IcemanG17

So after Sean's unforunate engine failure from extreme overheating we took it apart......the heads didn't look so good with lots of rust corrosion, and light pitting in some areas

I took them to a machine shop recommended by an excellent local 928 mechanic.... Valley Balancing in Ceres CA.....they found 4 exhaust valves were bent from the overheating & the usual replacement parts....

Picked them up today...STUNNING....take a look

Mike B

Wow...those look like new! I'm guessing they milled a little off the mounting surface?

Ducman82

nothing like the look of fresh 16v heads!

85euro928

What brand are the new valves? I'm asking bc I'm curious about the loss of the recess in the top of the valve.

ECS Tuning

Oh my those look great !!

Drewster67

Wow - nicely done.

IcemanG17

all of the valves are 100% stock.....4 exhaust valves came from 928intl and the others were stock 84 euro.....it is quite nice...it appears the "bent" valves were 1-4 and 5-8...interesting that the outside exhaust valves would be the hottest?

danglerb

Makes me think what a waste it was spending hours with a razor blade trying to remove all the old gasket etc. on my set. Lots of work and they still look a lot more before than after.

terry gt

Looks like the sodium cooled exhaust valves

85euro928

Any idea of the final CR with the shaved heads?

IcemanG17

it was a very light shave.....only one thousandth..... With a standard headgasket and the piston cuts it should be right at 11-1.....for the 5.0L euro....this engine will be ran by a full stand alone system VEMS tuned by Colin.... I am optimistic it will be 340whp-torque

BC

Better mix in some ethanol for that compression ratio. 91 won't cut it with high race track temps. I know you can tune for retard on knock - I am saying try to not knock at all.

danglerb

Sounds very optimistic, is this with stock Euro S parts except for the slight shave on the heads?

Normal for 5.0L Euro is about 290 rwhp isn't it with a good exhaust etc. Given the stock brain can tune AFR and timing to pretty much whatever you want, why the assumption a different brain will result in any gain whatsoever? Its not going to change the air flow through the motor.

BC

The assumption that there is no gain going from an older OEM ecu to a new aftermarket ECU is a fallacy and a false premise. The false premise is that Porsche did everything in their power to eek out as much HP as possible.

This is completely untrue.

Proper timing and proper fueling represent night and day differences on stock engines.

GlenL

I don't think they'd get that pretty with just 0.001" off. And pretty they are.

Controlling knocking is critical on these engines. 91 octane is the best you can get?