GS400/500 Gr650 Hybrid engine

[Rensdw]

Custom high compression GR650 pistons

Custom high compression GR650 pistons

I just called wiseco, they are asking a very good price per piston, a complet kit is going to cost aprx. 300-350.
They have to make a minimum of 12 pistons, so....... Who is interested?

the pistons will be made to gr650 specs except the dome, compression will be raised to 10.5:1 static.
Not sure about gr650 stock camshaft valve clearance, im going to use custom camshaft so i dont worry about it.

 

[Chuck78]

Hmmm... To get 6 GS/GR owners interested in this, I would think it'd be a lot more appealing if you had them made in a +.5mm oversize (or +1.0mm o.s.) for current GR owners to have more of a reason to purchase/upgrade to these. 5 more people to buy. The GR is rare, so you'll have to post a specific thread on here. Dotheton.com, maybe caferacer.net in order to get more people interested.

JE Pistons will make one-off runs if you cannot find 5 more people. Carrillo "CP" makes the absolute best, lightest, & most advanced pistons, so for the weight factor alone, I would be contacting them if I were you. In your case, you are going with a much larger bore than stock, so with a bigger piston, its very critical to keep the piston weight within 10% of the original piston intended for that crankshaft. The CP will be the lightest (& best in every category by far, other than price).

 

[Rensdw]

Hmmm... To get 6 GS/GR owners interested in this, I would think it'd be a lot more appealing if you had them made in a +.5mm oversize (or +1.0mm o.s.) for current GR owners to have more of a reason to purchase/upgrade to these. 5 more people to buy. The GR is rare, so you'll have to post a specific thread on here. Dotheton.com, maybe caferacer.net in order to get more people interested.

JE Pistons will make one-off runs if you cannot find 5 more people. Carrillo "CP" makes the absolute best, lightest, & most advanced pistons, so for the weight factor alone, I would be contacting them if I were you. In your case, you are going with a much larger bore than stock, so with a bigger piston, its very critical to keep the piston weight within 10% of the original piston intended for that crankshaft. The CP will be the lightest (& best in every category by far, other than price).

Thank you for this information, very helpful, I will certainly be contacting those companies tomorrow.
I was thinking about keeping 3 sets for myself, for future projects, that leaves 3 kits to sell.

 

[Rensdw]

I have contacted cp carrillo and they are going to make me a single set of pistons, maby even the rod I forgot to ask.
Anybody interested in buying my gr650 cilinders? Its on ebay.

 

[Rensdw]

First: I would still like to have this topic moved to "Performance/Tuning/Mods" if one of the moderators reads this, please move this topic.


So, not a whole lot has happened, CP Carillo is done making my pistons but the rods are still in the making, that is going to take another month or so.

I did paint my engine, here some pictures:

First a nice high quality basecoat.




And 5 layers black paint and three layers clear coat later:
(All the white dots are reflections, there is a lot of lights in the hangar )





Little bit of dust in the paint here ;/ not bad for a outside paintjob though.








Also most of the aluminium is polished, like a mirror!





Next I will have to make the cilinder and head look pretty, I need to finish the external oil lines and then build up the bottom end.
All the chain guides seem to line up nicely, more on this later.

 

[Chuck78]

Wow. Nice.

CP, the best. Can't wait to have them make some 502cc gs425 pistons for next year's project bike build.

 

[hank3fan]

Any updates?

 

[Guest]

I missed this thread... wow!

 

[Rensdw]

Well, no real updates.

Apparently my pistons are ready, the rods are not..... they are taking their time.

And since my visum expired I am no longer in the united states, I'm back in the Netherlands, my engine is still in Texas.
Trying to get it back in one large shipment together with a snap-on toolbox but it is taking a long time unfortunately.

Thanks for the interest though I'm eager to continue my work!

 

[Rensdw]

Back in the USA for two weeks and finally got to hold these precious babies in my hands:

GRTZ, Rens

 

[Rensdw]

I made this because I am researching shim under bucket conversion, If I buy a kit for the GS1000 I might be able to do both my Hybrid and my GS500E.

Ordered from here, hope this fits, call it an experiment

 

[GregT]

For what it's worth, I've used standard GS buckets with the tops ground or machined flat as the buckets for shim under use. They are hardened right through as far as i can tell. Certainly the flat tops are showing no discernable wear so far...All you have to do then is find a shim holding retainer. Rather than the fairly heavy kawasaki 650 retainers which are quite popular, I remachined some Ti Nissan retainers which use a 10mm dia shim. Light...
You can also add another motor using that size bucket to your list - The Rotax/BMW singles are the same. I did a shim under on one for racing using the ground GS buckets as described...

 

[Rensdw]

Thanks GregT, that is some good information!
I don't think the buckets are hardened at all, the shims are, anybody that could confirm this? anyway; it doesn't seem to matter since you had a good experience with ground off buckets.
How much power did yours produce?



Also ordered a C5 optical ignition system for this build, fully programmable you just need to use a laptop

 

[GregT]

The buckets are definitely hardened...FWIW we're using them with cams giving over .440in lift and spinning the GS1000 roadrace motor to around 10,000 rpm...
Not exactly an easy life...

 

[Rensdw]

Not an easy life indeed, Did you use custom valves?

 

[GregT]

Not an easy life indeed, Did you use custom valves?

Initially, no. But after having an OE valve come apart at the collet groove, we've gone to APE stainless.

 

[Rensdw]

Initially, no. But after having an OE valve come apart at the collet groove, we've gone to APE stainless.

With your experience, would you advise me to get custom SS or titanium valves? keep in mind that this will be a road-bike, not a racer.

 

[GregT]

With your experience, would you advise me to get custom SS or titanium valves? keep in mind that this will be a road-bike, not a racer.

Definitely not titanium for a road bike.
Custom stainless has some pitfalls too. We went APE for the 1000 because we knew where the blanks came from. Other outfits advertising suitable valves would not disclose where they were getting the blanks which was not satisfactory for me.
Specifically I've had bad results with ferrea valves as what was on the box was not what we got...There are basically three grades of stainless valve and for an air cooled motor you need the absolute top grade material. We didn't get that despite the packaging saying it was...And yes, after failure I had them tested.
I can obtain Manley stainless blanks locally so any replacement valves will come from those blanks. The head shop carrying them are happy to make up pretty well any size valve for me.

 

[60ratrod]

I'm following this cause i love the fact you are looking at this as a journey, not a half hatched idea. I love one off stuff

 

[Rensdw]

I'm following this cause i love the fact you are looking at this as a journey, not a half hatched idea. I love one off stuff

Thanks

The idea is that this is the first bike I ever had, I did about 15K miles in 5 months on it in the UK during an internship, countless hours of fun.
Riding the bike for EVERY SINGLE DAY never got old, I had some serious near-death moments and moments of laughter.

I remember this one time I had to go out of bed early, (the morning is not my best moment of the day, (amnesia)), and I came up to the very first corner and did just plain forgot to steer.
So there I am; 6AM in the morning, somewhere on the side of an idyllic English country road, trying to get myself out of the bushes, woken up by an OD dose of adrenaline.
I got on my bike again and drove off thinking; **** **** **** that was stupid! g*d*mn*t! but that quickly turned into having to stop because I laughed so hard thinking about myself laying there in the bushes all by myself.


I will try to never sell this bike, and I will put some serious money in this bike to make it like I want it.
It will also act as an showcase, I would like to build some bikes for customers when i'm done.