75mm t/b will it fit

[LEE93COBRA]

You match the cam to the head flow numbers.

Is that in response to my post?

 

[9 deuce gt]

LEE93COBRA:

This is exactly where I had hoped this thread would go. To answer your question about the cam, my answer is....I don't know. LOL. You aksed the question exactly the way I couldn't get it out originally. Is there more performance to be had out of the AFR 165's? On other boards I have asked this question, and the answer I get is that the heads flow ~250 cfm. Use the Cobra intake, ported to flow ~250 cfm, and pick a cam that offers low end torque, usually with ~ .500 lift. This is supposed to be the street setup to have. (obviously you want a more track oriented combo) But my question here is where do you draw the line. Can you run a track, high RPM setup on the street and be happy. Is there going to be too much of a trade off for low end punch? Is it all in the gearing? How can you get all of the potential out of these heads. There is a lot of hype surrounding these heads, so why not try to wring out the power?

Here is how I see it, right or wrong. The heads flow ~250 cfm at .500 and continue on to .600 lift. If the intake can support this, why wouldn't you get a cam that is making it's power at .500 lift? Would the setup be radically different if the cam was supporting max lift at .600? How would that feel on the street with the right supporting cast? On another note, what IS the right supporting cast? Do you neccesarily need to have better flowing components at .600 lift? Would the intake have to be hogged out? Would the 75mm T/B be needed, or would the 65mm T/B support enough flow to get the desired times? These are questions I do not know the answers too.

 

[9 deuce gt]

Let's look at my setup:

AFR 165's
Ported Cobra Intake
TFS stage 1 cam
1.6 RR
30# injectors
80mm Mas air
65mm T/B
1 5/8" eaqual length headers
O/R H pipe
2 chamber flows
3:73's


This combo is great on the street. Forgive me, I have no idea what time it runs. But for conversation sake, let's say it's average for this type of combo. I love the low end, but it seems a little soft on the top end. Traction is a joke. I would like to see a little more power on the top end, but on the other boards when this question is posed, the answer is that this type of combo is destined to run like this and only like this. So my question is, can I gain more with these heads, or do I need higher flowing heads to get the top end I'm looking for? How would a higher lift cam change the results if I changed nothing else?

 

[LEE93COBRA]

LEE93COBRA:

This is exactly where I had hoped this thread would go. To answer your question about the cam, my answer is....I don't know. LOL. You aksed the question exactly the way I couldn't get it out originally. Is there more performance to be had out of the AFR 165's? On other boards I have asked this question, and the answer I get is that the heads flow ~250 cfm. Use the Cobra intake, ported to flow ~250 cfm, and pick a cam that offers low end torque, usually with ~ .500 lift. This is supposed to be the street setup to have. (obviously you want a more track oriented combo) But my question here is where do you draw the line. Can you run a track, high RPM setup on the street and be happy. Is there going to be too much of a trade off for low end punch? Is it all in the gearing? How can you get all of the potential out of these heads. There is a lot of hype surrounding these heads, so why not try to wring out the power?

Here is how I see it, right or wrong. The heads flow ~250 cfm at .500 and continue on to .600 lift. If the intake can support this, why wouldn't you get a cam that is making it's power at .500 lift? Would the setup be radically different if the cam was supporting max lift at .600? How would that feel on the street with the right supporting cast? On another note, what IS the right supporting cast? Do you neccesarily need to have better flowing components at .600 lift? Would the intake have to be hogged out? Would the 75mm T/B be needed, or would the 65mm T/B support enough flow to get the desired times? These are questions I do not know the answers too.

At 600 lift, better heads such as the 185's and probably trickflow would yield significant better power results but in my opinion, only if you have more cubic displacement. Also when running a large cam like that, there is no way 65mm t/b would work. It would be a bottleneck choking it down. I have heard and seen a 70mm t/b show gains on a mildly modified 302. Remember too, that on average the larger a cam is the more it will be centered for upper rpm power and it may require a rear gear ratio change. Is that bad daily driving, not necessarily. Look at mod motor cobras with 4.10's, the tach reads a little high at interstate speeds but it doesn't 'feel' like a big deal because they are no longer in a 'lug' mode where you are wondering if you should downshift to keep it in a good cruising rpm.

