I value your opinions: 360 Street Setup

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nyman72scamp

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Here's what I've got:

1972 Scamp, 727 trans, 4:10 gear sure grip, 15in wheels.

1974 360 Block .060 bore. Stock bottom. Look to be stock pistons. I'll be using thin head gaskets, aprox .028 thick.

I've got a thermoquad carb and a edlebrock torker II manifold. I'm open to changing these but would like to keep them to get started.

I'll be running full length headers with 2.5in pipes.

I've got cast heads #3671587 slight porting and gasket matched (so I've been told, bought at swap). Three angle valve job, MP Springs P4120249.

I've got two options for cams: I've got a MP 508 cam that I can run with hydraulic lifters and stock rockers. I would likely use a 3000 stall converter.

Or I have a Comp 270S cam with the solid lifters and I've got stock 273 adj. rockers. I would likely use a 2400 stall converter.

I plan on using this car for cruising, car shows, ect. Want it to turn the tires at will and would like it to feel strong in the mid rpm more than at high rpm. Kinda want it to pin me to the seat when I stomp the go pedal between stoplights - not that I plan to street race. It's always cool when the car idles choppy but not necessarily more important to me than a good reliable street cruiser.

So, anybody want to choose my cam for me? I would also appreciate any other advice but keep in mind that I'm not able to spend much more and would like to start this project with what I've already got. I could add down the road so keep that in mind.

Thanks for your support.

I
 
Ditch both cams in favor of the factory 340 cam from Mopar Performance. Toss the intake and get either a stock 340 intake or an Edelbrock Performer 360. Use the Thermoquad. Lose the 4.10 gear and get some 3.23s. I ran a best of 13.6XX in a 71 Dart with a stock unbored 360, stock pistons, stock 1.88 valve heads, iron intake, thermoquad small tube headers, a mild crane cam 904 and 3.23 gears. It got over 20 MPG too. You'll need that as gas prices are fixin to take a big jump. You better think about those gears. That engine will pull like a ***** in church just fine in that light car with 3.23s.

Amazingly, Summit has the Carne cam in stock I ran, so it will be better than the 340 cam.

http://www.summitracing.com/parts/CRN-693802/
 
Need more info. like is this engine apart?? why bore it over 60 over and use stock pistons?? have the rods been resized?? crank ground?? you need arp bolts on the rods at least, IMO the torker is not a good choice I had one its more of a strip manifold, not too good for a street motor, you need a dual plane manifold, the comp cam should be ok. I like carter carbs, whether afb avs or themoquad, think your good there,
 
If those are the choices, the Comp 270S would be my first. If you are open to other choices the Comp XS268S would be my first choice overall. In either case, use the 273 rockers and make sure teh pushrods and preload are set right.
 
412stroker, I think it is allready .060 overbored.

moper said:
If those are the choices, the Comp 270S would be my first. If you are open to other choices the Comp XS268S would be my first choice overall. In either case, use the 273 rockers and make sure teh pushrods and preload are set right.
Click to expand...

Ditto.

If you only have a TQ carb and the TorkerII, the carb adapter will add about an inch (With gaskets under and above it) making hood clearance an issue I beileve.

When the time comes, I would look for a Weiand Action plus since it has a spreradbore TQ freindly carb pad. The idle to 6000 RPM range of this intake is well suited for the performance perameters you have set up and given. The intake is no slouch. I like it better than the Edel. Performer.

How far down in the hole are the pistons and how many cc's are the heads? Stock uncut deck?
 
Thanks for your interest and feedback. It's clear you guys know your stuff.

To clarify:

The engine I bought was already bored .060 over. The lower parts are still assembled but the top end is off the engine. The bottom end, pistons and cylinders look fine for now. I don't plan on taking it apart further at this point. My plan is to put this thing back together to get it on the street. I'll be building another engine over time so my goal is to keep it simple and inexpensive at this time. I already have all the parts I listed so I'd like to work with what I have if possible. I am willing to buy something if it's really necessary. If any of you had a strong objection to the parts I've got I would consider spending money. So unless what I've got will flat-out not work together please let me know. I appreciate your feedback on that.

I have to assume the bottom is all stock rods and crank. I also think the deck is uncut, and the heads are likely uncut.

I think the compression will be around 9.5 It looks like the deck height is around .170 (does that sound possible, I did measure it a while back but I'm going on memory here). The stock heads are probably around 65-72cc chambers.

So given the additional information I just provided, along with my initial list and the opinions I got from you guys it sounds like I should initially:

Use the Comp 270S cam
Use the 273 Rockers
Use the Torker II and thermoquad

What about my stall? Nobody said anything about that. I can also look for a different set of gears for the rear.

