wasn't relevant to what I was posting about.

Gee, let me see, after his first post, the only people that posted were his "buddies". All he seemed to be able to do was hit the like button on their posts. If any of them ever bought anything from Bob, they didn't say so. So their opinions are hearsay at best.

If you have a problem with how OSO runs their site, tell them, not me. We all know who the mods and Admins here are, so ask them.

The way I read the rules on this site, (and most others) the owners of the site make the rules and can do as they see fit. we don't own it, they do. They allow us to play here, but its their playground.

Maybe we should all just let the mods do their job and just stick with the topics.
Had any problems with after market cylinder heads? I think that's what the OP was asking about.

The post you quoted wasn't answering anything you said. Doesn't even mention you.

I answered his question before. no problems. AFR's 50 hrs bolted on out of the box. have run flawless to 6000.

I seem to be learning more about ego's and less about cylinder head as this thread go's down hill.
Ed

https://www.youtube.com/watch?v=1sONfxPCTU0

Same cr ap different day. Only good thing is I have 2 new heros Zone and SB. Never thought MikeT was a bad guy just don't care for some of his friends.

dan,i am not chasing anyone away,foxwell struck me wrong and said i am trying to discredit him,hell until today i never heard of him.

Honest questions to help this thread get back on track

What's an issue?
In my case we found the issue per AFR own recommendation before installing.

How many hours of run time before refresh is considered satisfactory?
IMO only having 50 or 80 hrs is not a guarantee that an "issue" still may not arise. A tight guide might take a while for the premature wear to become "an issue"

If someone had a failure how confident are we that it was or was not due to the head, the parts installed in the head, or the installer? It's hard to pin point the exact cause unless of coarse an engine builder needs to blame a "part failure" to cover thier reputation.

It could be a great thread to gather info even if we don't all agree. Just need to find some more members willing to post but they are all scared of getting bashed.

i have learned quite a bit since i started this thread,one of those things is that not one person has made a claim that any aftermarket cylinder head has had issues.do i do business with bob,yes i do,imo he is a very smart man and his prices are very fair and inline.i will tell you one more time ,i started this thread to gain information about aftermarket cylinder heads,good or bad.if that is a bad agenda,SO BE IT.

How would a tight guide be more of an issue after 50-80 hours?

I'm wondering the same thing. I thought it would clearance itself but I guess we might learn something.

After 80 hours wouldnt a tight guide be self clearancing?

after 80 hrs if something fails it will not be due to a tight guide,although it might be blamed for some other issue.

there are a lot more heads out there than afr...what about the budget stuff? some info to keep the inexperienced new guys out of trouble that might be looking at procomps, edelbrocks etc....

exactly the type of information i am looking for.i have heard all kind of war stories about pro comp heads but no one has posted anything on this thread.i had an edelbrock head stick a exhaust valve within one minute of initial startup,that was on a 95 inch kit for a twin cam harley.i sent it back and they never gave an explination on the failure,they just sent me a different head,app 5000 hard miles later it still runs great.

Its geting to be noobie " I have a merc 454 and want to get more out of it" season. Then he hears "your heads suck" so he heads to ebay...

There's more to valve guide clearance, than whether or not it sticks a valve, or it doesnt. So, if it hasn't stuck a valve at 80 hours, its good right?

What if it was a car? My GPS Chartplotter on my boat, logs miles, avg speed, etc. My average speed, is somewhere in the 30's. This obviously includes idle time, etc. So, lets just say, 80 hours, times say 35 miles per hour. Thats 2,800 miles in the car world. Would you guys call your heads a "Success", if you bolted them on your car, and at 2,800 miles, the valves didn't seize? What if the guides were worn to chit, at 3500 miles? Would you consider that good or bad?

I can probably link up 20-30 threads in about a 5 minute search, of guys complaining about prematurely worn guides, in car forums, with aftermarket heads. I'd be willing to bet, 75% or more of them, bolted them on out of the jegs catalog, or had poor valvetrain geometry. .

Valve guides transfer heat from the valve, control oil seepage to the combustion chamber, control valve to seat contact pattern, control air leaks from manifold vacuum, and must simply be setup, to go the distance. Different guide materials, different stem/guide sizes, coolant temperatures, combustion temperatures, and other things can dictate, what the ideal clearance may be. A head that's meant to go on a 500HP car engine with a 195* thermostat, may require a different stem clearance, than a engine that runs 90* coolant temps, and making in excess of 1000HP. If NONE of that mattered, I would think AFR, would simply erase

Our typical valve guide clearances are .0013”-.0016”. In some severe applications (nitrous, marine endurance racing, or blower usage) looser guides might be required. Check with your engine builder.

Or from Dart

Valve to valve guide clearance is finished at .0012” - .002” with our valves(OD .3415”). If you have a particular clearance for your valves or application the guides should be measured and sized to your specifications.