My opinion though is if the the heads flow 'x' amount from .500-.550, why not take advantage it. To me if you only center around .500 lift cam and the system is just starting to flow, then you are leaving power on the table. Hell, you pay $1200 for this equipment, use all of it that you can.

Lets review my combo I am going to have now...

Forged 306
AFR 165 heads
AFM N-61 cam
Ported lower and gasket matched OEM intakes
Accufab 75mm t/b
PMAS 80 mm MAF
30# injectors
4" n/a AFM power pipe.
4.10 gears

While it may not seem that way, my car is going still be in the daily driver category (I hope) I drive my car a good bit (bought it 9 years ago with 80k miles it is now at 180k miles) I retain all creature comforts plus stereo system complete with a spare tire well sub box that a friend of mine made a few years ago. I do take it on some 800-900 mile cruises in the Smoky mountains 1-2 times a year

-but-

yes it will and does see track time every chance I get. I love to go racing.

Back on topic...

I spoke with Rick Anderson a few times over the last 5 weeks or so telling him what I wanted at the track while the car kept good streetability. I told him what I had (the heads, full weight car, etc..) and he is the one that told me that I would be happy with that cam and that it would REQUIRE the use of a 75mm t/b, 30# injectors, and the big power pipe. I also explained to him that I would like to keep the shift points below 6500 rpm to help with longevity of the motor. Thought about his suggestions for a week and then ordered the parts.

 

[racerbox77]

Heres my question- what are the flow numbers for the 165s. My father told me that with a turbo or supercharged car you would want the 185s or 205s depending on boost level and c.i. ,and thats what your going to do right Lee?
By the way my Dad is an engine builder and won the fastest street car shoot out in Ohio a couple years ago. Heres his site. www.boxperformance.com He is great at porting heads "thats where the power is."My 89 LX full weight daily driver went 111mph in the quarter. 302, N/A with stock ported heads, GT40 intake, B303, 77mm Prom with 4:10 and unequal shorties, H pipe and Dynomax. This was 10 years ago.....Just reminising.. Check out his site its pretty cool.

 

[LEE93COBRA]

Here is what AFR claims http://www.airflowresearch.com/165sbf_sh.php

I'll agree that heads is where its at but you got to have cubic displacement to justify having a big head

 

[racerbox77]

Here is what AFR claims http://www.airflowresearch.com/165sbf_sh.php

I'll agree that heads is where its at but you got to have cubic displacement to justify having a big head

Or boost.

 

[9 deuce gt]

Lee, tell me if you think this is right: It's not all about the intake flow compared to the heads. Yes, you want them to be matched, but having a higher flowing intake is not necessary. It's about where the cam is making it's power. I believe what you are saying, is that having a cam with just .500 lift will give you great low end torque, but will be out of gas early in the RPM band. Having more lift will raise the RPM band, but get you into the sweet spot of the heads flow when the gearing is correct. Is this the way to maximize potential of these heads?

 

[cobra93]

believe what you are saying, is that having a cam with just .500 lift will give you great low end torque, but will be out of gas early in the RPM band. Having more lift will raise the RPM band, but get you into the sweet spot of the heads flow when the gearing is correct. Is this the way to maximize potential of these heads?

This really isn't the case, guys. At these power levels, and these head flow numbers, lift is not nearly as big a player as duration. A good example of this is the three Anderson cams at the following link: http://www.andersonfordmotorsport.com/dynojet/50-cams.html#hi-rev

Lift is the same, but duration is increased with each step up in cam. See how the max achievable rpm is driven by duration? Another example is the NMRA Pure Street cam. Max lift is 0.500" with no limit on duration.

