SS MPSTR

Again, what's a "fair share" and what differentiates these from yours? Guides wear - that's a fact. How fast they wear and why is what I'm looking for.

Six-Gun-Todd

Cams are typically composed of exceptionally durable steel alloys and heat treated extensively.....we aren't dealing with a flat tapper cam here after all.

As for the lifters....I haven't heard of any roller failures and since the lifters are of the hydraulic variety the added load is offset by oil pressure.

And to be funny.....stock intake valves are heavier then exhaust valves so the system is already at an imbalance. (slight as it may be)

PCMusicGuy

Okay, I have to ask because I just don't know. Are sodium filled, SS, and inconel the only options for exhaust valves? Is titanium not available or a poor choice?

jimman

Sodium filled are Titanium.

jimman

40% increase in weight is serious Sh-- at 7K

jimman

Hell on a lighter note this is a photo of one of the valves that were in Dale Jr's Corvette when he crashed it at Infinion a few years ago. A friend of mine bought the left overs and tore the engine down and sent Dale the parts and he autographed them.

Six-Gun-Todd

True.....but our offshore 1200 hp BBC engines get parked at 7400 rpm for the duration of a boat race (30-40 minutes straight per race) and a 60% differential in weight between titanium intake and inconel exhaust valves show no difference in wear on the components you noted. Granted we run 80-100 lbs more exhaust spring pressure.....but the cam and lifters (solid roller) look identical lobe to lobe.

But honestly....if it let's you sleep more sound at night far be it from a race engine builder to persuade you otherwise

jimman

I'm not talking about 30 minute races or a quarter mile run, I'm talking about a street machine that can go over 100K miles, do you track the data of your end users on the street or are they mostly garage queens. We are talking about reciprocating resonance and what it can do long term. Also with all do respects, I never heard of ya before.

TORQJNKY

with UNREAL

Unreal

Like Gannet said, the exhaust valves are steel. They are a two piece design. A hollow stem that is filled with sodium then friction welded to a solid steel head. They are lighter than solid SS valves because of the sodium/hollow part.

Ti valves are expensive. Intake valves are $125 each, exhaust valves are $35 each (MSRP). If you can find Ti valves for about $85 each so 8 of them are ~$700. Plus Ti valves don't like heat as much. Looks like porsche guys and people who run Ti exhaust valves normally go with high end exotic valve seats (Copper Berylium) to help dissapate heat.

2000FRCZ19

i called trick flow today and they do not have the powedered metal guides. i was told by a supplier that they do but this can now be confirmed that they do not. (more bad internet info) they did give me the number to total engine airflow and i talked to them. they told me they are seeing lots of guide failures in the ls7 as well. he said the guide is an odd size and bronze is the only option at this time. they did state that the powdered metal guide will wear a lot less than the bronze. they told me there was a geometry issue with the ls7 heads. they sugested changing rockers. just a little more info from a machinest to add to the mix of possible problems. i am currious as to how many people have ss valves and bronze guides in their set ups and are going to be trouble free long term. i know there are people running them and they do work but how many miles have they put on them with less wear than stock? i am leaning in this direction with mine.

kirks5oh

interesting discussion. i'm about to upgrade the cam in my car, and have decided to have the heads pulled, and get some work done on them. i'm assuming WCCH is one of the premier shops to get this done at??

i'm not looking for the absolute maximum hp increase (i want driveability), but would like to get them milled a bit. i'm assuming WCCH will give us (myself and my shop/builder) options to upgrade all the necessary components (springs, valves, etc). anything that i need to specify when i talk with the shop as far as upgrading the heads (other than the amount of material i want milled)?? does WCCH need to know the specs of the cam i plan on using??

jimman

Interesting, Gm parts quote MSRP, intake $123 and exhaust $70.00

Unreal

I took my prices from parts taxi. I just ordered 8 2.25" Ti intake valves. $1100. Ti is not cheap.

jimman

heads MSRP $1765 and change each and as you all know, no guides sold separately. I'm getting mine pulled at the end of the month to check clearances. This could get ugly.

Bill Dearborn

My engine failed Tuesday. First there was a little vibration just before I put the clutch in to shift from 3rd to 4th and when I put the clutch in the tach dropped to zero. Coasted to a stop with lots of white smoke all around the car. Coolant was coming out of the exhaust. Just for the hell of it I hit the start button and the engine cranked but made a sort of thumping noise. Later on after getting the car trailered home I hit the start button and it actually fired and ran with a lot of rattling before I could hit the off button. Talked to the Service Writer today and he told me the mechanic had pulled the spark plugs and valve covers. There was nothing he could see wrong from the top of the engine. All valve springs, valves and related hardware were where they should be. When he inspected the cylinders with a bore scope he saw one cylinder wall with a hole in it. They are waiting for instructions from GM now. Most likely will pull the ECM programming and send that to GM and may actually pull the ECM to send to them. They have done both before. He told me sometimes GM asks them to pull the engine and send it back before authorizing replacement but he hopes that doesn't happen since it ties up a lift from the time they send it to GM until they get approval to order a new engine and get it installed.

At this time they have no idea what caused the failure although he doesn't think it was a valve failure.

Bill

ramairws6

My heads were done by Richard at WCCH a month or so ago and believe it or not with less then 3000 miles on them there was excessive exhaust guide wear on all of them! c

AzDave47

Sorry to hear this, Bill. Keep us posted on what they find and how you get treated by GM.

TORQJNKY

What all was done to them? Please list replaced parts and brand if you can.

TORQJNKY

Sorry to hear Bill. I wonder if the exhaust valve head snapped off, leaving the stem in place. That would make it difficult to say by looking at the top of the head because I'd think everything would look normal. Any mods to the car?