Blown TD 25-30lbs of boost. Currently running Ti intakes and SS exhaust valves. Would it be worth it to switch to Ti exhaust valves? What would be the pluses and minuses? What about Inconal ?

I would go with Inconel for the heat resistance. The weight is not a huge issue on the exhaust.

I wonder what the weight differance is between Ti and Inconel. I know there is a pretty good price differance. Currently running aluminum T&D rockers on the exh so any weight saving would help reliability I would think.

quote:

Originally posted by Big Steve:
I wonder what the weight differance is between Ti and Inconel. I know there is a pretty good price differance. Currently running aluminum T&D rockers on the exh so any weight saving would help reliability I would think.

Gonna say the weight thing is a non issue here, most of the load on the rockers on a blown deal come trying to open the valve to release the cylinder pressure.
I know of a few Promod guys running Tit ex valves, probably the short duration drag stuff keeps the heat at an acceptable level.
Also normally due the valve's back angles, Tit valve flow better than SS valves (tulip shape vs nail head).

If you running a good deal of boost you may want to get those AL rocker out, its a bad day when you break an EX rocker at WOT.

BTW I believe Inconel is very similar to SS weight wise.

Pulled an exhaust rocker stand out of the head twice this year, not fun. It killed the intake lifter both times and an intake adjuster one time.

I would go with inconel exhaust as well

Yea I broke a exh rocker very early on under WOT after I built the motor hydraulicing the cylinder Wasnt the rockers fault just got caught up in a chain of events including broken exh stand, int rocker, 2 push rods and lifter. Also bent the exh valve.
I was suppose to get steel exh rockers but there was some confusion and after waiting almost 3 months from T&D for the set, aluminum rockers showed up so I had little choice but to go with them or wait even longer. If I make the switch I will get Manton steel rockers.

IMO no.PM sent about why.

quote:

Originally posted by Big Steve:
Yea I broke a exh rocker very early on under WOT after I built the motor hydraulicing the cylinder Wasnt the rockers fault just got caught up in a chain of events including broken exh stand, int rocker, 2 push rods and lifter. Also bent the exh valve.
I was suppose to get steel exh rockers but there was some confusion and after waiting almost 3 months from T&D for the set, aluminum rockers showed up so I had little choice but to go with them or wait even longer. If I make the switch I will get Manton steel rockers.

From what little I know about it I would go with the Manton rockers before I would worry about the exhaust valves. Man, they are expensive though.

I ran stainless for awhile. They would leak 100% after about 20 passes with a 2 thread tuneup but it never ran any faster when I replaced. I only replaced because I was afraid of one failing (they got to looking pretty ugly if I kept running them). Eventually switched to inconel and have had good luck. I go 8k maybe 8300 almost every pass.

Also, Crower stainless rockers are worth a look. Great performance and great customer service.

quote:

Originally posted by BJs Wild Ride:
I ran stainless for awhile. They would leak 100% after about 20 passes with a 2 thread tuneup but it never ran any faster when I replaced. I only replaced because I was afraid of one failing (they got to looking pretty ugly if I kept running them). Eventually switched to inconel and have had good luck. I go 8k maybe 8300 almost every pass.

Also, Crower stainless rockers are worth a look. Great performance and great customer service.

Did the leakage go away after switching to Inconel? I have a few leaking pretty good but ran 6.07 @ 228 last full pull and thats after a 6.05 223 that melted a ground strap.

Reason I would look first at the Manton is they are made to fit the T&D stands. JR Baxter is running them, but he has all the cool stuff...

I once had a Trans Am team manager and engine builder use our old shop for machine work and dyno.

He raced a Turbo Porsche.....inline 4 cylinder and ran a ton of boost....

The only material that did not fail for him was Inconel....

He had block deck O-rings made from Inconel...…

He eventually worked for Rousch's turbo Tran Am program and then became Toyota USA NASCAR racings head man.....He knew his stuff !!

Off shore powerboat racing is another very abusive environment.....they use Inconel …

Fun Fact, when Inconel melts it makes little green balls.

Hi Steve, I would use the inconel exhausts and titanium intakes. My son just switched to the Crower stainless shaft rockers. First class piece for a number of reasons.

Bob

quote:

Originally posted by BJs Wild Ride:
I ran stainless for awhile. They would leak 100% after about 20 passes with a 2 thread tuneup but it never ran any faster when I replaced. I only replaced because I was afraid of one failing (they got to looking pretty ugly if I kept running them). Eventually switched to inconel and have had good luck. I go 8k maybe 8300 almost every pass.

Also, Crower stainless rockers are worth a look. Great performance and great customer service.

We aren't talking about a NA bracket motor here,,, leak down tests are static and the motor lives in a dynamic world. Its very common to see large leak numbers and still have the motor run great! Unless something is really hurt, static leakage from valves or rings doesn't seam to make any difference in performance...

Never had leakage issue with ss valve the year we had them in TA/FC.I burnt few pistons,can't find the line till you step over it.LOL

blown application should always have Inconel on the exhaust side!!..but what do I know

quote:

Originally posted by jenavet:
blown application should always have Inconel on the exhaust side!!..but what do I know

How to do wheelies and kill dear!

Poor Deer... At least the name is not John Deer...

nope think hes talking the good kind of deer,kind with tender loin. Was looking for some this morning,they never showed.