S3 Race Custom Modified EC250 Complete Rebuild

[(F5)]

if SKF put their name on it it will be a commissioned bearing factory & won't matter what country it was made in I'd bet. if it was a no-name brand then all bets are off.

[GMP]

Cranks are balanced for a certain RPM, called balance factor. This is part of the crank design and within production tolerances. That said, it can be improved. Do a search, a member here had his rebuilt and precision balanced with great results.

The '99 and '00 motors had a full circle 10oz. weight on the primary. This went to an 8oz. eccentric in '01, and back to a full circle(but heavier/thicker looking) weight in '12.

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[Jakobi]

Good info.

Today I have been going slow and steady again. I discovered my kinchrome torque wrench doesn't click in reverse. I undid the primary nut and redid it by feel using another bolt in the vice to guage the amount of pull required. Basically ended up where I was again anyway, but I have piece of mind now. Clutch went back together no worries. Gearshaft/scorpian and seal all no issues there. I'm actually getting a greater understanding of how it all works by doing this too. Kind of looking forward to the next time. Things should go much smoother.

Onto the powervalve, and I'd like to know what the shims are. From the exploded diagram it says the shims sit at the rear of the spring against the pinion and preload the spring. I have none here. Up at the governor end I have 2 x thrust washers, a spacer and 3 washers keeping everything separate. I was going to remove some shims for a harder hit down low but it doesn't look like I have any. Am I missing anything?

[GMP]

PV governer setups are all over the map, I think they test and shim as needed to match spec.


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[Jakobi]

I hear you. I used my brain and definitely no way I can remove anything up the other end. Its all vital to the function of the PV. I may experiment with preloading the spring at some point and seeing if I can get it to open a bit later even. More for curiosities sake than anything else.

In regards to the build, all the new challenges are done. Just have to button up the top end, take a squish measurement with the new base stack, and decide which coloured head to use. I'm thinking I'll stick with gold because it matches the price of my suspension and well.. I don't have to dig it out of a box

[Jakobi]

And she comes along a bit more. Should be done tomorrow. That pesky water pump pending!

[Jakobi]

I went with 2 x 0.3mm base gaskets. As expected this pulled my squish out to 1.35mm and should drop my compression ratio a touch. It'll be interesting to see how she runs now. Hopefully some mild gains in top end.

[Jakobi]

I added some more preload to the pv as well. It would rest against the stop previously but only lightly. Reeds back in. LHS PV and 1 x 8mm spacer installed. Head torqued down. Shes nearly there.

[lonetree]

almost all done. good work!
thank you very much for putting this all together, i have learnt heaps...
i will have heaps more confidence, with this thread as a referance when i have to do my GG's bottom end. makes my top end rebuild seem easier too...
big thumbs up!

[Jakobi]

No worries. Hope it helps a bit. Had my fair share of challenges along the way and spent about 4 times longer than I should. Pull things apart and put them back together 3 times just to be sure its right.

Speaking of which, I've noticed the PV governor and actuator seem to have more resistance at some points in its action than others. Like the spring doesn't offer even resistance all the way around. One side feels really good. The other feels a bit slack but still comes back to the stop. Is that normal or should I pull it back out and double check everything again? It also seems to feel a bit more slack if I lay the engine on its side as opposed to standing up. I'm thinking it might come good once I put the outer cover back on and locate the other end of the shaft in its bearing.