Stroker costs - anyone have a rough breakdown?
12-03-2004, 06:30 PM
#16
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Originally Posted by marc@DEVEK
Some GT makes 280 rwhp and some make 309 rwhp, some S4 make 265 rwph and some make 292 rwhp, some GTS' make 675 and some make 310 rwhp.
Happy Holidays!
Happy Holidays!
12-03-2004, 07:23 PM
#18
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OK so if maximum Porsche piston to wall is .032 , .020 is the intended design , and MINIMUM is .008 per Porsche where on the scale of A B C D F do we put .0008 ? I guess I just may not know much about quality control and maintaining tolerances. If what you meant to say was .008 +.001 then I commend you for holding to the tightest factory recommended minimum since each set of 8 pistons may have as much as .014 allowable variance within one tolerance group and each cylinder would need to be bored/honed to hold a specific piston.
12-03-2004, 08:19 PM
#19
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Bailey, this whole Piston to wall thing is making me dizzy! 
JK
I seem to remember reading a Tech Bulletin about the 928 engine switching to chrome ring set and the addition or subtraction of items like the oil squatters. You guys probably know of other changes through the years.
Would some of these changes cause a need for such variances in the piston to wall clearances?
JKI seem to remember reading a Tech Bulletin about the 928 engine switching to chrome ring set and the addition or subtraction of items like the oil squatters. You guys probably know of other changes through the years.
Would some of these changes cause a need for such variances in the piston to wall clearances?
12-03-2004, 08:26 PM
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can get a rough parts list from my 85shark page link below...
my costs and opinions so far:
crank: $2400
heads (including gt heads, 968 valves, porting, new everything, etc): $5k, might save a buck or two but don't try this on the stock valves/motor has to breathe w/a 28% increase in displacement - so be ready...
pistons: $1200
block work: $1200
head gaskets: $200
other gaskets: $350
rods: $1150
AL radiator: $500
hoses (est): $300
injectors: $225
balancing: $800 (est)
block work/blueprinting/clearancing:$400 (est)
build labor: approx 40hrs @100/hr (est)
shipping: $400 (est)
bearings: $400 approx(they need work for the crank)
harmonic balancer: $350/approx (don't try this w/the old one)
cams: $1800 for reground GT stuff (700 regrind/1200 for cams)
tbelt system stuff: $500 approx (don't try this w/used stuff or you'll be a frequent poster)
powdercoating: $400 approx (all that work and it's ugly?? no way)
exhaust (gotta breathe): whatever
motor mounts: $250/porsche stuff/other options exist
other stuff: lots of stuff is accessible w/the motor out - misc hoses, etc... depends on you/condition of stuff
airbox/ducting mods: not there yet, but I know it'll need something
tuning: dyno costs vary, depends on how much you want to tweak it...
adjustible fuel reg: $195
motor installation: whatever
dont' forget your torque tube, trans, brakes...good time to make sure they are up to snuff for the extra power...
time: yep... lots of research, blunders, mis-information to muddle through, so it took me a while just to decide on a strategy (ie nicom vs alusil, valves, cams, etc) want it done right or fast???
you can sell off lots of the used stuff, that helps a bit...
ps: I have an extra set of 104mm (968) JE pistons for sale, only $680.00... if I had a block that was cleaner, and heads that didn't need a ton of milling, could have been fine... could have reworked them, but JE cut me a killer deal, so I'm selling these for what the new ones cost me at the Jobber level... paid $1200 for the 1st set, and so will someone else unless they jump on these...
keep in mind every situation is different... I'm converting an 85 to GT/custom specs so I had to do some stuff you won't... others may need more/less... worth it? a subjective call... it is a monster zero time motor good for another 100k or so miles, that'll pass smog w/any luck... compared to an OEM overhaul, it's not much different cost - so I think/hope so... did meet lots of cool gearheads and learned lots of interesting porsche/tech stuff... can't wait to drive it...
