 120 LSAs, and those are smaller displacements than what we normally run.

With that said, as you add LSA, don't shy away from going bigger on the duration too. The OF is 236/245, and with a 114, you can easily go another 10 degrees duration without effecting idle quality. I run a solid 246/252 solid roller on a 114 in a 461, and the idle quality is really tame, like, I would have prefered to go even bigger. (more duration).

Here's the cam card for general reference (attached pic).

Also, some feel adding LSA is for sissies, but it is a great tuning parameter in reality.

.

[PONTIAC DUDE]

I think more of your problem is the cam profile itself rather then the 110. With trying to allow the A/F ratio and computer to read. The fat cam and/or overlap could be messing with ya.

Valve opening and closing rates play a big deal with Computers and EFI too.

[stobin]

P-Dude hit it exactly. The overlap based on the LC with my duration is what makes it tougher to tune. That is why I am looking for a larger LC cam. Yes the OF cam is smaller, and I have considered that as well. I am looking for a cam that will still keep the powerband and torque at a level I have or greater, but with a tamer idle. But with that said, I do not want it to sound stone stock either. Driveability is the key here. The car is very driveable now, but the overlap is just too excessive to really make the EFI work as well as it really could. I am open to any suggestions on cam profiles in the 114LC range.