Just a thought, Is the head at fault or ones diligence on preparing the head for intended service? Today most head porters will choose a brand solely on the casting giving them the material so they can get their port shape and design without welding. So I guess my point would be after you have done your homework and selected a head that is going to give you the best performance for your engine, maybe you should take the time to blueprint the head, check clearances spring heights, pressures, valves. Just like we all do for rod and main bearings. All the engine builders I am familiar with want to do their own valve jobs, spring set up and final guide honing anyway. If your buying a run out of the box head, then that should be part of your homework making sure it is done with all your specs. Just don't assume they will give you what you need.

Agreed! It's one thing to take apart and check for yourself, if in doubt. When the MANUFACTURER even recommends doing so, its even clearer!

If you were buying a short block, and the piston to wall clearance was spec'd for an automotive application, and in your opinion, too tight for marine, would you just run it anyway?

We are talking engines here that are at the risk of thousands, to tens of thousands of dollars in collateral damage, if something goes wrong with a valve seizing, or something else in the cylinder head, and it is literally, peanuts in cost, to have a machine shop dissassemble the heads, check them out, and put back together. I really don't see what the argument is, for ignoring all that, and just bolting them on, and hoping for the best.

Full force Tim was accidently sent solid roller springs on his heads, that had something like 750 lbs of spring pressure. How many do it yourselfer's , get heads shipped to their door, and are actually checking the spring pressure, to even verify the proper springs were installed? Let alone valve guide clearance.

Recieving heads with incorrect valve springs installed, right there, is reason enough for me not to bolt on an out of the box head. Period.

There is an easy solution to this and why some head manufacturers don't do it, I don't understand.

Many heads I have gotten will have a tag wired to a spring (just one per head) with hand written notes on spring lbs at seat and lbs at a certain 'open' measurement.

For the bolt on and goer's that could save many headaches of making sure you got the right heads anyway.

Mistakes happen, and they happen more the busier a place or person is...and in our world that is mid to late spring. Land of the back orders I call it. 75% of the performance world (cars, boats, all the different car racing, trucks, etc,etc) wants there schit somewhere between March and April. Boom ! The sleeping giant (performance public) awakens.

My experience with Pro Comps, came on my old engines.....I had to have them fixed in order to be confident in them... What Gellner had to do...

Valve job due to horrible sealing
New guides and fixed geometry issues to center the valves
new guides and honed guides to .0020/.0022 (does all marine that way)
fix half the Intake and exhaust bolt threads with inserts (crap aluminum)
Replace the very cheap Chinese no name valves with Manley stainless intake and inconel exhaust valves.
Replace the retainer and keepers with comp cams parts
Replace the rocker studs with arp studs.

I know I was not supposed to contribute to this thread as everyone knows my story, but maybe not and maybe once in a while I just might have useful information and experiences that might make people realize I am NOT just some hack garage grease monkey and have actually had many success story's... Mike you know that just from the conversations we had last winter.

Anyway I would based on that info steer clear away from any kind of off brand head just for the quality of aluminum alone... I will say those old engines made some real nice power with pro comps though, I believe they are based off the dart.

Lesson learned, only trust the heads handed to you from the person you trust to go over them/build them.

tim,when i said no need for you to respond it was because your deal is well known.in no way was it meant in a degrading way.your info on the pro comps is the type of thing i want to know about.

joe,i get what you are saying.you and i are usually on the same page but what i see happening is everyone getting nervous that the guides in their heads are incorrectly sized or have other issues that may cause a failure.that was the reason i started this thread,to see how many people have had issues with an aftermarket head.i can,t imagine how many out of the box heads from the major head makers are being run in marine engines today.the thread has taken it,s own life but i am not seeing people reporting issues.we all know that things can go wrong but i just don,t see that every head is wrong,maybe i am just stupid and i sure don,t know everything but it,s hard to argue with success.but what do i know,i,m just a backyard hack.

All good bud, I guess maybe I took it wrong... glad I can help.

What I take out of all this at this point is, in many cases guys bolted them on and have had no issues or we do not know, now at the same time every person that took "bolt on" heads apart found issues that needed address also, so maybe it's more about makin them the best they can be? or taking the chances of failure to absolute minimal? in my opinion after my issues I will never bolt on heads to a marine engine again, and many guys will not either especially after this and my own threads. Now I may have had a bad experience, but you and everyone else cannot argue if nothing else it makes you check things a little further....

There are not many members posting problems but there also are not many members posting positive results, especially in high horsepower extended offshore use.

There is however multiple members explaining what they do to PREVENT problems.

well to equal a boat,,you better be pulling a 10000lb trailer up a hill,,then report back to me.just trying to level the playing feel for us boat guys.

The valve seats in my Darts were bad out of the box. My head builder said Darts seats are some of the worse he sees, but he touches up all new heads no matter what brand.