 

[LEE93COBRA]

This really isn't the case, guys. At these power levels, and these head flow numbers, lift is not nearly as big a player as duration. A good example of this is the three Anderson cams at the following link: http://www.andersonfordmotorsport.com/dynojet/50-cams.html#hi-rev

Lift is the same, but duration is increased with each step up in cam. See how the max achievable rpm is driven by duration? Another example is the NMRA Pure Street cam. Max lift is 0.500" with no limit on duration.

that is very true Marc but am I wrong in thinking that you want lift to play a factor too in regards to using more flow of the heads. I understand that duration is keeping the valve open longer but if your best flow # is at .525 lift and above wouldn't you want your cam lift go up that high?

Now that i think about it, I guess you could keep lift at .525 hold the valve open duration longer and you would get max flow out of the heads.


hmmm. Great discussion guys.

by the way Marc, its about time you came back into this thread

 

[9 deuce gt]

Okay, because I'm a little dense, LOL, can we examine my setup. This is by know means a thread HI-JACK. I just would like to understand this.

My combo:

AFR 165's
Ported Cobra Intake
TFS stage 1 cam
1.6 RR
30# injectors
80mm Mas air
65mm T/B
1 5/8" eaqual length headers
O/R H pipe
2 chamber flows
3:73's


If I wanted to keep:

AFR 165's
Ported Cobra intake
1.6 RR
80 mm MAF
1 5/8" headers
3:73's

What can I change to get the max out of the heads? It looks like I could go with a bigger cam, (duration and lift), and a bigger T/B. I would like the car to retain some low end, although with the 3:73's traction is now an issue so losing a little on the low end would be fine. I would like to shift around 6200 RPM's. It is a full weight street car.

Basically what I would be looking for is a little more mid-range to top end pull. Can this be achieved with the parts that I would like to keep?

 

[LEE93COBRA]

LOL.. Add a N-61 cam, 4:10's (going in the car over the next 2 weekends), 75mm t/b and you will have the same setup I am building

 

[cobra93]

I have been away switching back to 4.56's. The 4.88's were too much gear for the new combo this year. Vlaves are floating at just over 8,800 and I figure it will run 142-144, putting me at 9,200 at the stripe!

But back to the thread. I had to go back and look at my stock shortblock combo as it has been a while. I made peak rwhp of 312 at 5,600. (Shoot, we don't start my pulls these days until 5,500). Sorry, back to the thread. I looked up my head flow numbers from the AFM Stg III and we are talking
0.500 289 193
0.550 296 198
0.600 301 201
so you guys can use these numbers for reference. That was at 28" and no pipe on the exhaust. I remember the cam I had in there was a predecessor to the hi-rev stuff, but it did make +17rwhp at 6,000 over the Crane 2031 I had in there previously. So yes, I feel there is a bunch more power in the cam, deuce.

I would maximize the lift you have available because this will not effect driveability. Then, for a street car with pump gas compression ratios, the trade off will be how much duration you can live with on the street. I think Lee's choice with the N-61 is a good one. Now what he should really do is borrow those 4.88's and my latest Hi-Rev cam (only has 335/353 degrees advertised duration). J/K. I know Rick has tried a bunch of these cams in his street coupe, and will know how much is too much for the street.

 

[9 deuce gt]

Okay, so it looks like I need a bigger cam. I guess AFM or a custom cam would be the way to go.

"I would maximize the lift you have available because this will not effect driveability"

When you say this, are you talking about a cam swap, or is there a way to do this with my existing cam...maybe 1.7 RR?

 

[cobra93]

I assume you have stock pistons. If you know how much p/v you have now, you can make a quick calculation and see where you will be with 1.7's. That would get you 6% more lift the easy way. The big power increase will come with the cam lobe design and duration events in my opinion. If I were you, I would wait and see how Lee likes his N-61... But yes, there is power to be had with a cam swap over what you have.

 

[LEE93COBRA]

If you are still running stock pistons you will have to watch what cam you go with. I am pretty sure that the cam such as I have would be to much to go with stock pistons. I doubt that the there is enough valve 'relief'

 

[racerbox77]

I have a bone stock long block with an s-trim 10psi. What kind of cam you guys think I should go with? I hear the E cam any others? I know with a blower car you dont want a lot of duration.

 

[LEE93COBRA]

My b-31 cam worked well and I have it for sale :-D

 

[racerbox77]

what are the specs Lee