Best street heads?

[68keyblr]

I'm looking to build a great stoplight - to - stoplight street motor. This car will see little or no time at the track. I'm mainly looking for the street "fun factor" which for me translates into low end torque.

I already have an RMP AirGap manifold and Edelbrock 600 cfm carb. I'm thinking that the best heads for this scenario would be Performer RPMs. I've heard that the AFRs are not a good port match to the AirGap. Also, I don't want to lose low end torque for high RPM HP since this car won't be spending alot of time over 5K RPM.

 

[67GTCOUPE]

Dude:

Canfield 195's...........Period.

 

[Max Power]

The RPM heads will match up with the equipment you have nicely. The threads have steel inserts. They flow about the same as 165s for less money. For your listed requirements, I think the RPMs with the 1.90 intakes are a really good choice.

I know very little about twisted wedge heads, so "no comment".

 

[jerry S]

The RPM heads will match up with the equipment you have nicely. The threads have steel inserts. They flow about the same as 165s for less money. For your listed requirements, I think the RPMs with the 1.90 intakes are a really good choice.

I know very little about twisted wedge heads, so "no comment".

I have the RPMs with the 2.02 intake valve and the 1.60 exhaust valve. If you get these heads and later find yourself wanting just a bit more power, you can find another 40-50+ hp in them by sending them in for porting. These are what my flow numbers are supposed to look like according to Avenger Cylinder Heads after they are ported. These numbers are better than the "as cast" Victor Jr. heads and are about the same as the Trick Flow Rs. However, the CNC ported TW heads flow better.

Edelbrock 60259 head flow numbers Before CNC program

Intake/Exhaust .100" 70/57
Intake/Exhaust .200" 128/104
Intake/Exhaust .300" 183/142
Intake/Exhaust .400" 219/163
Intake/Exhaust .500" 251/170
Intake/Exhaust .600" 255/174

After the CNC program

Intake/Exhaust .100" 79/61
Intake/Exhaust .200" 145/121
Intake/Exhaust .300" 198/168
Intake/Exhaust .400" 241/178
Intake/Exhaust .500" 279/196
Intake/Exhaust .600" 284/205

I should pick up a few hp here and there.

 

[68keyblr]

I have the RPMs with the 2.02 intake valve and the 1.60 exhaust valve. If you get these heads and later find yourself wanting just a bit more power, you can find another 40-50+ hp in them by sending them in for porting. These are what my flow numbers are supposed to look like according to Avenger Cylinder Heads after they are ported. These numbers are better than the "as cast" Victor Jr. heads and are about the same as the Trick Flow Rs. However, the CNC ported TW heads flow better.

Edelbrock 60259 head flow numbers Before CNC program

Intake/Exhaust .100" 70/57
Intake/Exhaust .200" 128/104
Intake/Exhaust .300" 183/142
Intake/Exhaust .400" 219/163
Intake/Exhaust .500" 251/170
Intake/Exhaust .600" 255/174

After the CNC program

Intake/Exhaust .100" 79/61
Intake/Exhaust .200" 145/121
Intake/Exhaust .300" 198/168
Intake/Exhaust .400" 241/178
Intake/Exhaust .500" 279/196
Intake/Exhaust .600" 284/205

I should pick up a few hp here and there.

Thanks Jerry that's great info. Does the porting shift the power curve up the RPM scale? Or does it simply shift the power curve up at all RPM ranges?

 

[68keyblr]

The RPM heads will match up with the equipment you have nicely. The threads have steel inserts. They flow about the same as 165s for less money. For your listed requirements, I think the RPMs with the 1.90 intakes are a really good choice.

I know very little about twisted wedge heads, so "no comment".

That's pretty much what I was thinking. The smaller valves (1.90 as opposed to 2.02) should keep the torque curve down in the lower RPM ranges.

 

[68keyblr]

Dude:

Canfield 195's...........Period.

I was under the impression that Canfields where more geared toward a high RPM racing application. Do the 195's have strong low end torque? Any idea on typical TQ/HP numbers and RPMs? I know there's lots of other factors involved like cam selection, carb, etc etc but even general info is helpful.

 

[jerry S]

Thanks Jerry that's great info. Does the porting shift the power curve up the RPM scale? Or does it simply shift the power curve up at all RPM ranges?

a bit of both but it is also a function of your cam. My current cam stops making power at 6k rpm which is ok because my heads in their current form do not flow any more after .550 anyway. with the CNC program, the numbers keep climbing and with a bigger lift cam, you would see higher peak HP at a higher RPM as well as higher numbers at lower RPM. I expect to lose some low end torque but not enough to be worried about. The bottom line is that your average hp over your RPM range increases with the porting.

 

[302 coupe]

trick flow's. Best street head ever IMO, not a bad race head either. Small ports make for big torque and great throttle response.

