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Old 09-16-2019, 04:53 PM   #341
Nick M3
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Quote:
Originally Posted by John V View Post
Jerico makes transmissions (manuals). Bellhousings are engine specific.

Fortunately, Mazda made the automatic NC and it has a bolt-on bellhousing.
Well, that saves a lot of effort. You going 2 speed for minimum weight?
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Old 09-16-2019, 05:38 PM   #342
John V
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I'm not really sure. I kind of feel like the answer is yes, although part of me thinks I should put a four speed in there just in case I ever want to take it to the track. But I haven't been to the track in over twenty years, and I'm not putting a cage in this car, so then I think I should just put the two speed in it.
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Old 09-19-2019, 07:01 AM   #343
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So, a two speed isn't an option. When I looked at the gearing charts for the two speed I realized that second gear is always 1:1, so that doesn't really work with any realistic rear-end ratio I would run.

I'm actually looking now at a G-Force GSR transmission. It's configured similarly to the Jerico, but the G-Force has internal shift rods which allow the shifter to be centered in the tunnel. The side shifter and external shift rods on the Jerico look like they're going to cause problems in the RX-8 tunnel.

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Old 09-19-2019, 09:56 AM   #344
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Quote:
Originally Posted by John V View Post
So, a two speed isn't an option. When I looked at the gearing charts for the two speed I realized that second gear is always 1:1, so that doesn't really work with any realistic rear-end ratio I would run.

I'm actually looking now at a G-Force GSR transmission. It's configured similarly to the Jerico, but the G-Force has internal shift rods which allow the shifter to be centered in the tunnel. The side shifter and external shift rods on the Jerico look like they're going to cause problems in the RX-8 tunnel.
I'm sure it's a dumb question and not up on all the rules, but are transmissions basically completely open for whatever in Street Mod?

Your option looks pretty awesome, but I assume you can easily get the gearing where you want it for autocross?
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Old 09-19-2019, 04:22 PM   #345
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Drive train is almost completely open. It's a bonkers rule set.
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Old 09-19-2019, 05:12 PM   #346
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Just caught up on this thread. Wow on the piston destruction. Enjoy the rebuild!
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Old 10-07-2019, 05:50 PM   #347
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Moving slowly on all of this. I finally got the new (used) engine completely torn down, cleaned, honed and inspected. I'm happy that I got a good engine from the salvage yard, so now the buildup starts.

Cylinders honed with a ball hone, then the entire block was washed including every bolt hole, then blown dry with compressed air, then the cylinders oiled.



The new rods and pistons are just a little more beefy looking than the stock stuff.



Cylinder head was torn down to receive new valve springs, shims and retainers to allow a little more headroom on redline - 8,000 RPM vs 7,500.



Valve springs have more seat pressure than the stock ones.



Cylinders were measured to be round within the tolerance of my dial bore gauge (0.0005"). The piston to bore clearance is 0.0055" which is above Wiseco's recommended minimum of 0.0035".

All crankshaft journals were in spec, and every bearing clearance is on the large end of the spec at 0.003". The spec is 0.0009" (!) to 0.0039" for both the rods and the mains.

The oil rings and 2nd compression rings all were within spec out of the box, but the top compression rings will need filing. The recommended ring gap for a boosted application is 0.0055" times the bore diameter which is 3.5", so about 0.019", and they came out of the box at 0.014" which is too tight. I'm borrowing a buddy's rotary ring file so when that arrives this week I should be able to finish that up. The bottom end gets new stock main bolts from Mazda which are inbound. The cylinder head is getting ARP studs. Probably not necessary at the boost levels I'm running but if I ever creep closer to 500hp they will be welcome insurance.
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