AFR 165 Advice
 

I'm looking to bump up the power in my '87 302 truck block based BDR. It currently is stock with a Air Gap Rpm manifold and 625 Demon Carb.
From what I seen and read, I'm sold on the AFR 165 heads my application. Still debating as to the stud vs pedestal heads (see earlier tread).
The pedestal heads would let me get started without new rocker arms ( could add at a later time if needed).
Debating just doing heads now and cam later or all at once.
Has any one added the AFRs without a cam change?
Can I do a cam upgrade later without removing the heads?
As I am not looking for a 6k + motor, will I be OK with the factory rockers (non-roller)?
Thanks for the input (again).
John B

Spending big bucks on new aluminum heads, and not upgrading your cam at the same time seems kind of inefficient. I'm going through the same exercise right now, using Trick Flow Twisted Wedge heads, a new Racer Brown custom grind cam, and comp cams pro magnum roller rockers. Also a new Speed Demon carb. Was going to go with AFR's but was advised that I would have to slightly modify my exhaust system, compared with not having to make any mods with either TF or Edelbrock.

The new cam is very inexpensive in relation to the investment in the heads, and it will really make those new heads work. You really NEED the new cam if you are going to take advantage of the increased air flow capability of the AFR's. You need to make sure that your intake will provide sufficient airflow for your new heads, and that the cam will provide the power curve to optimize the heads performance. The AFR's and Trick Flows have fairly similar flow rates (from the charts I've seen) and they both provide a nice incremental boost in both intake and exhaust flow up to .50 to .60 lift. So your new cam does not need to be radical. The stock cams in the 302 HP were rollers with 209 duration @ .50 and .444 lift. (that's what I've got). I'm upgrading to a Racer Brown 222 duration @ .50 and .500 lift. The increased duration and lift will allow me to take advantage of the TW's airflow.

Do the research, make sure your intake can feed the heads, and make sure you've got enough cam to take advantage of the heads flow. Then you will be optimizing your motor design in a balanced manner. Then drive the daylights out of it!! Have fun. Rick

Rick, good points about how a new cam will really "wake up" those new heads. But even the heads alone should provide a nice boost in power, do it in "stages" if thats what the funding dictates.

I'm curious as to what "exhaust" modifications were suggested for the AFR heads? I've seen applications on the 302 where it was straight up and down remove and replace, done!

Myself I prefer the AFR165's for a 302, all though the Twisted Wedge do flow more CFM, it's happens at the high end of the rpm range. I suspect AFR165 offers more "over all streetability" up to the 5800-6000 rpm range.

The cam can be swapped out later without pulling the heads. If I were doing it I would consider going with a higher ratio rocker arm to increase valve lift. A "poor mans" way to a bigger cam if you will. Careful using a bigger cam AND a bigger rocker ratio, valve clearance issues may come up.

My AFR 165 heads are bolted to my stock BDR headers. I really like my heads and with even a mild cam they really rock.

later dennis

John;
Save your money 'til Winter sets in and do it all at once.
Bill Stradtner

Since I have been pondering the same thing and doing alot of research, you are better off changing the cam too! The cam in the motor, if its truck based, is very weak and low end torque based. It will not be able to take advantage of the new heads. They will be providing a ton of flow that will go no where since the cam wont let it happen. You could change the heads, but when you change the cam to a roller, you are going to need to new lifters and pushrods, which will force you to remove the heads, so you might as well do the whole thing at once.

Best of luck,

Bignoze

All, thanks for the advice. Can anyone tell from this photo if this is a roller?

Yep, that's a roller motor alright.................

David

The swap off for your original question are basically as follows;

The pedestal mount rockers are technically non-adjustable. So, if you do swap your cam out, you will have to dance around with pushrod lengths to get the adjustment correct.

Also, should you intend to go to the stud mounts later, you will need to ante up for the machining to convert, although Comp does have a stud with a 5/16" mounting "bolt".

The stud mounts are adjustable, so you can adapt for reasonable changes in lift without having to re-engineer you engine.

You will also have to make sure the valves are adjusted correctly for startup...

Going to 1.7's will provide no practical increases in H/P because the "gains" all come at max lift. The lobe profile is the same, and time (duration) typically means more to you than minor changes in the window.

Excaliber, I asked the Unique factory about AFR's and the Weaver's said they built a turnkey car that AFR's had been specified for on the 302 motor, and their stock header / exhaust assembly didn't quite fit and had to be modified. The headers bolted right on without a problem but something dimentionally was different so that the bend of the exhaust pipes had to be modified so it would mate with the hanger brackets.

They said they had no problems with Edelbrocks or Trick Flows and recommended I go that route to avoid having to change / modify the exhaust system. AFR's were my preference, but for second place, the Trick Flows edged out the Edelbrocks from a performance standpoint from everyone I contacted. I know the early TF's had valve geometry problems, that have been rectified. All of the flow test data I've seen show the TF's and the AFR's as having fairly similar flow rates up to .50 lift. The AFR's appear to be a higher quality piece, but the TF's, with Ferrea valves, competition valve job etc., should be a very good set of heads and provide excellent performance. Rick

Hi,
I thought I would add my .02 about the AFR's requiring modifications. I don't know if this is the case here or not, but the 165 and 185 AFR's have the exhaust ports in the stock location. The 205's and 225's have raised exhaust ports for better flow which probably would require some slight tweeking of the exhaust system for everything to line up. I don't know if this is the case on the Cobra exhaust or not but a friend of mine had experienced this same problem when going from the 185's to the 205's on his Mustang. He went from the stock heads to the 185's with no exhaust system modoifications but had to do some minor mods going to the larger heads. IMHO the smaller 165 and 185 AFR's should fit just fine.

Mike

Good call Rick. I too would have gone with Twisted Wedge as the performance level is so close to AFR. The LAST thing I want to do is "modify" some "little thing" that ALWAYS turns into a dam nightmare before it's over.

"Just a little mode", I hear that and RUN! :LOL:

Thanks all for the input. It sounds like I will be waiting till winter to do my head/cam update as I hate to have any down time when it's nice.
My manifold swap was pretty quick but this could take alot more time....I haven't swapped a set of heads in over 20 years (in a sbc).
John B