Well, I will post the results good or bad...

 

^^^^^^^^^^^^^^^^^^^^We know. I'm just screwing around with Hos.

BTW I think I have given up the 3.0 dream. Why do it if special Tool is getting 400 with a 2.5. So...How to build the nastiest 2.5 on the planet.....oh wait...reality just snuck back in. Okay the nastiest for 10 k.....

 

If you are starting from scratch, and if you "HAVE" to sleeve the block, I would go for a 2.7L 104mm (Chris White) or a 2.8L 106mm. Will be almost free HP/TQ. David Floyd & JWL will both dyno a big bore vs. a stroked 2.8L.

 

(Chris White) <<<<< Is there anyone else? It's really a race between finance and failure. Hopefully the finace will win, in which case Chris has already sent me the numbers. It's the way I want to go, but if I get that close, then I'm only another 1500.00 away from a 3.0. So... I'm putting a good plan together for a 2.5. Heh I can't get away from Chris, becuase the saved money will end up in a set of Leda's. lol

 

Cool, can't wait to see the results..

By the way the Lindsey High Velocity Exhaust cylinder head option is not the "Port and Polish" thing. You can't port the ceramic lining... It's more like a slightly smaller exhaust valve. I'd assume it's the "thumb on the water hose method" with the same flow rate and smaller area (smaller exhaust valve) you can increase the velocity of the gas. Of course if you take this tool far you'll choke the flow all together.... If you read the discription if says... 3% decrease in flow rate (smaller valve) but with a 45% increase in velocity.

 

ehall:

 

Nice to see you develop more products Vitesse! And dyno results from an independant party is perfect! Well done!

 

It's not a smaller valve...it's a smaller port cross-section just below the valve seat. Valve itself flows the same,port flow a tiny bit less,but at much higher velocity,making the scavenging (and exhaust blowback-problem) much better. Next thing to add is an SFR part...

 

Slightly off topic but why aren't there more guys doing 3.0 turbo's based on the 968 engine? I would think that for the cost of a sleeved 2.8 you could almost complete a 3.0 968 turbo.

 

Please show me how ? Unless you've already
got the engine at hand but to do a proper 3L
turbo it'll cost more than the price of a sleeve
block & that is if you do the work yourself

 

“… 3% decrease in flow rate (smaller valve) but with a 45% increase in velocity. “

I have an idea for a 4-valve head then: Block two of the valves.

To take advantage of better scavenging due to higher gas velocity you need a longer column (more mass), probably the whole resonance length. A simulation program such as Engine Analyzer Pro should be able to quantify

For a given resonance (= header + port) length make the thought experiment of changing the pipe diameter from large to small. The large pipe will not contribute as much to scavenging as the smaller pipe, but at some point the small diameter becomes too restrictive for adequate flow.

A simulation program such as Engine Analyzer Pro should be able to quantify/optimize these scenarios.

Laust

 

Actually, I kind of suspect that it's nothing more
than a cut back on the face of the exhaust valve.
What do you think Laust ?

 

No need to block them...the two valves flow more,but they also keep the speed up,due to the smaller area each valve has just before the valve stem.
Nope. Not until the summer,when it will be updated to show more detail than it does today.
Yes...but then you have a peak intake velocity of over 720 ft/s... Peak as it is is somewhere around 400,so you can kill some flow and gain hp all over the range.