Time to go Stage II!

[norbs]

Your only running 180 psi on the seat with your heads Donnie?

 

[Alky V6]

Running my fingers in these ports is giving me chills. Oooooh baby. Can't wait to feel those Ti valves in my hand.

 

[Alky V6]

Your only running 180 psi on the seat with your heads Donnie?

The pressures start out at 210 and stabilize to 180-190 after a little time. It takes a long time after that before I start seeing them drop any lower.
You can see in the logs where I started to see 170 on the seat. Those springs had been on the engine since v2.0 was put together. 2004-2005, I believe.
Those springs saw 7400-7800+ rpm on a regular basis.

 

[BlownV6]

Mike (BlownV6). Here are the numbers on the heads I plan to use. I was mistaken about this particular set being new. It is a used set. Bronze guides. Copper seats. Beautiful port work.
Intake port volume: 245cc
CC volume: 45cc

On the rocker pads, both heads;
prog/1810
FE/01/90

On the center exhaust port flange areas, both heads;
000
9018R

The heads Im about to put together for mine are prog #1820 , sept 7 94. That is the latest prog # and date I believe that I have ever seen myself. The ones you have are also very late models and should really be a good set.
Im not going to debate this with you , but as far as valve springs go you are going to need to make a HUGE leep in spring pressure if you want to turn any more rpm or add any more boost. Mike

 

[norbs]

I would be thinking something like 300 lbs seat psi at least? If Donnie know the mass of the components I think he could calculate the psi he needs with his program.

 

[Alky V6]

Im not going to debate this with you , but as far as valve springs go you are going to need to make a HUGE leep in spring pressure if you want to turn any more rpm or add any more boost. Mike

Yes, you are absolutely right about that. The spring pressures I am now using on the Stage I motor are getting me by, right up to 7800 rpm and 30 or so psi boost. The Stage I valves are smaller and lighter than what the Stage II valves are going to be, longer heavier pushrods, heavier valve springs and retainers. Not to mention pushing close to 1,000 to 1,200 more rpm and maybe 10 psi more boost. You're not going to get an argument out of me on that subject.

 

[Alky V6]

I would be thinking something like 300 lbs seat psi at least? If Donnie know the mass of the components I think he could calculate the psi he needs with his program.

Yes, you're right about that. The program can do that for me. In fact, the program has shown me with the springs I'm presently using on the Stage I motor, the valves (exh first) begin to float after 7800 rpm and 30 psi boost.
I will also listen very carefully to the recommendations of the cam supplier.

 

[Alky V6]

I've been playing around with the sim to get some idea of what sort of spring pressures I'm looking at needing for 9,000 rpm and 40 psi boost. Holy cow.
Are people still using rev kits these days, or is it all being handled by the valve springs? Have valve springs evolved that much?

 

[BlownV6]

I've been playing around with the sim to get some idea of what sort of spring pressures I'm looking at needing for 9,000 rpm and 40 psi boost. Holy cow.
Are people still using rev kits these days, or is it all being handled by the valve springs? Have valve springs evolved that much?

Im using 450# on the seat with Manly springs. I can fix you up with what you will need. Intrested to see if the sim says Im in the ball park. BTW Im over 65# of boost. Mike

 

[turbobitt]

I've been playing around with the sim to get some idea of what sort of spring pressures I'm looking at needing for 9,000 rpm and 40 psi boost. Holy cow.
Are people still using rev kits these days, or is it all being handled by the valve springs? Have valve springs evolved that much?

I been told by someone that had some experience with spintron testing that the mass on that side of the rocker doesn't make that much difference and really is no benifit to a rev kit.
Without knowing how aggressive your ramp profiles are/will be, I would be willing to bet you will need 270+ at the seat.

Allan G.

 

[BlownV6]

I been told by someone that had some experience with spintron testing that the mass on that side of the rocker doesn't make that much difference and really is no benifit to a rev kit.
Without knowing how aggressive your ramp profiles are/will be, I would be willing to bet you will need 270+ at the seat.

Allan G.

Those numbers would be close if NA, but when you add the boost to it jumps up. When you add methanol to it it jumps again. Just sayin!! Mike

 

[turbobitt]

Those numbers would be close if NA, but when you add the boost to it jumps up. When you add methanol to it it jumps again. Just sayin!! Mike

Not really, in a turbo application and low back pressure, it is pressure ballanced with repect to the valve train like a NA application. Blower applications are really pressure biased on the intake and with 65# boost would require a significant spring.