I'm not going to total it up, and I'd rather not see the total either... in fact, me go have drink now... back to the bat cave...
hope this helps....
regards!
my costs and opinions so far:
crank: $2400
heads (including gt heads, 968 valves, porting, new everything, etc): $5k, might save a buck or two but don't try this on the stock valves/motor has to breathe w/a 28% increase in displacement - so be ready...
pistons: $1200
block work: $1200
head gaskets: $200
other gaskets: $350
rods: $1150
AL radiator: $500
hoses (est): $300
injectors: $225
balancing: $800 (est)
block work/blueprinting/clearancing:$400 (est)
build labor: approx 40hrs @100/hr (est)
shipping: $400 (est)
bearings: $400 approx(they need work for the crank)
harmonic balancer: $350/approx (don't try this w/the old one)
cams: $1800 for reground GT stuff (700 regrind/1200 for cams)
tbelt system stuff: $500 approx (don't try this w/used stuff or you'll be a frequent poster)
powdercoating: $400 approx (all that work and it's ugly?? no way)
exhaust (gotta breathe): whatever
motor mounts: $250/porsche stuff/other options exist
other stuff: lots of stuff is accessible w/the motor out - misc hoses, etc... depends on you/condition of stuff
airbox/ducting mods: not there yet, but I know it'll need something
tuning: dyno costs vary, depends on how much you want to tweak it...
adjustible fuel reg: $195
motor installation: whatever
dont' forget your torque tube, trans, brakes...good time to make sure they are up to snuff for the extra power...
time: yep... lots of research, blunders, mis-information to muddle through, so it took me a while just to decide on a strategy (ie nicom vs alusil, valves, cams, etc) want it done right or fast???
you can sell off lots of the used stuff, that helps a bit...
ps: I have an extra set of 104mm (968) JE pistons for sale, only $680.00... if I had a block that was cleaner, and heads that didn't need a ton of milling, could have been fine... could have reworked them, but JE cut me a killer deal, so I'm selling these for what the new ones cost me at the Jobber level... paid $1200 for the 1st set, and so will someone else unless they jump on these...
keep in mind every situation is different... I'm converting an 85 to GT/custom specs so I had to do some stuff you won't... others may need more/less... worth it? a subjective call... it is a monster zero time motor good for another 100k or so miles, that'll pass smog w/any luck... compared to an OEM overhaul, it's not much different cost - so I think/hope so... did meet lots of cool gearheads and learned lots of interesting porsche/tech stuff... can't wait to drive it...
I'm not going to total it up, and I'd rather not see the total either... in fact, me go have drink now... back to the bat cave...
hope this helps....
regards!
Last edited by rob rossitto; 12-03-2004 at 08:58 PM. Reason: more detail
12-03-2004, 08:34 PM
#23
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Marc wrote:
Here's my first (of many) lessons learned about stroker building.
I had my block over-overbored by .0015". The reason for this is that the Porsche spec was .0008", and then the min tol for the HPC coating was .0007". My (mis)understanding was that .0007" was still within Porsche spec. When I measured the end gap on my rings, they were too wide. Factory is .20mm to .40mm. Mine were .58mm comp/.50mm scraper. The oil retaining ring was in spec.
I never would have guessed in a million years that that minor of an overbore would create too large of an end gap. Live and learn.
Anyone looking for a set of 8 new, never opened (except 1) 968 standard bore ring sets?
I'll make you a great deal.
100.00 - 99.98 = .02mm = (.02 x .03937) = .0007874" or for the mis informed, .0008"
I had my block over-overbored by .0015". The reason for this is that the Porsche spec was .0008", and then the min tol for the HPC coating was .0007". My (mis)understanding was that .0007" was still within Porsche spec. When I measured the end gap on my rings, they were too wide. Factory is .20mm to .40mm. Mine were .58mm comp/.50mm scraper. The oil retaining ring was in spec.
I never would have guessed in a million years that that minor of an overbore would create too large of an end gap. Live and learn.
Anyone looking for a set of 8 new, never opened (except 1) 968 standard bore ring sets?
I'll make you a great deal.
12-03-2004, 08:51 PM
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HA! (in my best arnold voice) sounds like little girly man tols to me!! (LOL) with my forged JE's, both JE and Millinium recommended piston to wall tols of .0035" w/forged pistons over 4.000"... sounds like I could drive a mini cooper in there compared to you guys... even more is recommended for turbo/supercharged stuff!! guess forged plays by slightly different rules for expansion, etc...
mark, I'm quite sure you're worth every penny... you, greg, atb, et al all have my respect for sure...
atb, those rings will also work in a nicom bore, if anyone asks... anything but high tension chrome is ok, according to millinium...
mark, I'm quite sure you're worth every penny... you, greg, atb, et al all have my respect for sure...
atb, those rings will also work in a nicom bore, if anyone asks... anything but high tension chrome is ok, according to millinium...
