25 years ago I didn't get a chance to try it, so now I am

The cam is actually the old Mini-Express .654/278@.050, .024/.028 lash that I bought used and had Schneider Cams reground to restore the lobe taper (and also reface the mushroom lifters). It is now .652/272@.050, .016 lash.

Anyhow I know it won't make a lot of power below 3000, but from there to 7000, anyone who's run one has been very happy with it (and as originally advertised by Direct Connection, "comes very close to roller cam performance at about half the cost"). Back when the Big Roller was .750, 286.

Haven't checked the cranking compression, it is what it is... may measure someday once I get the rings broken in under load.

Right now I am having trouble choosing between:
1) locked timing at 34, current primary blade holes, or
2) 24 initial, 34 total, holes in all four blades as needed to idle.

Which would you do? Limited street, even more limited strip.
thanks.

I don't recall what your cr is, but I dont know if I believe the bottom of the good part of the power curve will start at 3000rpm.
Over 4000 more likely, especially if the cr is on the low side for that much duration.

As for the timing, I'd lock it out..... Get it all warmed up..... And see how high it can be before fighting the starter.
Then I'd modify the distributor so I could start at whatever point that is, and end up at wherever I wanted the total advance to be.
My guess is I'd end up with initial at 30-ish, 36-38 total. Since it's a stick I'd use the lightest springs and the advance would pretty much just be there as a starting aid.
If I thought I really needed vacuum advance, I'd have it limited way down to about 5deg, and require a fair amount if vacuum to operate, so the only time it would function would be at part throttle cruise.
I wouldn't be using a pcv valve.

I don't know what your carb is, but it really should be something with 4-corner idle, and I'd likely end up with holes in all blades.

After it's got a few hundred miles on it, you may want to pull the carb and look down the intake ports with a bore scope/camera.
It might make you question that cam decision.

Dyno sheet:
10:1 446, rpm intake, 22deg @.050 less than your cam.

OK, that's another vote for locked timing

I'm using a Jacobs "Boost-Master" (aka "Turbo-Timer") retard unit and rev limiter. It has two 0-15 degree retard knobs, originally intended to switch from one to the other with a pressure switch. In my application the second retard will be for nitrous and will be activated by throttle microswitch.

So I can dial out 15 degrees of timing at start; just have to remember to twirl the knob when hot. It starts fine when cold at 34.

Re: vac advance, with my 10.3:1 CR (iron heads, quench) I figure it will tolerate some advance at cruise. Idle vac is only 6-7" so definitely won't be activating the can at idle.

Carb is an old 2-corner 800 DP. I'm having discussions with Dom (Thumper) and he's going to make me a better carb. In the meantime I might as well play with this one. BTW he also favors locked timing with this cam and CR.

You and BradH are both recommending that I not run the PCV valve. Can you please tell me why? thanks.

I prefer not to contaminate my intake charge with oil vapors, or have oil residue building up in the intake runners or the backs of my intake valves.

IMO, the negatives outweigh the positives.
If you feel you "must" run one, I'd plumb an oil separator/catch can into the line.

The cranking compression test is more about getting more info to have a better idea about how much trouble it'll be getting any drivability issues sorted out.
The lower the cranking pressure, the harder it will be to make happy.

Thanks for the info. That dyno sheet is interesting... what does it look like below 3900? Did you start your pull at 3k or less?

There's still 492 ft-lb at the bottom of your sheet, that will move my A-body on the street without going to 7K on every shift

What do you mean about using a borescope? I assume there'll be soot from reversion?

This project really won't see much use, just a little "Saturday night special" driving and maybe an occasional trip to the strip. I figure the bottom end will be soft but the higher I spin it, the more power it'll make. At least someday when I get better heads. Besides, I can always change cams if I have to.

The pulls were started at 3500(498.2ft/lbs)so no idea what it would be like at 3000.
I wasnt the one actually running this particular motor....... I probably would have started at 3000 if I had been running it myself.
On these mild street motors I like to see the point where the bottom starts to really fall off, and it's obviously lower than 3500 on this one.

It takes way more than a big cam to make power to 7k on a bb mopar.
If the heads, intake, carb, headers won't support it, then it just noses over wherever the smallest "cork" starts to come into play.
Then you can have a situation when the cam is too big to make any bottom end power, and the rest of the build won't support high rpm power..... So you end up with a motor that's just kind of "flat" in the car.

I'm sure a few trips to the track will reveal where your combo sits.

Track is 90 miles away and I don't have a trailer (or a decent pickup that can tow it)... will have to depend on the butt-dyno for a while. Lots of straight lightly-traveled roads out this way.

Yes, I'm definitely aware that any chain is only as strong as the weakest link. My plan is to gradually upgrade pieces as money, time and interest permit, and I am on a budget. I do expect that the high end will be somewhat restricted even with a relative lack of low-end... for now. A decent set of heads is in the future when I have another $2500+ to sink into my toy. I am not looking for every last horsepower or tenth here, just something I can have fun with.

If I lose the PCV I can use the 3/8" baseplate port with an adjustable needle valve to get all the bypass air I need without drilling any more holes.

As we spoke, it's not an IDEAL combo w/that much duration, old style ported iron production heads,10.3 comp. and that carb so I'll get a stock looking DP dialed in w/adj. everything w/extra bleeds so you can tune all circuits if needed.............As far as timing, I like locked w/that much duration or super fast adv. but prefer locked and also am curious as to how much cranking comp. it has because it DOES matter and I now for the first time in years run a PCV valve w/a homemade oil seperator and I love it and only a few miles due to rain but intake/plugs are clean..........

Thanks for all your help, Dom. You're definitely teaching me more about carbs than I want to

Meanwhile I drilled a pair of 3/32" holes to the secondary throttle plates, about 1/4" in from the transfer slot/idle ports as instructed. Now it idles at 1100 (6" vacuum) or 1200 (smoother, 7" vac) with the transfer slots in the right place, the PCV system connected, AND the timing set at 24 initial! Sounds pretty nasty out back. Wideband dances a bit between 13.5 and 14 when fully warm. It does not want to idle consistently at 1000 or slower.

Opening the throttle to 2000+ (no load) makes 15" of vacuum which will certainly activate my advance can. Should I really limit it to only another 5 degrees?

I still need lighter springs in the distributor because it didn't sound like it was all in until well over 3000 (no helper available today to read the tach). Maybe reset the FBO disc from 10 to 12 deg while I'm in there (for 36 deg all-in if that's safe on pump swill).

Also I'm definitely going to install an oil separator in the PCV line. I agree that burning oil on purpose is generally a bad idea

Sounds like it's going in the right direction and I lock all my stuff out but that duration will be happier w/more lead at least most I've messed with...........