Ok guys I just got my engine back from the builder and I am worried that it has too big of a cam for my purpose. The engine is a 500" 440 with 10.5-1 compression. It will go in my 71 challenger convertible. It has source cnc heads and a 6 pak. I am using TTI header. The car has power steering, ac and power brakes. I am using a MSD all in one distributor. Im looking for a 100% street car that is fun to drive.

the cam installed is 110 lobe separation 258 @ .050 on the intake and 266 @ .050 on the exhaust with .571 lift on both. It it is a hydraulic roller.

I know strokers need more cam but am I still going to get a decent enough idle? I saw the cam card and I am worried that it seems like a lot of duration.

PS it was run on the Dyno and it made 575hp.

Thanks
Sanman68

I have a very similar combo with Source CNC heads and a Comp cam that's very similar. It's a solid roller with .575 lift and 262 duration, and 110 lobe separation. It drives beautifully on the street and has run 11.55 through the mufflers on sticky street tires. I do not have any power options, so vacuum isn't a big concern for me. Not sure how the vacuum operated items would like it, but it's a monster on the street. Good luck. What gears are you running, and do you have a loose converter? I am running 4.30's with a 3800 RPM converter. Tom

I plan on using 3.23 gear, it is a automatic with 3000 stall. Tom what vacuum do you have at idle?

Sanman

You need to expand on specifically what this means to you. The opinions on what constitutes a decent idle varies tremendously.

Yeah I'd say that cam is too big for a cruiser type car. The Comp 286HR is probably a better choice. It is 236/242 duration. The next size up is the 292HR which is 242/248 and is listed as having a rough idle. I've run the 292HR on the dyno in a higher compression stroker and it runs nice, but the idle would probably be fairly rough.

With 3.23 gears and lower stall point I'd go smaller on the cam. The other thing is that unless you are highly skilled at carb work the big cam won't be much fun with the six pack. Those carbs are not designed to work with a big cam.

For what I like in idle and low speed characteristics, the 286 would be my choice. It would probably feel similar to what I have in mine now

Nothing else to add here......

The 258/266 hyd roller seems way too big for the application IMO.

...easier to change it now than after you find that you don't like its manners...or lack there of. That is a big cam for 3.23 and 3000 stall.

I have a 512 in my 68 Charger street car , AC 3.54 gears, OD trans , my solid FT cam is 248 @ .050 110 LSA, take about 6 deg out for the lash, it works very well for a street sometimes strip car, any more overlap & it would not be very streetable for my combination.

Thanks guys. Like what was said it will be much better and easier to change it now before I get it in the car and don't like how it works.

I told the builder it is a street car and I need a decent idle. I am kinda pissed off at him. I asked for the cam specs and I should have insisted. Oh well live and learn.

I agree if you insist on the 3.23 and that converter then I would use a different cam. It would work ok with more gear and converter as I run a solid flat tappet that is 264 & 270 @ .050 with .585 and .592 lift on a 110 LSA. Plus I use 1.6 Hughes rockers but I wanted a nice slightly choppy idle and wanted to make some power so I run 4.30's with a 30" tire and a 4200 flash 9.5 converter. And my car actually idles a bit smoother then I thought but I love it. You can here my idle a little in this clip. But with 3.23's and only 3000 stall have a good cam person spec you a nice cam for your combo. Dwayne Porter (Fast68Plymouth) speced my cam and he did a great job as it works and runs just how I wanted for my street car. Ron

https://www.youtube.com/watch?v=bYIM2HLaOI4

Thanks for the video. Idle seemed pretty good.

Sanman68

I have a 505" with a 231/239 @ 0.050 Voodoo cam. I'm like you...I wanted a 'nice' idle (which is very subjective.)
I just got it running for the first time today. I have a lot of tuning to do before it is as good as it could be.
But for now it's got 13" at idle, with only 10d of advance at idle.

As already mentioned, the definition of "decent idle" varies a lot. If you want to be able to idle at 600 rpm while balancing a quarter on your air cleaner, that cam isn't going to do it. My 451 has 272@.050 solid and it idles "decently" at 1100 rpm. Some people are running even more cam than that on the street...

Anyhow as you say, it's better to have this in-depth conversation with your builder before the project is complete...