12-03-2004, 09:05 PM
#26
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That is too funny I guess I just never expected someone building metric motors to be quoting tolerances in inches , That truely made me laugh . Thanks Marc I needed that Is that not how NASA lost a Mars probe ?? besides I have been called worse things.
Is that not how NASA lost a Mars probe ?? besides I have been called worse things.
12-03-2004, 09:39 PM
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Since "stroker" was all that was initially mentioned, keep in mind that cost can depend on whether you're planning on 6.0 liters, or 6.4 liters. If you're set on the larger 6.4 liters, and your block doesn't have the cylinder wall thickness to go that big due to core shift, you can add in the cost of another block to the parts list.
12-03-2004, 09:39 PM
#28
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Originally Posted by Jim bailey - 928 International
That is too funny I guess I just never expected someone building metric motors to be quoting tolerances in inches , That truely made me laugh . Thanks Marc I needed that Is that not how NASA lost a Mars probe ?? besides I have been called worse things.
Is that not how NASA lost a Mars probe ?? besides I have been called worse things.want the ultimate metric-standard screw up...
just a small segment about the "Gimli Glider"
google if you want the whole story.
At 1:21 GMT, the forty million dollar, state-of-the-art Boeing 767 had become a glider. The APU, designed to supply electrical and pneumatic power under emergency conditions, was no help because it drank from the same fuel tanks as the main engines. Approaching 28,000 feet the 767's glass cockpit went dark. Pilot Bob Pearson was left with a radio and standby instruments, noticeably lacking a vertical speed indicator - the glider pilot's instrument of choice. Hydraulic pressure was falling fast and the plane's controls were quickly becoming inoperative. But the engineers at Boeing had foreseen even this most unlikely of scenarios and provided one last failsafe&emdash;the RAT.
The RAT is the Ram Air Turbine, a propeller driven hydraulic pump tucked under the belly of the 767. The RAT can supply just enough hydraulic pressure to move the control surfaces and enable a dead-stick landing. The loss of both engines caused the RAT to automatically drop into the airstream and begin supplying hydraulic pressure.
As Pearson began gliding the big bird, Quintal "got busy" in the manuals looking for procedures for dealing with the loss of both engines. There were none..
The RAT is the Ram Air Turbine, a propeller driven hydraulic pump tucked under the belly of the 767. The RAT can supply just enough hydraulic pressure to move the control surfaces and enable a dead-stick landing. The loss of both engines caused the RAT to automatically drop into the airstream and begin supplying hydraulic pressure.
As Pearson began gliding the big bird, Quintal "got busy" in the manuals looking for procedures for dealing with the loss of both engines. There were none..
Now back to your regular programming....
12-03-2004, 10:14 PM
#29
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Tony unbelievable story and illustrates that once you have a certain mindset it is too easy to explain away what should be obvious signs of what is really happening...so do the manuals now have glider instructions ??
12-03-2004, 11:21 PM
#30
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Hi.
Well one of the reason that we never went to the metric system, is because fractions actually make much more sense to computers and provide for faster clock speed and data calculations. There are big arguements about this every year at MIT in the Computer Science department and Mathematics.
The metric system is nice for most applications, however, but also consider that so much of industry in this country is based on SAE standards that it would be very costly to small business to switch to the metric system, especially small industry.
Hey Marc, now I know that we went to different engineering schools, but did they actually teach you that you can gain accuracy beyond your inital significant digits? Just poking fun at somthing I am surprised you didn't catch. All for a good laugh.
Take care.
Well one of the reason that we never went to the metric system, is because fractions actually make much more sense to computers and provide for faster clock speed and data calculations. There are big arguements about this every year at MIT in the Computer Science department and Mathematics.
The metric system is nice for most applications, however, but also consider that so much of industry in this country is based on SAE standards that it would be very costly to small business to switch to the metric system, especially small industry.
Hey Marc, now I know that we went to different engineering schools, but did they actually teach you that you can gain accuracy beyond your inital significant digits? Just poking fun at somthing I am surprised you didn't catch. All for a good laugh.
Take care.