I'm in the early stages of building a Satellite police car clone.

I already have a 383 block, and I'm fairly certain I'll do a 3.75" stroker, making +/- 435 CID.

Here's the biggie: I'm going to run HP exhaust manifolds, because I want the engine to look stock.

Given the high RPM restriction of the exhaust manifolds, I'm considering a stock HP camshaft or an improved modern variant that will deliver similar idle quality, similar idle vacuum, and decent power at the low to mid RPM range. I absolutely don't want a lopey idle or low vacuum at idle. It seems that I read here that someone makes a modern take on the old HP cam, but I don't remember much else about it. Can anyone point me in the right direction?

I'm considering using some heads that I've had around for years: 452's that were done at Herb McCandless' shop before he closed down. They're fitted with 2.14/1.81 valves and got the valve pocket porting that comes with a 3-angle cutter. Nothing else except some port matching and milling was done to the heads. I wouldn't be adverse to spending the money for some stealth heads from 440 Source, but I'm thinking the exhaust manifolds will limit breathing to the extent that I would never see the difference.

Otherwise, I'm planning to use a Thermoquad.

Since the only thing I'm committed to so far is the 383 block, I essentially have a blank sheet of paper.

WWYD?

Thanks!

i would run this cam. given you have decent heads and are using the 3.75 crank, i'd imagine it would run great and the idle would sound about like a stock 440HP motor...

http://www.compcams.com/Company/CC/cam-specs/Details.aspx?csid=707&sb=2

It sounds like you are talking about Bob Karakashian AKA Mr. Six Pack's grind. You can call him 248-477-7776 for day, 248-489-4076 evenings or mr6pk@hotmail.com

I'd run the cheapie summit k6401. It's a little more aggressive than the stock HP cam but not a whole lot. My brother's got one in a 440 with stock heads and hp manifolds. Sounds good, just a slight hint of lope at idle.

I'd look into the MP .528 cam, AndyF has had great success using it with exhaust manifolds. Don't know if it'll lope in a 440 (basically what you're building)

But as there's no replacement for displacement, I'd look hard at a longer stroke using bigblock chevy type rods. Lighter weight is the #1 reason. Better/cheaper rod availability and the increased strength of 7/16" rod bolts is another.

R.

The XE 268 has some lobe in a 440! Major difference to stock!
Friend has one in a 1968 Chrysler 300, otherwise stock. It is even troublesome in stop-and-go traffic with the power brakes.

Theoretically with perfect ignition tune this could be softened, but in the real world you need to go milder if you want stock beahaviour.

Greets
flo

The mp .528 would be a good choice too, but also has a small lope at idle, and of course would require to upgrade to adjuster rockers.



I wonder if your friend had a poor tune or a lousy power brake booster. I ran the lunati voodoo 60303 in a 7.8:1 440 and the power brakes worked the same as they did with the stock cam. The 60303 has 2 or 3 degrees more duration @050 than the 268h. 383man on here ran the mopar .557 cam in a 440 and his power brakes were fine, and that's a heck of a lot more cam than a 268h. I think certain years and types of power boosters are better than others.

Thanks for the replies, guys!

The Comp Cam, on paper at least, does look quite similar to the old HP cam... possibly with some improvements as camshafts have come a long way since then.

I have a brand new k6401 cam, timing set and gasket set, etc. if your interested that I'm no longer going to use (my block was cracked...so ended up going with a small block). Make a package deal...if your interested, PM me.

Rob

i'm running a summit 6401 in a 440. nice smooth idle, a little less vacuum than stock, very good torque. pretty sure they're a crane 280/290hp lobe profile. there's a 1l2lsa version of it, elgin 988p or clevite 229-2034. i've ran a hughs/engle 23/30 (engle k56 intake lobe/k58 exhaust lobe) and it's pretty good. truth is i wouldn't be afraid of an old stock magnum cam with some 1.6 rockers.

If running a bit more cam that stock you will likely need a bit more initial ignition advance... and shorten the slots to keep total mechanical advance in the 34-36 degree range. The higher initial helps idle vacuum and helps clean up the idle with a bigger cam. More cam = more initial advance.

Check the Hughes or Howards cams websites, they have some better lift values than the likes of the comp ones, If you wish to use stock rockers, remember that they are closer to 1.4 ratio than 1.5. So a cam in the .520-.530 lift range is actually just under 500 with the std rockers

JimmyG the JB weldmaster. I'd also second the 6401 cam and I would mill the open chamber recesses flat/same depth so you can achieve .035" quench with the right piston (keep SCR conservative) which will give you the MOST EFFICIENT long block no matter what you do/add/modify on or around it. any carpenter will say that the most important part of any structure is the foundation

I would run a different head, the big block open chamber heads are horrible no matter how you slice them and since you say you have a clean sheet of paper it makes little sense to use them. There is really not reason to use them unless you are racing in a class that requires them. It's hard to build compression with the the 4.25 bore, you want a piston at zero deck and a cylinder head with under 84cc, the 452's, unless they have been cut a bunch by Herb, are going to be 90cc or more. I did a quench build with 452's, what a nightmare.

As far as the restriction from the stock manifolds, gasket match the port entrances, open up the outlet to 2.5, make sure your headpipes are centered to the opening. AndyF made 570ish HP with a 470" low deck stroker, ebrock heads and stock HP manifolds he didn't do much of anything to.

Then there are F.A.S.T. racers running into the 10's with them.

I do have a set of 915 rebuildable cores, and I'm not adverse to putting out the price for a set of stealth heads.

I was under the assumption that for a quench build, the pistons would have to be flat topped at zero deck height or thereabouts, and the head gasket would have to be really thin (or positive deck height to compensate). Anyhow, I just did a quickie calculation using 4.28" bore, 3.75" stroke, 0 piston dome, 0 piston dish, 0 deck height, .019" thick head gasket, 4.40" head gasket bore (I guessed at this), 80cc combustion chamber, and came up with a CR of 11.43. Either I did something wrong or this sounds just a tad high to me!

It sounds really high for 3.75" stroke... also for pump gas. Quench can start with either a flat top or a "D dish" with the flat part of the piston lining up with the flat part of the head.

With either, zero deck on the piston and a .040" head gasket will get near perfect quench with a 915, Edelbrock RPM or Stealth head. Remember to allow for the piston notches which are usually at least 4cc and may be bigger.

The math was correct (1) using JB Weld on dist slots (2) stroker pistons for your app will have a dish as opposed to a flat top & 18 CC for instance would get it down to 9.6 CR (see what CC's the pistons for that app have). You would bore/hone then mockup the rods/pistons in the corners & see what the height is then mill/square deck as needed/along with the math

You would need a .039 gasket with a 4.41 bore, if you were 0 deck it would be 10.85 with an 80 cc combustion chamber and no valve notches. Your pistons don't have valve notches? They would knock you down to about 10.25

Actually he ain't got em yet (& they will have a dish, my buddy Jimmy is just doing some bench racing upstairs!

[/quote] (1) using JB Weld on dist slots... [/quote]

Man, some things you just never live down. Sigh.

And Robert is right, I don't have anything but an unmachined block and some exhaust manifolds yet. I'm asking questions early so I can hopefully put together a decent engine.

So I was looking at a 440 Source stroker kit, and their pistons have what is basically a deformed D shaped dish, and they advertise that they keep a tight quench. But with a thicker (.035) MLS head gasket (now required because it appears that I'll be using their aluminum heads to build a quench engine) I came up with a CR of 9.0:1; their flat tops with 4 cc valve relief notches and a .035" head gasket brings it to 10.4:1, which sounds about right with aluminum heads.

Did I miss anything?