problem with aftermarket cylinder heads.
 

i see a lot of talk about aftermarket cylinder head problems out of the box.if you have had issues with any brand id like to hear about your ordeal.i am only looking for actual issues,not what someone said needs to be done,just issues that YOU have had.full force tim,we know your story so no need for you to reply.

When RHS bought out ProAction, the rocker studs where not in proper location. That bit the industry bad. Good news out of all of that was a few bigger cyl heads shops where enlisted to help Comp Cams (who then owned RHS) get the castings squared away.

Following.


Be also nice to hear what the combo is. In otherwords, are we talking 500hp engine, or 1000+hp engine with out of the box heads, sucess or issues. Cold water temps or thermostats involved.

That was also an issue on afr heads. According to tony mamo they corrected it after a certain date.

http://speedtalk.com/forum/viewtopic...=9025&start=15

..

I think the issue was more of a factor of the longer valve causing the contact pattern to be too far on the exhaust side, so they had to relocate the stud location. I was still having a problem with this, but switching to a different rocker corrected the issue. there is another thread that discusses differences in rocker arms.

When I had my Edelbrocks off we checked one valve seat and it was .009 out of round, which in theory would cause the valve to walk and hunt compromising longevity, but no failure as of yet. So I'm curious about your question as well. We know that production heads have less than optimal machine work, but does it really amount to a hill of beans?

For marine stuff the biggest issue is guide clearance. I've seen some pretty out of round and crooked guides as well. Seat run out and depth variations are another thing I check for. Then of course rocker geometry and yes, with more installed height for larger lift cams you can get into a situation where the tip of the rocker starts moving outward. One thing I don't appreciate about AFR heads is they use one valve length for every big block head and many times you don't need near all that installed height. The long valves just exacerbate the geometry issues. I will also say there are a lot of variations in fulcrum lengths with rockers and it's why I always use Crane Golds for aluminum stud mount rockers. They have the right fulcrum length and show the least amount of problems with the longer valves. Push rod clearance can also be an issue with some heads, especially if you want to go to 7/16 push rods.

I saw a significant difference in tip patterns when trying 3 different brand rockers, and optimal pushrod length. For those who simply roll the engine over and look for a pattern on center of stem, and dont care how wide the pattern is, as long as its "centered" , may not ever notice a difference.

Out of a comp steel rocker, scorpion alum rocker, and crane gold, the crane had the best pattern, and closest to center of stem than the other two, on the same valve. This was on dart heads with longer intake valve.

I know some here won't be able to get past the name but for those without an agenda, this might be helpful:

https://www.youtube.com/watch?v=o5is...ature=youtu.be

You need to drop the word agenda.

When you had all the troubles in the Cobra Kit car world and you where speaking out, did you have an agenda ?

What did you think of the video?

Not bad but I did not watch hole thing. First 30 seconds, or thereabouts. Maybe watch whole thing later.

One question for you about your video. You mention determining final length of the pushrod, but I did not see any mention of adding length for proper lifter preload on a hydraulic lifter. Correct me if I am wrong, but wouldn't you want to add the recommended plunger depth to the final determined length of the pushrod?

You are absolutely correct. There were a couple of oversights in the video and that was one of them. The other was to mention that the lifter needs to be on the base circle of the cam. Since all we sell are Morel lifters, we recommend to our customers adding .050", then rounding up to the next nominal pusrod length. Morel recommends 3/4 to a full turn of preload on their lifters. If you're running less preload than that then you need to adjust what you add accordingly. Thanks for mentioning that.

Don't forget to check everything once you put the valve spring back on. Don't know if that was in the video. i couldn't bring myself to watch the whole thing.

My problem was being sold a complete set of heads that were misrepresented as ready to bolt on, resulting in wasted time and money. Luckily the rest of the group of friends and professionals helping me, recommended I have them taken apart and setup correctly for my application before they caused a serious problem.

So I shipped them back out to have them disassembled checking and correcting all the guide clearances for a marine build. Mine needed to be opened up as they were to tight. Also checked valve seat run-out and valve depth, and of coarse milling the heads to get the compression we wanted. We also flowed the heads for the custom cam selection. Then they were reassembled with new springs specific to my cam and installed at the proper height. They also mocked up the shaft rockers to get the rocker geometry correct.

750hp 572 n/a AFR 335 CNC

Didn't you get your heads from Bob Madera? That seems weird that they were not set up correctly for a marine engine.

Yes he did, that was a whole different thread.

Chris,
You are correct, the heads in the collateral valvetrain components were purchased from me. As you can see on the email correspondence from Scott Stinebring the AFR heads would be shipped directly to him complete. That decision was made to purchase them complete because there is very little cost reduction in deleting the spring pack, therefore he was going to repurpose them for a future build. In the line below that you can see “associated valvetrain to upgrade heads for application”. I put together a valve spring package was based on the mass of the valvetrain, rpm level desired, and cam design.