Good job people!
 
nyman72scamp said:
What about my stall? Nobody said anything about that. I can also look for a different set of gears for the rear.

Good job people!
Click to expand...

Sorry, did you previously ask about stall speed and/or gears?

You mentioned 4.10's in the car now. (Correct?)

A factory high stall converter would do well. That cam is a 1800 - 5800 rpm cam. If you don't have a converter, a 2000 - 2200 stalling verter would work well IMO. More if your racing it.
 
Again, thanks for your feedback. No, I didn't specifically ask for stall information, I did mention that I was considering something around 2400 and when no one mentioned it I was just curious if it was over looked. Maybe it did not get mention because it was the only thing unobjectionable.

Since I really expect that 90% of my driving will be under 60 mph I'm hoping the 4:10 gears won't be too bad. How do I find out what the tranny gears are?
 
Unless the transmission has been modified, I'm pretty sure the ratio in 3rd is 1:1. I could be wrong. Makes sure if you use the 270S cam, you have the right springs for it. For rear-end gears, 4.10 is steep even if you stay below 60. They will suck you back in the seat like you want, but even around town, they KILL any kind of gas mileage. That's why I don't "cruise" my Duster much anymore (it has 4.10's). 3.23 or 3.55 would be good. I wouldn't go higher than 3.23. I have 2.79(?) in my Barracuda, and they suck.
 
2400 would be fine I think. The 4.10 I have traveled far with and the drone gets to me from the exhaust before the rev's bother me. Alot will depend on actual tire diameter. In example, a 235/60/15 is right about at 26 inchs in diameter. Going smaller revs the engine up at 60 and of course, bigger will have the engine turning slower at Hwy. speeds.

This will also effect how fast it gets off the line. But we knew that. ;)

Also converter slippage is a factor. I can not calc it in. But on my 4spd Cuda, it is a direct link and all locked in and working togther as a mechanical linkage gets. The vert will slip a bit. Just a little bit. The more efficent the less slip.

It's been awhile since I had the car out. IIRC, and thats a laff in itself after a few years, but I do remember somewhere around 3400/3600 RPM @ 60 mph.

I was also runig the Purple 292/.509 cam.
 
Rumblefish, you make a great point. I would get real tired of the exhaust drone pretty quick. I've got to make a decision about changing that rear gear. I've been cruising the site reading the posts on wheel/tire size. This project car came with a set of NIB Cragar SS 5 x 4 wheels, a spring relo kit and SS springs. The rear wheels are 15 x 8 and fronts are 15 x 7. I don't know the offset on these wheels so don't even know if I'll use them...but all that to say I'm thinking about tire diameter along with the rest of the package.

Alright then, thanks to all for your interest and feedback. Hope I can add value some day.
 
I would go with the 270S cam, make sure the 273 rockers don't rub the valve springs or retainers. I would guess that a .060 over 360 would be fine with a stock converter & the gear you have.
A dual plane manifold might be better but a single plane worked fine on my 360; if you find you need more low speed torque try putting a divider in the single plane plenum - under the carb. I've had good luck with Thermoquads.
 
Agree with most advice already provided. The cam choice is pretty critical, especially given your street use. I would go with a 340 cam grind ( good overall power ranges) and ditch 4:10's for 3:55 or 3:73.

Good luck...keep us posted
 
If you want to run the 508 Mopar cam, you will need a bit more stall than 3000. The compression has gotta be fairly high as well.

Why not the Mopar 528 with the 273 adjustable rockers?

Edit: Scratch that..I just read about the fairly low compression..I'd get the 450/455 Mopar hyd. cam. That would be a nice combo on the street.
 
nyman72scamp said:
Thanks for your interest and feedback. It's clear you guys know your stuff.

To clarify:

The engine I bought was already bored .060 over. The lower parts are still assembled but the top end is off the engine. The bottom end, pistons and cylinders look fine for now. I don't plan on taking it apart further at this point. My plan is to put this thing back together to get it on the street. I'll be building another engine over time so my goal is to keep it simple and inexpensive at this time. I already have all the parts I listed so I'd like to work with what I have if possible. I am willing to buy something if it's really necessary. If any of you had a strong objection to the parts I've got I would consider spending money. So unless what I've got will flat-out not work together please let me know. I appreciate your feedback on that.

I have to assume the bottom is all stock rods and crank. I also think the deck is uncut, and the heads are likely uncut.
Click to expand...