That's all I got. You guys can get back to bickering...

:food-smiley-007::popcorn:

most people when it,s right they say nothing but when it,s wrong they tell the world.are they preventing a problem,who is to say it was a problem?do you get my drift?

:food-smiley-007::food-smiley-007::food-smiley-007::food-smiley-007::food-smiley-007:im in.

So what's a common run-out on valve seats on a box set of heads? As I said, my Edelbrocks had .009 out of round on just the one that we checked, but I'm curious to what others find.

We bought (4) AFR 325 heads about 6 years ago for a pair of 572 builds that after 30 hours had running issues on the starboard engine. Bleed down's were great on 3 of the 4 engine banks but 1 head showed high bleed #'s. We tore that engine down and found that all 4 exhaust seats were loose and had worked their way up into the head. We shipped all the heads back to AFR for new seats and their full CNC program with a final message from Tony Mamo. Those heads have been great since. We never did find out why the exhaust seats on the 1 head had issues and the other 3 did not but I do not think a teardown when new would have caught the seat problem unless they fell out when the valves were removed. We currently have 4 new AFR heads slated for builds that will be taken apart and checked before installing because of recent threads.

Okay, here are several stand outs - not all of them manufacturer faults:

Pair of Brodix heads. One head had 2 cylinders hand finished combustion chambers, and some port work. Other 2 cyl pairing did not. Heads where ordered as cast.

Canfield BBC screw in casting plugs leaked. Wheren't reusable when takin out. Same heads had springs I wasn't comfortable with when I tested them.
This is quite normal, but worth mentioning for those who want to bolt on and go, some of the pushrods rubbed hard against the head, so those had to be ground a litttle larger.

Brand New Factory small block chevy cast iron head had no spark plug holes drilled and tapped. This was on a brand new GM Longblock. I picked it up at a local GM dealer / GMPP dealer, so this was not an imposter GM crate engine. Doh !

Bowtie small block head leaked water. Indy cylinder head leaked water.

$6000 set of small block Chevy Bowtie aluminum heads came in UPS in beat up box. Rocker studs/valve springs where facing deck surface of other head, with no protection in between. The 1 heads deck/comb chambers where f*ked up bad ! UPS denied claim. Head porter denied issues as he said they where shipped in seperate boxes, but both put into one bigger box. These where not in separate boxes. Total schit show - one off heads you could not just order another set and have that week. Took about 2 yrs, but UPS finally found out (or maybe just gave in ?) that they opened box to make sure these $6000 insured box had $6000 worth of stuff in them and when they looked up part #;s of heads, they found out they where approx $800. Not knowing about custom ported/set up cylinder heads they flagged these, as they thought someone was pulling a fast one. They delivered them late, but with a reduced insurance amt. And again, all f*ked up. So much for racing that year !

I was taught the industry standard is .001" per 1.0" of valve diameter.

"In an effort to reduce manufacturing costs on ready-to-bolt-on heads, "finished" seat rings may be installed in the heads by pressing or driving. This procedure causes the seats to go out-of-round. We have seen them out-of-round 0.014" to 0.016". The limit should be 0.002" or less."

Is anything in a production line really ready to just 'bolt on' ?
Can I buy a 'production' short block not check anything bolt my stuff up and go and have a trouble free summer? If so please send me the info I`m ready to buy.

I don't think your theory applies in the high perofrmance offshore world.

People love to brag about their toys. Powerboat owners especially like to impress. Exaggerating how many hours they run in a season, how fast thier boat goes, how long they can get a bravo drive to last, etc. But in reality they are anchored at the sand bar, lost a race to a slower boat then their claimed top speed, all while having the bravo blues. Why would the same not apply to engines?

There's plenty of proof to say that there is a problem, I think the more accurate question is, how much reliability and piece of mind will I gain for the money?

Sure some can bolt on heads without precision setup. Not everyone needs shaft rockers or piston oilers either. But when it comes to Marine High Performance Engines what's the best bang for the buck while trying to achieve ones goals?

IMO spending a few hundred on double checking and setting up heads is priceless compared to other "upgrades" that may be recommended.

To add in agreement: preventative procedures are derived from not having done them in the past and seeing the results. Knowledgeable marine engine builders are not "assuming" there might be a problem, they know there will be from past experience. Maybe not even their own, but over many years and many experiences form others, we learn what to expect and anticipate. No different than any other "school". I don't have to throw a rock at a window to know it will probably break it. Some windows are thicker, some rocks are heavier, some people throw harder...but in the end you know that if you don't want the window to break, you KNOW you probably shouldn't throw a rock at it. That's why we do this preventative, preemptive work on these engines. I like to tell customers that they will need 2000hp worth of parts for a 1000hp marine build. Not literally, but you get the message. ;)