A little engine planning/cam selection help, please?

[nikwho]

Hey guys!

So, my little 383 small block is in my '59 Apache. All QA1 tubular control arms, disc brakes front and rear. Currently has a mild cam and World Products iron heads.

It's a hot rod/weekend warrior. 26"-ish rear tires (275/40-18), built TH350 (may swap to overdrive standard transmission in next year or two), 3,000 stall converter, 4.10 gears. Soon to be 4 linked. Currently has an Edelbrock Performer RPM intake. I just picked up a set of Dart Pro 1 aluminum heads. Pistons have a 5cc dish to them (flat tops with valve reliefs). Dart heads have 64cc combustion chambers and 200 cc intake runners. I'm considering this camshaft, as I've previously had amazing experiences with the Summit Racing house branded camshafts!
https://www.summitracing.com/parts/s...make/chevrolet

Considering swapping to either an Edelbrock Performer RPM Air-Gap intake, a Weiand Track Warrior single plane, or
Edelbrock Victor Junior single plane. Thoughts here?

Here the truck:

[nikwho]

Whoops. Here it is:

[Greasey Harley]

What is the compression ratio?
What is the quench?
How are you going to drive it?

[nikwho]

Don't know how I missed the CR. Thought that I typed it. It's 10.2 static. Have no idea what the piston to head clearance is. I have not measured. I'd say about typical of a 64cc Dart head and flat top +5cc pistons. I'm going to drive it like I stole it. I like burnouts, track days, autocross and hot rodding it around.

[burnin oil]

That cam should work pretty good. The only thing that I don't care for personally is the 114 centerline. I prefer a tighter angle but I drive a stick. Being a nitrous cam i am betting that it will have slightly higher cylinder pressures and better vacuum since they try and trap the intake charge a little more that a NA setup.

[nikwho]

Yeah, I was also thinking about that. As I was talking myself in a roller cam this morning, I was watching episode 16 of Engine Masters. They compared a roller cam to an Isky HFT cam. Toe, the results truly spoke to the HFT camshaft! The engine was a 400" stroker with 10.3:1 compression. It ran hard to 7,000 RPM! MADE 487 lb/ft. of torque at 4700 rpm and 496.1 HP at 6200 rpm. Only down 6.4 lb/ft of torque and 21.4 HP from a hand selected roller cam! I'm considering giving this isky cam a shot! It's their 292 Mega cam.

Specs here at Isky's website:

https://iskycams.com/shop/index.php?...roducts_id=279

Nik

[burnin oil]

Alot of people have been beating on the the roller cam deal for the last few years. My personnel opinion is that they are superior to flat tapeets but only in max effort motors. What I am saying is that they do work better with new oils and extreme valve lift acceleration. If you you have a block setup for it by all means go for it. If not I would spend the conversion money elsewhere. Figure that a solid cam and lifters is $250. That alot of coin towards a super charger or turbo. For the money laid down the power adder wins every time. I built a dirt rack style 400sb 5 or6 years ago with a solid cam and lifters with a cam oil office that has barried the tach every time it's been out. I am a little bigger in the 250ish duration but it is stupid reliable. I have no issues with a roller cam but it is a huge investment compared to other ways of making power. Max effort I would do it in a heartbeat. On a budget I would look towards the turbo/ blower or more cubic inch motor. This is my opinion and others will jump in and say only racing oil will work in non roller motors. I just run looser bearing clearances with 15w40 diesel oils. No issues to date with wiping a cam. Ultimately it's your decision. My motor was a daily driver for 2 years in stop and go traffic(think going to a concert) and never had an oil liability issue.

[nikwho]

I think that I am going to run that isky HFT cam. I have been happy with my flat tappet engines, and have no issues running another! My reservations now are on the intake. I'm nervous that a single plane may hurt more down lower, than it will help up on top. Perhaps I should just swap my old Performer RPM for a Performer RPM Air Gap? I'm wanting to make as much power as I can in the 3,000-6,000 RPM range.

[burnin oil]

Keep the performer rpm. Great manofold for the street. You can play with spacers if you like. You will be happier with it over an air gap or single plane. Been there and done that. It's performer RPM or single plane. It's honestly the cross roads and it's rpm streetablity or single plane and no choke. This is where nice driving goes away for WOT power. Hint the air gap has driveability issues due to no heat to the intake charge.. good for HP but bad for streetablity. I am a single plane guy but at the price of sparkplug recently skyrocketing with fuel prices the RPM would be my Choice.

[nikwho]

Interesting! This may be the first time that I already owned what someone was suggesting that I run! LOL. I have liked this intake thus far on this engine with a 1" spacer! This engine is currently in the truck and driven a few times per week.

I figured that while I am already swapping heads would be the perfect time for a cam swap and to look into any other changes, that might increase performance. I wonder if this camshaft will increase the RPM enough to warrant jumping up from a 650 cfm carb to a 750? I've currently got a 650 cfm QFT carb on the engine, but the cam in it now pretty much falls on its face by 5,000 RPM & I also live at 6,800' ASL. It works well now, but thinking that with a cam that will run up to 6,500 or 7,000, I may need more carb...

Using the RPM X Displacement ÷ 3,456 = reccomended carb size formula:
Current cam - (5,500×383÷3,456= 609.51 cfm)
If Isky pulls to 7,000 (7000x383÷3456= 775.75)
If it pulls to 6,800 then a 750 should be about perfect!

Luckily, I have a brand new 750 cfm Quick Fuel carb on my boat. I'm building a new 496" BBC for my boat, that will require a lot more carb and will run two 650 cfm carbs. SO, I can swap the 750 cfm carb to my 383, and swap my 650 cfm carb to the new tunnel ram, and only have to buy one new carb! Win-win.

As soon as my new camshaft, head studs and head gaskets arrive, I'll get the new Dart heads and 750 carb installed and see how the Performer RPM does on the new combo.

[burnin oil]

The 750 should run pretty good but I don't have experience with your elevation. I ran a 830 on my 400 for years. When it had issues I threw a 390 I had on the truck and it ran so its been on the truck. Talking about loosing some umph! The 830 lost a little bit of torque off idle but not alot and was definatly back by the time your converter stall speed. When I get a chance the good carb is rebuilt but other projects are ahead of it. Still working on the 57s 4x4 conversion, the jeep ripped the track bar bracket in 2 so it needs the axle pulled and the brackets checked for alignment, and the house needs restained. Of course its been raining every 3 or 4 days so everything is muddy. I have been using plywood to get out of the mud for the last couple of weeks to try and get caught up. I need a shop! Been moving dirt to get a level spot for that also. On a side note the 390 carb and 830 get the same MPG, figure that out.