More money, more work. Hard.to justify

 

Ed talked me in to putting 195s on my 331 with one of his custom cams. Unfortunately I don’t have the exact information you’re looking for regarding a 302. All I can say is this combination is light years faster than the 306 with an additional point in compression, twisted wedge 170s and a custom Erson cam. I paid $1400 for the 0 mile 331 short block and assembled and installed it myself so that’s how I justified spending the extra money on good heads.

 

In-line valve reliefs only or?

I have both set of heads and I prefer the 11r because of price only. If given a set free, I would be happy with either set depending on my valve reliefs.

both my 363’s have inline reliefs and one has z heads and the other has 195’s. My stock bottom end has 11r’s.

price difference used to be about $500 between the two.

 

Intake valve orientation with a stock piston... nothing more, nothing less...

 

The question is simple. If you have a stock shortblock with very minimal valve relief pistons, is there any reason to use an afr 195 head over an 11R 190. The answer is very simple. There is no reason to pay more for the 195 and then deal with valve to piston issues, when you can have the 190 that is cheaper and has a mile of piston to valve clearance.

Once you change the piston, the original question is moot.

 

If you have a stock shortblock with very minimal valve relief pistons, is there any reason to use an afr 195 head over an 11R 190?

NO!

 

All things equal on a stock 302 shortblock the TW would make more than the AFR due to having the room to run a real cam. The piston to valve clearance would be the limiting factor for the AFR heads in this scenario. A change in pistons or some flycutting and it's most likely a toss up.

 

People used to think that notching stock pistons to clear 2.02 inch intake valves was simple engine building. You could ask a question about notching pistons on any car site and have 10+ people tell you how they did it. Now you can just buy a twisted wedge head and avoid all that.

I would also prefer the stood up valve design of the twisted wedge if you were to go all out and raise the intake port. This wouldn’t just be porting. Would likely involve some welding to top of the ports to add material and filling of the bottom of the ports. Or like the old days when they welded the chamber of the old twisted wedges to lower the valve seats and accomplish the same thing without raising the ports. Max effort stuff.

 

Directly comparing the overall port volume of each of these cylinder heads can be misleading. The twisted wedge has a shorter port than the AFR head. It would be interesting to know the minimum cross-sectional area and the average cross-section of each port.

 

This was mentioned a few years back when someone was comparing TW vs AFR, I believe it was the 11r 205 vs AFR 205. And they mentioned how the 11r has a shorter port and due to that it was more comparable to the AFR 220 rather than the 205.
Then someone else mentioned how it’s preferable to choose a head that flows the most and has a smaller port due to port velocity. For example, if the 11r 205 and the AFR 195 flowed the same amount of air at the same amount of lift then i theory the 195 would out perform the 205 due to port velocity. At least that’s how I understood it, maybe one of the gurus can chime in on this.

 

It is a can of worms that has all the makings of a 3-4 page **** show thread. Just sit and watch it go off the rails shortly. The key in this particular question is the piston in a stock 302 shortblock, nothing else. The 11R has an 11 and 13 degree valve angle and this lends itself to an extreme amount of piston to valve clearance. Just like the old wedge head that was 15 and 17 degree, this is the main reason the old wedge heads were used so much in the 90s' and onward.

Afr and all the other inline heads that are 20 degree valve angles, need more valve relief in the piston and a stock 302 piston has very little valve relief from the get go, so the wedge head is a defacto no brainer for the average fox body guy over the last 30 years.

 

Great info guys. Thanks!

 

The big question is more of convenience or power.

The TW heads are an easy swap for the "average guy" with a stock bottom end. Lots of room for a camshaft, though the "average guy" we're talking about is not looking to set the world on fire and probably wanting something fun to drive.

If that be the case, the AFR 165 and the TW 170 (FAC or 11R) are the ticket.

One other thing that most "average guy" seem to overlook is the "entire induction system" and focus on random flow numbers or other marketing bovine feces. No sense in purchasing a great set of "XXX" heads and bolting on a POS GT40/Exporer intake with a 65mm throttle body and a letter cam. Talk about a mismatched pile!

Now.... when a "not average guy" is looking to keep his stock bottom end but destroy the local Street Outlaw TV sycophant... then we're talking as set of tweaked TW 205-11R or a fully race ported FAC 170 casting. Add in a ported SysteMAX II or maybe the discontinued Victor 5.0 EFI ... a serious roller camshaft, some quality long tubes and a GF101A bolted into good chassis...

 

Now.... when a "not average guy" is looking to keep his stock bottom end but destroy the local Street Outlaw TV sycophant... then we're talking as set of tweaked TW 205-11R or a fully race ported FAC 170 casting. Add in a ported SysteMAX II or maybe the discontinued Victor 5.0 EFI ... a serious roller camshaft, some quality long tubes and a GF101A bolted into good chassis...

I like the sounds of that. I need to get the GT40's into the 11's then step up my stock short block program.

 

The two heads, out of the box have very close flow numbers, wit the 11R's flow slightly exceeding the 195. In a mildly modified 306, it's pretty much a distinction without a difference. So, use whichever one is more convenient.

The caveat is this. What is a basically stock 306 going to do with 308 cfm at .600?

I'd use 165's, ProMAXX, the smaller Eliminator heads. or the little 11Rs. 266 at .500 makes much better sense.