Hustler's new engine: help him pick parts, ya'll ( a thread for power tops)
#35
I've seen a crank that was severely lightened. That and a very small clutch made that engine zing like mad. I believe it ingested a throttle screw though. Crank survived but it is for a 1.6L. I've heard theories go both ways on cutting the counter weights off the crank for an I4. Since you are going with the SuperMiata damper, I'd say go for it.
If you aren't going to need the strength for boost, why do the china rods? Few are much lighter than the factory rods. Unless of course you found a set that is considerably lighter. I'd rather spend the money on headwork magics.
For easy rev'ing how about a 1.6 based flywheel?
If you aren't going to need the strength for boost, why do the china rods? Few are much lighter than the factory rods. Unless of course you found a set that is considerably lighter. I'd rather spend the money on headwork magics.
For easy rev'ing how about a 1.6 based flywheel?
#36
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If you aren't going to need the strength for boost, why do the china rods? Few are much lighter than the factory rods. Unless of course you found a set that is considerably lighter. I'd rather spend the money on headwork magics.
For easy rev'ing how about a 1.6 based flywheel?
For easy rev'ing how about a 1.6 based flywheel?
1.6-based flywheel good. 949Racing 7.25" twindisc best.
#38
I prefer the 10.5 over the 10:1 pistons but detonation is a tricky bitch on 91 oct. The shitty thing is you just don't know where it will rear it's ugly until it's all together and being tuned. I am always amazed to see so many of the "same motors" have such different detonation personalities.
My original recommendation for a 10:1 piston was due to fuel, Texas summer temps and track conditions.
Rather than try to control detonation by lower compression I would suggest the following. With the below in mind 10:5 or more should be fine.
Add adjustable cam gears. Retarding the intake will bleed off static compression and move the power curve up the rpm band. Take the dyno torque curve and shift it over 250-500 rpms to get an ideal of what i mean.
Dyno/road tune for 91 oct but run race gas blends at the track. 93-95 oct makes a world of difference and is cheap insurance under high heat/lead situations.
I am not sure about the square top differences but my skunk2 has a nice power curve with the rotrex.
My original recommendation for a 10:1 piston was due to fuel, Texas summer temps and track conditions.
Rather than try to control detonation by lower compression I would suggest the following. With the below in mind 10:5 or more should be fine.
Add adjustable cam gears. Retarding the intake will bleed off static compression and move the power curve up the rpm band. Take the dyno torque curve and shift it over 250-500 rpms to get an ideal of what i mean.
Dyno/road tune for 91 oct but run race gas blends at the track. 93-95 oct makes a world of difference and is cheap insurance under high heat/lead situations.
I am not sure about the square top differences but my skunk2 has a nice power curve with the rotrex.
#39
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Thanks for the input on pistons. I tune cars fully heat soaked, like...if the header isn't yellow, I'm not done with the "final test", meaning I like to tune on the fuel I plan to run, with a gallon or two of 87-octane in the winter.
I basically have to advance the MSM cam 4* to make the car drivable.
I basically have to advance the MSM cam 4* to make the car drivable.
#40
As far as piston material are concerned I think the supertech ones are the best. They are a high silicon forging that expands less that other types of forgings (JE etc). This really helps with oil control. Oil control really helps control detonation.
Stock pistons are also high silicon but cast. The only downside is they are weak and more likely to shatter if subjected to detonation.
Maybe I missed it but did something happen to John's motor?
Stock pistons are also high silicon but cast. The only downside is they are weak and more likely to shatter if subjected to detonation.
Maybe I missed it but did something happen to John's motor?