There is a chart at the bottom of Stan Weiss's head page that shows displacement and cfm with respect to rpm of peak power.

also, think of lift as torque, and duration as horsepower. A cam with .600 lift and 190* dur at 50 will be a torque monster, but a cam with .480 lift and 260* dur at 50 will be a horsepower/hi rpm cam. When you increase both lift and duration, you increase horsepower and torque while also raising the rpm range.

With all that being said, a nice set of aftermarket heads would be almost a waste on a street only car.

 

[mustang6788]

Another vote for TW heads, if you want to spend the money I would go with the 185cc CNC ported TW. One of the highest flowing 185cc heads out. Also has good mid lift numbers for good mid range. Makes a great street head. For a purely street driven 302 185cc is probably the biggest intake port I would go to keep port velocity up.

 

[Hack]

Torque doesn't mean anything as far as how fast the car will be, but if you want more low rpm power, I think stroking is a better way to go than heads. It will cost more than heads, but with the correct tune and a stroker kit your car will have significantly more torque, as well as low rpm power.

The factory heads are made to flow below 5k rpm already. Heads that flow more will allow the engine to spin faster and will give the biggest gains at higher rpms. The same thing is true of bigger carbs and high rise intakes like the RPM. It's called RPM because it's for higher rpms. Get it?

Having said all that, you can gain some power with new heads, even at lower rpms. If you are really set on buying heads, you want to keep the runner volume on the smaller side.

 

[68keyblr]

trick flow's. Best street head ever IMO, not a bad race head either. Small ports make for big torque and great throttle response.

There is a chart at the bottom of Stan Weiss's head page that shows displacement and cfm with respect to rpm of peak power.

also, think of lift as torque, and duration as horsepower. A cam with .600 lift and 190* dur at 50 will be a torque monster, but a cam with .480 lift and 260* dur at 50 will be a horsepower/hi rpm cam. When you increase both lift and duration, you increase horsepower and torque while also raising the rpm range.

Thanks for the quick edjamacation Suddenly all of those confusing numbers make sense!!

And now for a random fact about Chuck Norris:
What happens when an entire nation rises against Chuck Norris? Ask the citizens of Atlantis.

 

[Max Power]

The same thing is true of bigger carbs and high rise intakes like the RPM. It's called RPM because it's for higher rpms. Get it?

The Performer RPM intakes have a stated powerband of 1500-6500, and have almost no drop-off to the regular Performer at lower rpms.

They make great power below 5000rpm, and much better power than the standard Performers. They are not stricty a high rpm head.

 

[68torinogt]

go afr theyre bench proven!

 

[Vinyl66]

Any of the aftermarket heads will work very well on the street from stoplight to stoplight. You would be pleased with any of them.

For extracting every bit of power at the track I would favor the Twisted Wedge or AFR's. Since you will not be racing it, I would try to find the best deal.

 

[Hack]

The Performer RPM intakes have almost no drop-off to the regular Performer (extra words removed)

Also, I don't want to lose low end torque for high RPM HP (extra words removed)

Max, I think your advice and the others' is good, but it's not what 68keyblr asked for. That was my point. I wasn't saying the parts aren't good or won't work, just that they sacrifice a little low end torque for high rpm power.

 

[Max Power]

Hack, very very little. If he uses a Performer intake, he might as well use stock heads. While RPM stuff is a little softer off idle, it is stronger from 2000-5000 rpm.

 

[68keyblr]

Thanks for the good advice guys. One thing I'd like to clarify here - is it true that the RPM Air Gap manifold is NOT a good port match for AFR heads? If this is the case then I'd be inclined to go with the Performer RPM heads which of course would be an excellent match. If this is a myth then that opens up the choices substantially.

 

[67GTCOUPE]

I was under the impression that Canfields where more geared toward a high RPM racing application. Do the 195's have strong low end torque? Any idea on typical TQ/HP numbers and RPMs? I know there's lots of other factors involved like cam selection, carb, etc etc but even general info is helpful.

The Canfield is much like a TW HIGH PORT head.

They have VERY high velocity port design..........they will work well and allow you to grow.

I have them on my 393..very impressed so far.

I had edelbrock rpm heads on my last 351w.I also was VERY happy with those, stick a TFS Stage 1 cam with them and it will scream.

BUT, for $1195.00 I got the Canfield's from Jay Allen at camshaft innovations, with Ferrea race series valves and the springs I needed! Edelbrock uses crapola Pioneer valves and springs.

 

[Bentworker]

I'd like to see someone build up a boss 302 or a 351 clevor with a set of CHI heads, would be neat to see a screamer 302.

I've got their 2V heads on my cleveland, should be run on the engine dyno in a week or two. I'll be sure to post the dyno results and a full spec sheet.