Scott Stinebring would then be required to disassemble the heads, as any proper engine builder would do, measure guide clearances, and any other dimensional measurements he would feel necessary as the lead engine builder, and then provide that information to Kevin. The heads would then be reassembled to the upgraded spec for the engine. This, and multiple other aspects of the engine build were carefully coordinated. As you can see by the second email to Kevin that everyone involved in the processed was apprised of all this information real-time.

I think this makes it quite obvious that the heads were not intended to be “race ready” as delivered out of the box.

Bob

Hey Bob! :D

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?

Now it gets interesting, lets see where this goes?

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

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....

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!

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

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

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?

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.

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

once you go screw blower you will never go back,lol.

Nevermind. I see they are ready to run as delivered.

http://www.offshoreonly.com/forums/d...ml#post4231501

Or maybe they are not.

Sure you are speaking of seat run out ? I'm having a problem with a answer.... I use a Sunnen VGS 20.. I try to use, carbide pilots, which help in deflection... I always check them for straightness, cutter speed and pressure affect your seat run out, worn pilots and tool holders contribute to run out...I always, use marking dye on my seats, with a very fine lapping compound to check seats.

Seat run out, is important, during the machining process.... the problem arises when the valve to guide clearance widens and the valve starts walking all over the valve seat, the intake valve is larger so the more clearance , the more it will deflect and increase seat run out. So, now you just defeated the purpose of a good valve job... .002-.0025 on a 11/32 valve is excessive. That leads to a nice "coat Hanger " affect on valve stem especially on the intake, that will lead to a broken valve....If the guide is straight, and concentric, no reason to make it bigger, intake cooled and lubed with fuel, the exhaust is .0005' larger, in clearance for heat, take the oil away your done... When you run methanol as fuel, we add a top end lube, helps valves and prevents corrosion in fuel system , most guys still may run racing gas for warm up or flushing system after use...

My equipment is only used for my builds, I do not like or do send out the door machine work... one reason, is I have enough to do for myself. I bought my equipment so I had full control of my machine work without headaches..

Yes that's what I meant. Sorry driving up I95. We always Put Marvel Mystery oil the Alcohol.

Back years ago, I ran into a issue with some Dart Heads, that had inferior valve guides... Dart stopped using CHE, for guides and got some SH;;t soft material... these were heads with Jesel shaft rockers, the guides went to so wide of a clearance it was like for a 3/8 valve, bronze material in oil, had a cylinder head that worked for one of the teams in Charlotte, have the guide tested for hardness, needless to say it did meet spec material... All new guides, back together, never a issue again... Be rest assured, that guide was removed from Darts production, this was like 2005-2006

thanks mark,that is the kind of information i am looking for.

Mike, I had to think about it, and that came to mind.... Long time ago, bad memory !!!!!

I just don't have issues with cylinder heads, that was the only time I had a manufacture have a issue.

Oh, here you go, had a Profiler Cylinder head have casting flaw, that leaked water, porosity in it. Early years 2004. Had also a Profiler after a new CNC program was done, 3 holes on exhaust bolt holes went into water jacket.... The guy; doing the cnc machining, I called him he shorted the depth of the hole, no big deal, it comes with the job...this was only because they went to a guy in NC that knows his cylinder heads and it was a oversight, in new program, which I know him and he corrected the program ASAP...
I like AFRs for the money and the product. I have used many Profiler , 12 degree, and the CNC Sniper versions, they cost more and were designed by Darren Morgan, as AFRs by Tony Mammo. I haven't used any Brodix, so I can't comment...

I think the bottom line here is that any experienced, professional engine BUILDER, especially in the marine industry, would never assume any set of production heads, from any manufacturer, would be ready to bolt on a marine engine. If a parts-seller sells a part and describes it as "ready to run", and makes his profit on it, then IMO HE is responsible for that part being as described. If it's not, then it's between him and whoever made and shipped the part. This part is not being advertised as a "production, shelf stocking" AFR head, it's being advertised as a special purpose, ready to run marine-specific head and that's what the engine builder should have CONFIDENCE that he's receiving, and is bolting on. If you buy a set of marine specific heads form me, I will GUARANTEE that's what you're getting and while, if you want to dis-assemble them and inspect them if you want, you don't have to because that's what you ordered and that's what you paid for. If the heads should need further work after being received, then that should be clearly disclosed in any agreement between the parts-seller and the end user, be it a retail customer or machine shop/engine builder.

horsepower1,pardon me for not knowing who you are .you stated [if you buy heads from me].please tell me who you are and what buisness name you use so i know who to call for your [race ready marine heads].