Update: fastcar Bent Exhaust Valve

[fastcar]

Friends,

Got a call from Nick at Dezracing this AM.
The leakdown was inconclusive.
The boreoscope showed nicked piston, but no more.
The removed valve cover showed exhaust rocker arm laying at bottom of head.
The valve is bent. He says the valve moves up and down, but only with force, and that it 'snaps' into place, like the stem is bent, getting hung up on guide.

HOW DOES THIS HAPPEN? Obviously it hit the piston, but HOW, WHY? The damn thing only shifts at 6200, it's not like I can spin it way up. And it's stinking got DOHC. I've shifted 460s faster than that...:confused:

Valve float on a low rev DOHC motor? Maybe the valve became 'sticky' from failed lubrication?

Anyway, what do you guys think?

Also, he wanted to replace head with newbie from Ford costing about $1300 assembled. He says he'd hate just fixing the head. He'd be worried something else would break.

True, but I reminded him there were 16 other worries on the other side of the motor, one head would not solve...;)

I'm leaning toward just doing the valve that bent. I do not want to spend $2700 on new stock heads for this car at this time, much less just replace one side for $1300, which would be retarded.

I'm ready for ideas, thanks

fastcar:burnout:

[ctrlraven]

Driver's side aviator head brand new on ebay $500 with free shipping?
http://cgi.ebay.com/ebaymotors/03-04-05-mustang-aviator-cobra-mach1-4-6-dohc-head-new_W0QQcmdZViewItemQQcategory Z33617QQihZ002QQitemZ120286192 183QQrdZ1QQsspagenameZWDVW

[fastcar]

I just got off the phone with Eric at Century Automotive Machine in Waltham.

When I told him how the motor ran fine when I shut it off, then turned it back on and it was missing he laughed and said:

'When the motor stopped the exhaust valve was open. The seat cooled while you were at the appointment and fell out. I've seen it a thousand times not just on those motors, but Toyotas and Dodges. When you started it, the seat got jammed, bent the valve on the piston and the rocker fell off immediately, then the seat popped back into place. Now everything looks normal, but a bent valve and a lost rocker. Now you need an oversized seat. We use a tighter fit than the factory.'

He also said that he won't do the job unless he shaves the head, because 'In 6 months you will be back, with problems if I don't'. He wants to just take enough off to make the surface flat and new. He said the motor uses a metal head gasket, and in his experience, it is vital this be done.

He also uses green loctite when installing seats in the heads. It's good to $450 and in his experience between more interference and the loctite he's obtaining good results.

BTW, he's qouting just around $150-$200 for the labor to do the head which I think is pretty reasonable.

fastcar:burnout:

[fastcar]

Driver's side aviator head brand new on ebay $500 with free shipping?
http://cgi.ebay.com/ebaymotors/03-04-05-mustang-aviator-cobra-mach1-4-6-dohc-head-new_W0QQcmdZViewItemQQcategory Z33617QQihZ002QQitemZ120286192 183QQrdZ1QQsspagenameZWDVW

Really kind of you, thanks man. I would need the passenger side. It was #3 that went, not #7 as I first stated.

fastcar:burnout:

[Zack]

Honestly, with the mileage your car has, it might be smarter to buy a used, low mileage engine.
Repairing one head at 100k miles is silly, not to mention it will be milled down and could potentially cause an inbalance issue due to that side having higher compression.

FYI, to get the drivers side head off, the passenger side valve cover needs to come off as well to access the timing chain sprocket, which will be more money!

Your call!

[CKMustangCobra]

I would just fix the head/valve. Since the intake and all that needs to come off to remove the head and fix it... another 12 or so bolts to remove the other head and have it slightly milled won't be a huge problem.

I trust he is going to inspect everything while he's in there and make sure another one isn't about to go.

Shave both heads .010".... it will clean the surface flat and you'll pick up a few PSI of operating compression which won't be worth anything in the performance world.

Ask him if he suggests new seats, guides, seals on all of them.... see how much that will cost.

If the cost goes over the price of 2 heads bought off eBay or something go that route.

[FordNut]

For the cost of doing the head(s) you could get a good, low mileage Marauder engine and swap engines.

[Zack]

Honestly, with the mileage your car has, it might be smarter to buy a used, low mileage engine.
Repairing one head at 100k miles is silly, not to mention it will be milled down and could potentially cause an inbalance issue due to that side having higher compression.

FYI, to get the drivers side head off, the passenger side valve cover needs to come off as well to access the timing chain sprocket, which will be more money!

Your call!


For the cost of doing the head(s) you could get a good, low mileage Marauder engine and swap engines.

^^^^What these guys said ;)

[hot-rauder]

For the cost of doing the head(s) you could get a good, low mileage Marauder engine and swap engines.


good luck on findinf one in our area... i just had my motor replaced with a used one... took 5 weeks to get a motor and install it. and about 4300 bucks all said and done.

[ImpalaSlayer]

could always have one shipped adam

[hot-rauder]

could always have one shipped adam


shipping costs are through the roof Dave, i used to work in the car parts business, remember? lol

[merc]

For the cost of doing the head(s) you could get a good, low mileage Marauder engine and swap engines.

I have a low mileage Marauder engine for you.

[ImpalaSlayer]

shipping costs are through the roof Dave, i used to work in the car parts business, remember? lol

no because you never got my damn dash you bum lol

[fastcar]

I have a low mileage Marauder engine for you.

PM sent

fastcar:)