offshorexcursion

Hey Bob!

Before we derail this thread let me start another thread now that your ready to respond.....this time can you have your lawyer refrain from sending threats to OSO to delete it?

C1000

Now it gets interesting, lets see where this goes?

Black Baja

I would have thought you could have come up with a better response than that.

MER Performance

I don't really, have anything to contribute towards rocker arm geometry. If AFR, machines all their stand pads the same and the valve lengths are the same, I know; a set of Jesel shaft mounted rocker arms will pretty much be consistent with stand height and or offset. In the Sportsman Series, being either a A,B,C stand in offset and adjustable in height.

As far, as AFR Heads coming RACE READY, I guess it's what you are paying for. I have many times ordered AFR Heads, with their spring pack and have switched them out for what I needed; and used those take off springs for something else...So you; exchange springs set your installed heights...

Let's get back to the valve to guide clearance. Just checked a set of AFRs on the shelf, .0015" intake and exhaust. Typically; if I install new guides, for a 11/32 valve, either A NA or Forced Induction its .001-.0012", exhaust .0015-.00152". On a 3/8 valve .0015" intake, .002' exhaust. smaller stem; smaller clearance..... bigger valve, bigger clearance.... The intake valve is continuously, cooled by the intake charge, yep; the exhaust is in the FIRE, seat width and oil on the stem are important, I do not use a positive seal on the exhaust valve and I remove the spiral ring on the teflon seal for exhaust.

Doesn't matter what I use to measure the clearance, either a pointed bore gauge or my Sunnen valve guide bore gauge.These measurements read the same, give a measuring instrument to a inexperienced user and the measurements will not be consistent.

Has anyone ever looked at the guides in the AFRs ? the bore is very smooth.....No Cross Hatch..... the guides are not honed to size...... It takes to long, with many chances for error... Here's what I think; guides are machined with close tolerances and precision.... the guides are chilled, heads are heated at some point, they are dropped in and the guide is in with it's interference fit, guide size is figured in with contraction of aluminum and fit of guide.....These guides are not driven in or they would show signs of this..... If anyone knows; the exact process please share it....

Budman II

Someone asked about that in the comments, and he answered it by saying to add .050 for hyd lifters. Also said to have cam on base circle. I think he should also address the fact that even with proper geometry with mid-lift method as described, you can still end up with the roller too close to the edge of the valve tip, as mentioned earlier in this post. You cannot ignore this aspect of it altogether, or you could end up with a roller tip going over the tip and contacting the retainer. I had a lot of issues with this on my build, until I found a set of rockers that had a shorter tip / trunion distance. Crower actually makes offset trunion rockers to address this issue, but they are pricey!

Black Baja

Mark what do you typically see as far as run out on the valve job?

ICDEDPPL

Pretty sure Kris was being sarcastic.
Please don`t like my post !!! lol

MILD THUNDER

I am somewhat confused here. When you sold heads to my Friend Joe B (and a couple others), that were going on a 1000HP forced induction build, you told him and his lead engine builder, they are just fine out of the box, and spec'd for the application. At no point, was Joe advised, to bring the heads to his machine shop, and have them gone through, on your part. There's at least a dozen oso members, who have been advised , or should I say, not advised, in the same manner when purchasing heads from you. I too was under the IMPRESSION, that you being who you are, had some kind of magical power, to influence AFR, to size guides, and set springs up, per the application ( I know, at one time I believed in Santa Claus as well).

You sat back, watching thread after thread after thread, of your supporters, argue and argue and argue, over whether or not these heads are custom built, "race ready", etc etc. But, now, you chime in, because you happen to have some "defense", in writing? Funny how you keep records of certain things, that may protect you from legal repercussions, and yet, story changes "off the record", on the telephone about everything, but never in writing. Telling guys, " I have THOUSANDS of those heads in the field, and have NEVER saw a valve stick", or how "20w50 is fine for hi rev morels", until a problem arises. Then its "you need 5w40 for those lifters". Now you are here, saying ANY PROPER engine builder, would go thru the heads, before running the engine. Which I totally agree with, although, how many customers were CLEARLY told this????

So, which is it Bob, now that you decided to grace us with your presence when it's convenient for you to "chime in",

Are AFR heads sold by YOU, ready to bolt on a marine application in your honest engine building/developing opinion?

Are AFR heads machined to your specifications, or are they simply ordered with an inconel valve upgrade, and spring choice, like any other AFR dealer, or John doe consumer can order?

Did you advise Joe Brabec that he can purchase two sets of complete CNC ported, AFR 315 heads from you, and they would be ready to go and spec'd for his new 1000HP engine builds, or did you advise him to take him to his machinist for disassembly and checked thoroughly before installation?

mike tkach

ok fellas lets try to keep this thread on track.what i am looking for is oso members that have had an issue with aftermarket cylinder heads of any brand and what the issue was.i also welcome information from people in the industry who install these heads on engine builds.through the years i have used dart and recently several sets of afr heads.my reason for starting this thread was to gain information about aftermarket cylinder heads.

F-2 Speedy

I believe in Santa, he's bringing me Whipples this year