bk,

Any progress in finding out what caused the failure ?

Bill K

Motor is getting torn down as we speak. After paying for "port work" on brand new AFR heads, it turns out the exhaust side was never ported but the intake said looks like it was hit with a meat grinder. The valves are not mated properly to the heads, the intake gasket was over hanging the intake ports. The intake that was "ported" didn't line up to the heads. (pics soon to follow). The springs had old gm style spacers in it, the builder says I had 100 psi too much spring pressure, three lobes on the cam are gone in less than 10 hours. The lobes are so bad they have grooves worn in them. The roller tips on the rockers (brand new btw) are worn off. (pics to follow) The stud girdles were on backwards, the builder said he had never seen them on like that before and had to use a pry bar to get them off. The lifters were gen iv type on a gen v block. That means the had the bar between them when they didn't need it. The timing chain was an old no name single roller type. (nice for a 10k 800 hp motor rebuild.....) The thrust bearing was beat to death, builder isn't sure if the that was first to go or if the rounded cam was first. Either way after a valve adjustment this motor was supposedly good to go.:rolleyes: We will have our day in court. I'm having two different builders document the carnage in this motor and then I'll have my attorney serve the papers.

A lesson to all, never drop you motor off in a dirty backyard.
Ask your builder for refrences, real world people with motors similar or better than yours.
Never believe just because someone tells you how good they are, that it's true.
Just because the guy read a few books and can dazzle you with knowledge doesn't mean he can actually do machine work.
Just because the guy freelances for a magazine doesn't mean he knows anything except how to bs his way through a story.



The new parts in this motor look to be about 2500 dollars worth of trash plus 7500 dollars worth of labor. Every part including the block is junk now. The pistons are covered in black soot, new builder says he thinks the cylinders were washed down, front two pistons are melted either from lack of oil or from being washed down. This guy supposedly set up and boost refferenced the carbs. Nice job huh?

I'll have pics and more info Tuesday.

Nothing wrong with your lines. The "THUNK" you wre hearing might not have been a rod. When cam lobes wear down, (I think I am reading you right) they sound like a rod knocking. The cam lobe is slaming on the lifter and generating the noise. If the lash was off, it might have been from the cam. Once this happens, sometimes the pushrods jump out of the rocker arm and get cramed under the lifter. This causes the valve to stay open and the piston head intruduces itself.

I didn't read your whole thread, but this all could have starte with a cam that was not broken in correctly. Poorly orted heads will not blow a motor, and even a poorly installed #10 line is big enough for a oil remote on an engine that runs at less than 6000 rpm's.

Just something I learned about cams last week. I cooked a brand new one too. Made it for 15 minutes on the lake. Had a carb problem that would not let us get cam broke in. I run flat tappet solid lifter type though.

Good luck to you.

Sounds like amateur hour to me. Should have been no reason to even touch a new AFR head. If he bougt the right size, they are perfect. Guys like me save up money to buy heads like that. You port and polish to try to get to heads like that.

Black soot is from running fat. Are pistons melted on top or bottom? When cams flatten it screws up the valve sequence. with a blower it is not using the intake stroke to meter the fuel. If the intake valve was stuck open, the blower kept pushing fuel into the chamber and fattened it up. This could have been the reason your pistons cooked.

I am looking forward to see how this thread turns out because I am always wanting to learn more about these type engines.

Unfortunately, we can only learn from the mistakes. :(

If you more experienced guys find anything wrong with my logic on the last 2 posts, please tell me where it is. I am just thinking out loud here.

Thanks.

Were your afr heads as cast or cnc to start with? If they were cnc be GLAD the so called builder never attacked the exhaust port as the performance will pretty much only go down hill if ground on (everything is sized and perfectly balanced out of the box),Smitty

Oh no, the front two bearings are junk, the crank is blue, three rods are cracked along with the front two pistons melting. We can't find markings on the no name rods yet to figure out what they are. The crank is a middle of the road Scat crank. The new builder said it's not the worst they make but not a 10k rebuild or an 800 to 900 hp crank. That's no surprise though.......

I was thinking about this also. Did your guy check that the oil was flowing through the filter in the proper direction. A lot of inexperienced marine guys will put the cooler lines on backwards and the filter will basically come apart inside the casing.

This kind of oversight will cook an engine in the way you described.

Good luck with your quest.

Heads were complete, brand new, cnc bowl blended 345's. They came with stainless intake and inconel exhaust. First thing the con artist did was remove the valves. He said he couldn't figure out what part numbers they were and he called AFR and they supposedly told him they had never heard of the part numbers before. He also said the valve guide clearances were all wrong and that AFR doesn't put heads together so whoever sold me the heads ripped me off and put cheap valves in them. :rolleyes: But, being that Don at Triad Performance and I are good friends, I got the heads at Don's cost straight from AFR. I knew I was being lied to at that point but I had to wait until I had the valves in my hand to find out for myself. In the end I got the valves back and called AFR with the Ferria part numbers, guess what? They were exactly what the invoice from AFR called for, stainless intake and inconel exhaust valves. :rolleyes:

http://www.tpmarine.com/index.asp?Pa...OD&ProdID=1395

I rigged it myself, checked, double, and triple checked to make sure the hoses were all in the right places. The oil adapter and remote oil filter were brand new billet pieces form cp, they are also plainly marked in and out.


Smitty mentioned swept fitting, there's nothing but swept fittings.

Was the valve job touched,afr uses a very good valve job that enhances the flow of their heads with wide seay margins,as soon as these are cut on it REDUCES the flow signifigantly,I'm going thru this myself. When I bought my AFR's I had a local machine shop assemble them,they told me the valve job "was all screwed up" and cut on the valve job :mad: (I didn't know any better, (this was 2 years ago),now I'm trying to have them straightened out but its not looking too great,the flow is DOWN 30-40 cfm,good luck. Hopefully the rest of this mess can also be fixed so yo can salvage your boating season. I luckily have been building motors for last 24 years so I do my own engine assembly work (except headwork) so I have avoided major engine disasters (I have a hard time trusting ANYONE),Smitty