Going with AFR185's, but have a Q

[Bill D]

Going with AFR185\'s, but have a Q

After posting the question, "Help Me select Heads", I have decided to go with a set of AFR 185's. But here is my question to those who are more knowlegable than me: Can I mill .018 (3cc chamber volume) off to achieve my desired compression without sacrificing too much flow?

Thanks
Bill D

 

[Ron Earp]

Re: Going with AFR185\'s, but have a Q

Yes. It is done all the time, contact AFR with questions, they are very helpful. 3cc of the combustion chamber size is not going to disrupt flow to an appreciable extent. I suppose you want to get down to 55cc? Check your P/V clearance though to be safe. Mine were cut down to get compression up and my pistons had to be releived, 11.5:1, can't remember how much was cut off when Billy did it.

R

R

 

[Bill D]

Re: Going with AFR185\'s, but have a Q

Thanks Ron.

If I reduce the chamber volume to 55cc, I am close to my desired compression of 11:1

 

[DBLDREW]

Re: Going with AFR185\'s, but have a Q

If I were you I would go with the victor jr heads rather then the AFR 185. There are a few reasons for this. One the victor jr tends to be around $100 cheaper. But the main reason is that you have a much higher hp potential with the Victor jr heads. If you look at the flow figures of both heads they are very similar..

Lift 400 500 600

Victor Jr
Intake 234 268 291
Exhaust 167 189 195

AFR185
Intake 234 267 277
Exhaust 178 185 191

http://www.airflowresearch.com/

http://www.edelbrock.com/automotive/head_flowdata.html (part# 77189)

So you can see that the flow figures are virtually the same with a little advantage going to the Victor jrs. Now the biggest thing to understand is that the AFR comes with full cnc machining while the Victor jr come as bare castings. So that just goes to show you how well designed the Victor jr heads are to be able to slightly out flow a fully cnc machined head. So the out of box hp of both heads are going to basically be the same but the nice thing with the Victor jr heads is if later down the road if you are looking to upgrade your motor and make more hp if you go with the 185 you will not be able to squeeze much more out of them but with the victor jr heads you can always have them cnc machined and then be in the neighborhood of the power potential of the AFR 205s.

 

[Ron McCall]

Re: Going with AFR185\'s, but have a Q

Bill,
Go with the AFRs and mill.008"-.010" off of the deck of the block. By milling the deck,you are losing the entire area of the bore size ,not just the chamber so you gain more compression by cutting less..The less you mill,the better the intake will fit.
Ron

 

[DBLDREW]

Re: Going with AFR185\'s, but have a Q

Why would you recommend the AFRs over the victor jr? I can understand going with the AFR 205s over the Victor jr but it really doesn’t make much since to spend more money to make a few less hp with going with the 185s. I think that people just assume that as long as it’s a AFR you can’t go wrong, and that is true to an extent they do make great heads but I think that because of the MM&FF article last year that Edelbrock kind of got the raw deal. Because they categorized the heads into 3 categories (group 1 street, group 2 street/strip, group 3 race) and the AFRs I believe had the best results in each of the categories. In just comparing AFR vs Edelbrock it was group 1 AFR 165 vs Performer Group 2 was AFR 185 vs Performer RPM, and group 3 was AFR 205 vs Victor jr.

So I think that because the AFR basically won all of the categories that people will just automatically go with AFR. But considering that the price (performance) of the Performer and the performer RPM is basically the same they should of both been in group 1 against the AFR 165. Also because the Victor jr is about $600 less then the 205s and $100 less then the 185s it should have been tested as a group 2 against the 185s. For the group 3 they should of tested the super victor heads or at least the Glidden cnc victor jr would be a better comparison to the AFR205 race head.

 

[Bill D]

Re: Going with AFR185\'s, but have a Q

Milling the block also affects the intake fit at the front and rear of the manifold.

 

[Ron Earp]

Re: Going with AFR185\'s, but have a Q

Bill are you assembling the motor yourself? If so, then you'll need to consider that, but if not, then your competent engine builder will handle that for you, that is, the millings vs. intake fit.

 

[Bill D]

Re: Going with AFR185\'s, but have a Q

I'm assembling the motor but my machinist is taking care of the machining details. All is covered.

BTW - I don't think you can mill the block .010. Wouldn't that put the top ring close to the deck?

 

[Ron McCall]

Re: Going with AFR185\'s, but have a Q

You can ,and I have, milled the deck .010" on a 302.If your top ring is that close to the deck surface,you have far more serious problems.
So,is it the AFRs or the Victor Jr.s?
Just remember,there is such a thing as too much of a good thing (i.e. Flow)

 

[Ron McCall]

Re: Going with AFR185\'s, but have a Q

[ QUOTE ]
Milling the block also affects the intake fit at the front and rear of the manifold.

[/ QUOTE ]
I understand this.But,you don't have to mill the deck as much as the heads to get the same compression increase.(that is what you were after in the 1st place right?)

 

[Bill D]

Re: Going with AFR185\'s, but have a Q

I calculated that if I mill .003 off the block, I end up with .001 deck clearance. I don't want to have the piston above the deck.

With the Victor Jr's milled to 58cc, I should make 10.52:1 compression. It's less than the 11:1 I wanted, but enough to make for a crisp sounding engine.

 

[Neal]

Re: Going with AFR185\'s, but have a Q

Deck the block to bring the pistons to zero. Minor changes are not likely to effect manifold position. As for heads either flow well. Be carefull to match the valve springs to cam lift. Stock Victor Jr heads support more lift. You may need to upgrade springs with the AFRs depending on your cam. 11:1 is pushing the limits for a street engine. Alloy heads help but good gas is getting hard to find. 10.5 or less is a better bet. Physically check the valve clearance! Don't rely on calculations... If you really want the heads to flow have someone clean up the bowls, gasket match them and do a good valve job. I have TEA heads and they are awesome. www.totalengineairflow.com
Sounds like a fun build.

 

[Lynn Larsen]

Re: Going with AFR185\'s, but have a Q

Neal is absolutely right about the valve springs, but I would go even further to say, "Plan on upgrading your springs and the retainers!!" The springs and retainers in my 205s were crap and didn't fit well at all. If I had run them very long, the springs would have walked all over the place and beat the spring seats (merely a pocket cut into the head) all to heck and back because of the ill fitting retainers. AFR makes really great heads, but the springs, retainers, etc. they use are, IMHO, suspect. Also if the cam and geometry work, I would consider putting cup seats under the springs as well.

Regards,
Lynn

 

[Jim Rosenthal]

Re: Going with AFR185\'s, but have a Q

I used AFR 185s, but bought bare castings and had them assembled with spring, valve and retainer upgrades- also some additional machining. They are great. Mine were done by Flowtech in Rhode Island and I recommend them highly.