That's cool. The stock stuff will withstand probably 400 HP. I say only that because we don't know which rod bolts you have. If they are good ARP bolts then that figure would be about 550 HP. Nuthin wrong with a stock Mopar bottom end.

nyman72scamp said:
I think the compression will be around 9.5 It looks like the deck height is around .170 (does that sound possible, I did measure it a while back but I'm going on memory here). The stock heads are probably around 65-72cc chambers.
Click to expand...

I think that's wishful thinkin by a long shot. 8.7:1 at best with a thin head gasket and that 65cc small chamber....might not even be that much. That 170 deck clearance is killin you.

nyman72scamp said:
Use the Comp 270S cam
Click to expand...

Nope. WAY too big IMHO. again, with static compression as low as possibly 7.9:1, this cam will suck the life right out of it. Believe what the others say if you want, but this is way too much cam for what you have.


nyman72scamp said:
Use the 273 Rockers
Use the Torker II and thermoquad
Click to expand...

These choices are fine although a better choice on intake IMO would be the stock 340 piece. You'll lose some bottom end with the Torker.

nyman72scamp said:
What about my stall? Nobody said anything about that. I can also look for a different set of gears for the rear.

Good job people!
Click to expand...

If you build the rest of the engine to match the bottom end (like you should) you'll not need a stall. With that compression, if I were you, my goal would be to build an E58 360. Like the Lil Red Express Trucks had. Basically a stock 360 with all the 340 stuff....cam, heads and all. It will be a stump puller off the line and all the way to 5000 RPM. You will probably never rev much past that on the street and if you use that factory 340 cam, it pulls to 5800 and a little more. I promise you, use that Comp 270 and you will regret it. You don't have the static compression to support that camshaft. The 340 cam is by far a much better design for what you have.
 
I'm glad you guys keep coming with your opinions. I'm actually surprised that anyone is still looking at this thread. I may reconsider replacing the pistons to bring up the compression ratio. That would be preferred over milling the heads I'm thinking. I'm going to cc the heads to see what's there. I'd love to find out that I'm way off on the volume. I'll post my update here. Thanks.
 
I also realized that I don't have the Torker II manifold. I have the Torker 340. Is that worth keeping? Is there much difference between these manifolds? Sorry for that misdirection on the intake.
 
The intake is worth keeping for now. Many will just spend your internet money since you have millions and say, "Get a RPM, a Air-Gap is the best, and don't forget......."

The problem with the torker intakes are they start at 2500 rpm as a low point inthe power band. If your cam is rated to operate in the 2500+ rpm range as a low starting point, then the intake is OK. If the cam makes power below 2500 as a starting point, then perhaps, later, you can look for a different intake. For now, use what ya got and worry about the rest until later.
 
I cc'd one of the chambers on one of the heads last weekend. I'll do some more this weekend but the one I did cc'd at 68cc's. It's about what I thought it would be. When I plug the variables into a compression calculator it looks like the CR will be somewhere in the low 8's. That kinda bums me out so it got me to researching milling the heads. It seems like it's safe to mill them a max of .060. I would like to bring the compression up to the low to mid 9's. If my target was to lose 10cc's from the combustion chamber I would end up with 58cc's. The formula I found says to mill .0048 for each 1cc. Also need to mill .0095 of intake face of head for each .0048 milled off the head surface. Will there be any problems if I do this? Would you guys/gals recommend this be done? If you'll recall from the beginning of this thread that I was wanting to keep the cost down on this engine and save the money to build another one later. I know an option is to change the pistons but the are relatively new so thought I'd leave them. Let me have it people. Thanks.
 
It all depends on the milling cost really. There's no problem so long as you cut the manifold side too, but bear in mind cutting the intake side loses the valve cover sealing rail. I dont like to cut too far into the intake side more than about .030 just because it also messes up the way some valve covers sit over the intake runners. Sometimes the valve covers need to be trimmed to seat properly.
 
I'll tell you what I would do with it if it was mine. I would run the 340 cam and build it as is. It will surprise you how strong it will be. You need to remember, torque is what moves the car. 360 cubes even with 8.2:1 compression properly cammed and inducted and exhausted will make an A body move on the street. While you are enjoying that, you can be saving up for some good pistons and build a barn stormer the next go around.......that is IF you're not satisfied with it like it is. It's funny to me when people start talking about all this. These engines were low compression from 1972 on and yet, they were some of the fastest production cars of their time. The Lil Red Express Truck in 1978 even beat out the same year Corvette. The E58 is a PROVEN combination. Rather than ditch new pistons and prolong the build, that's what I would do. But what do I know? All my 71 Dart with a 8.2:1 360 would run was 13.60s with a 3.23 gear.
 
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