About to cry over my heads

Ranchero5.0

The Voice of Reason
Jan 1, 1999
5,306
0
76
Hagerstown MD
I'm having problems with the shop I use over my dang near new AFR 185's. Lost the head gaskets (detonation under boost) before Christmas and took them out to show him the gaskets. He popped the heads out of the truck and said he'd need to go over them to make sure they didn't get warped etc. When I got home I noticed the exhaust valves had hit the pistons at one time. He pulled them down and found the guides had galled to the valve on the exhaust. I just told him to make it right and get the best gasket he could find less O ring's. Got a bill for $497 (valve job, mill face, hone guides, valve job, new racing seals, and felpro 1021 boss 302 race gaskets etc). Bout flipped, but he said they were 'right' now. Drove it for a few days and it started smoking oily pretty bad. Shop said the seals may have lifted off the head so I sloppily pulled it into the garage and jacked it up to work on. Seals were ok, but the intake valves were loose in the guides and wobbled (never did that before). Next told to pop heads and bring them back in. PITA because it's all studded. Guides are ok I'm told (WTF). Call a race motor builder about the ARP head studs and how many time I can reuse them (thinking maybe they are stretching). He says dang near forever, but the oil problem may be coming from a piston land cracked.

Now I'm a firm believer in 'last thing first' when it comes to machines breaking down as in check the last thing done first because it's probally screwed up...

Out comes the motor (blower pulley to bellhousing) and it get's flipped over on the stand. Without removing the windage tray (PITA) I can get the piston out where the gasket let go (#7). Bearings look like new (new crank 15k ago, same as the heads). Pistons a little scratched up, but otherwise fine for 40k with a blower and a K+N filter. Same for the bore.

Monday I get to take it out to the shop and see if he ordered the guides for the heads yet. I'm pretty sure they overhoned them and that's the whole problem and I think he knows it. He's going to eat the cost and that's the only reason I'm taking the motor apart to apease him. Heck, I had to use some emory paper on the retainer seat when I got them to pull the valves out of the heads so I know they were like new.


Guess my golden horseshoe finally flipped over.

Jamie
 
Ok, after talking to the guys at AFR and Total Seal today I determined that I overheated the top ring on the piston and it lost tension and the race seals on AFR's is a bad idea. The guide wear is about right for a streetstrip motor and I can expect to rebuild the heads every 40-50k. Kind of a bummer.
 
Ranchero5.0 said:
Ok, after talking to the guys at AFR and Total Seal today I determined that I overheated the top ring on the piston and it lost tension and the race seals on AFR's is a bad idea. The guide wear is about right for a streetstrip motor and I can expect to rebuild the heads every 40-50k. Kind of a bummer.
Do you think that it's normal for the valves to touch the pistons?
C R E E P Y...........
 
Only 40K-50K miles on a set of heads before they need a rebuild is reason enough to keep me away from any AFR heads.
 
I think you need to find another shop. you have performance heads they know what the tolerences need to be and are not (or will not) able to do so. as far as you aver heating the motor and making the valve seals come off is :bs: they just didnt install them correctly, or they didnt make enuff clearance for the lift of the cam (shorter retainers or cut the guides down so the valves wont hit seals and brake them ). as far as the guides gaulding the valves that can be from not enuff clearance between valve and guide or seals not leating any oil pass by or dirt inside of guides.
If you had to sand the grooves on the valves to get them off you either ran the motor seriuosly hard or have cheep valves. I would put a set of manley valves in the heads while they are off.
I worked in a motor rebuild shop for 3 years in the head department
 
Didn't really have enough time to go in depth before. Bought the heads around Xmas '02 with a couple hundred miles tops and tore them down for inspection. The retainers put an edge on the valve where they mate (done it on every set of heads I've ever worked on, edels, TW, AFR's, stockers, windsor SR's, you name it. Takes about two twists with some emory paper to clean up. If you don't it reams material off the guide as you pull the valve off..

Heads were very nice and I put them back together with all the original parts (seals, springs, valves etc.) P/V was almost 1/4" on both valves. Ran it at the track in October and ran a 11.78 @ 119, but it wouldn't rev over 5800. Started losing coolant that fall and tore it down over Xmas '03. Popped the head gaskets and blew the seal on the water pump. At least it's honest so I finished porting the lower while the heads were getting checked.

I was cleaning the piston faces and noticed marring in the exhaust valve reliefs on all the pistons. Called the shop and told him to check it out. He called back that the exhaust valves has bronze galled to them and figured that it most likely wasn't getting any oil. Recommended the hard 'race' seals, milling the face .005", a clean up valve job, resetting the spring pressure to 120 on the seat and the 1021 gaskets.

Put it back together motor ran awesome, pulling to 6k easily in third and fourth getting on the interstate. Third spins about 4500 so I had to pedal the throttle to rev it above that. Over a few days notice the motors using oil and blowing blue out the pipes. Pulled the plugs, oiled. Take it to the shop and they think maybe ONE of the seals lifted. ALL the plugs are oiled...

I'm thinking that they overhoned the guides right off the bat so I pretty much flipped when I popped the springs off and the intake valves were sloppy and the exhausts were fine. The reciept showed that they honed both sides and I never saw the play in the valve guides before they worked on it except when new, they were tight 15k miles ago. Finally decided to run the viton seals instead of teflon, umbrella, race seals and put it back together. Oh, I'm also going to pray and keep the boost retard at 2 degree / psi vs 1.25 degrees.

Jamie