Allan G.

 

[Alky V6]

Keep in mind, I do not have accurate weights for the valvetrain components yet. Good guesses, though.
I'm up to 500 on the seat and a 1,000 lbs/in spring rate. The sim will not allow any higher. That is the limit of the sim. This is giving me no float at 9,000 rpm, but float of only the exh, starting in at 9,250. The combo is showing potential all the way to 9,750, with hp peaking at 8750 rpm. I'd like to at least make the redline somewhere between 9250 and 9500 rpm.
I'm up to 6.69 hp/cu in with the 3.06 stroke crank. Boost ramping in and peaking at 41.4 psi @ 9000 rpm.
Exhaust back pressure to boost still showing better than 1:1.
The torque curve is amazingly flat from 6750-8750 rpm. The sim is not very good at simulating what the spool up characteristics are actually going to be like, so the torque curve may not plateau as early as 6750 rpm.
The boost ramp up through the rpm band is such that it is causing my self imposed BMEP limit to be skirted all the way up the rpm band, right up to peak hp at 8750 rpm.
The exhaust side header specs, needed to come up with this power curve, look very reasonable in relation to the size step up from the Stage I headers. I'm going to go ahead and use these specs.
I'm going to continue tinkering with the cam specs a little. So far, I've been using a 'mild solid roller ramp' as defined by the sim.
I'm very excited. I didn't expect to see this high of a hp level with the short stroke crank.

 

[Alky V6]

It was not easy coming up with this power curve.

 

[Dusty Bradford]

I'm very excited. I didn't expect to see this high of a hp level with the short stroke crank.

Why so? When you look at what stroke does, the stroke only changes the rpm needed to make the hp.

3.06 or 3.625 will make the same hp but the rpm needed to achieve it is different. A stroker motor can operate at a lower rpm which increases reliability.

 

[turbobitt]

Keep in mind, I do not have accurate weights for the valvetrain components yet. Good guesses, though.
I'm up to 500 on the seat and a 1,000 lbs/in spring rate. The sim will not allow any higher. That is the limit of the sim. This is giving me no float at 9,000 rpm, but float of only the exh, starting in at 9,250. The combo is showing potential all the way to 9,750, with hp peaking at 8750 rpm. I'd like to at least make the redline somewhere between 9250 and 9500 rpm.
I'm up to 6.69 hp/cu in with the 3.06 stroke crank. Boost ramping in and peaking at 41.4 psi @ 9000 rpm.
Exhaust back pressure to boost still showing better than 1:1.
The torque curve is amazingly flat from 6750-8750 rpm. The sim is not very good at simulating what the spool up characteristics are actually going to be like, so the torque curve may not plateau as early as 6750 rpm.
The boost ramp up through the rpm band is such that it is causing my self imposed BMEP limit to be skirted all the way up the rpm band, right up to peak hp at 8750 rpm.
The exhaust side header specs needed to come up with this power curve look very reasonable in relation to the size step up from the Stage I headers. I'm going to go ahead and use these specs.
I'm going to continue tinkering with the cam specs a little. So far, I've been using a 'mild solid roller ramp' as defined by the sim.
I'm very excited. I didn't expect to see this high of a hp level with the short stroke crank.

What kind of primary tube dia are you loooking at ?

 

[Alky V6]

Why so? When you look at what stroke does, the stroke only changes the rpm needed to make the hp.

3.06 or 3.625 will make the same hp but the rpm needed to achieve it is different. A stroker motor can operate at a lower rpm which increases reliability.

I'm just saying, I was pleasantly surprised by the time I had finished with the sim, last night. I started out the night with the output being in the 1200s.

 

[Alky V6]

What kind of primary tube dia are you loooking at ?

I'm going to keep the exact specs of the exhaust and cam to myself. Besides, I'm sure the specs are too crazy to be acceptable to anyone anyway. If the project turns out well, I'll release the specs.
I will say the primaries are stepped. The specs of the exhaust header system probably made the largest difference, and was surprisingly touchy.

 

[Alky V6]

Just as a comparison. A 276 cid V6 with a 6.69 hp/cid output would be putting out 1,846.4 bhp. Assuming a comparable boost level.

 

[Alky V6]

Two major differences in my project that would make my cam and exhaust specs completely useless to anyone else, is the fact that I will be using nitrous to help spool the turbo, and the turbo size is such that it will allow crossover in the combustion chamber.