Engine Build Advice for 78 GS1000 Roadracer

[rcp]

i am going to kal gaurd https://www.kgcoatings.com/index.php?_a=viewProd&productId=20 the engine and headers.

it was good enough for Pops, gives about a 15% cooling according the a old bike magazine artical.

That's the stuff I'm thinking about - about $300 CDN to do an entire engine according to a Canadian distributor, so it gave me pause. Wanted to see if there's not a newer, better alternative. The Kal-Guard coating requires baking in the oven, so the engine has to be disassembled (which it is), and the wife and kids need to be out of the house .

Richard, ceramic coatings on the header help keep the heat in the PIPE which keeps other parts around it cooler & helps get the heat out of the motor. As for coatings INSIDE the motor, the only thing I would do is have the piston skirts dry film lubricant coated. Ray.

Thanks Ray, I thought the ceramic must be an insulator. Therefore the best header treatment would be one that does the inside of the pipes as well as the exterior, right?

I wonder why they're putting ceramic in rattle-can engine paints?

As clarification, I was only thinking external coatings. I would assume that the dry film lubricant on piston skirts falls into the category of "insurance". If this something you would generally recommend? Are you talking about a PTFE/Teflon coating or something else?

- Richard

 

[rcp]

I would save a few bucks and keep the oem studs. I am running oem, just bought some new ones. They were good enough for Pops. The HD studs are bigger in dia and I don't like the idea of reducing oil flow to the head.

Easily eliminated by drilling the cylinders and using GSXR o-rings to seal the head. Cylinder and head gasket must be properly bored to use the o-rings. Did it for years on a pro mod and never leaked a drop. I also used studs bigger than APE.(Elmer Trett made them especially for nitro/turbo applications.) No oil gear either.

I'll have to compare the GSXR against the GS - I hadn't considered the possibly tighter oil passages from H.D. studs. Are the H.D. studs actually greater in diameter or just of greater tensile strength?

My thinking was that greater compression might require the H.D. studs to avoid stretching them. I'm not going crazy with power from this engine - want to keep the broad torque curve to maintain rideability on our majority tight, twisty tracks - but I want to make sure I build in reliability as I increase the output.

- Richard

 

[reddirtrider]

I'll have to compare the GSXR against the GS - I hadn't considered the possibly tighter oil passages from H.D. studs. Are the H.D. studs actually greater in diameter or just of greater tensile strength?

My thinking was that greater compression might require the H.D. studs to avoid stretching them. I'm not going crazy with power from this engine - want to keep the broad torque curve to maintain rideability on our majority tight, twisty tracks - but I want to make sure I build in reliability as I increase the output.

- Richard

They're greater in diameter. If you use them you need external oil lines to feed the cams. The money starts to escalate rather quickly.

 

[Guest]

They're greater in diameter. If you use them you need external oil lines to feed the cams.

which can't be done on an 8 valve. I wouldn't worry about the studs. Buy new stock ones and be done with it. I've never heard of the studs being a weak point.

 

[first timer]

about the studs, i have also heard it's hard to get hd studs for the gs8v ape doesn't stock them and would have to make some if ordered. They are bigger dia because of the rod they use is imperial sized (cheaper in price then metric), i have heard they just cut it down for the threads. Please correct me if i am wrong. You hear lots of thing over this interweb.

I'll let you know how much it is do an engine, I was going to have a powder coat place just do it (i ordered the coating). But if you are thrifty find a place to blast with the media KG recomends) and just get a cheap harbor freight gun and do it yourself, I have been told by kg it's not that bad in the over

 

[rcp]

APE doesn't list the Heavy Duty studs for the GS1000, but is able to put together and sell a set from studs they use in other engines. Going to be ordering some tomorrow.

 

[rcp]

Gear engagement dog wear

Gear engagement dog wear

I've had no trouble from this, so could probably run them longer, but am taking them over to a local machinist to see about cleaning them up.

The 1st and 2nd gears use larger oval-ish dogs that fit into oval slots cut into the output gears, and those seem fine, but some of the inclined plane meets inclined plane engagement dogs are slightly rounded and one or two are lightly chipped.

I think it's probably ok just to get the damaged surfaces machined to match their mates. Not sure if that's cost effective, but the budget's certainly no longer there for a full undercut job from the likes of APE. I'm going to check the specs and parts fiche for the GS1000G, and if things look like they interchange, may pull the oil pan cover from my GS1000G and inspect the gears in that engine.

- Richard

 

[rapidray]

You DEFINITELY need to rework the dogs! It will only get worse if you don't! Ray.

 

[rcp]

You DEFINITELY need to rework the dogs! It will only get worse if you don't! Ray.

Annoying how metal never heals itself, eh?

I'll see about the local machinist, but don't think he's done motorcycle transmissions before, so won't be surprised if it takes too much setup time and jig-making to be economical.

For alternatives, I've cross-referenced the GS1000G gear part numbers. None of the parts numbers match, but all the teeth counts are the same. So that might be worth looking at, although the layout of the two transmissions are very different. And there's some transmissions on ebay at the moment.

- Richard

 

[Guest]

Annoying how metal never heals itself, eh?

I'll see about the local machinist, but don't think he's done motorcycle transmissions before, so won't be surprised if it takes too much setup time and jig-making to be economical.

For alternatives, I've cross-referenced the GS1000G gear part numbers. None of the parts numbers match, but all the teeth counts are the same. So that might be worth looking at, although the layout of the two transmissions are very different. And there's some transmissions on ebay at the moment.

- Richard

I think I might have a spare 1000 tranny. Do you want me to look?

 

[rcp]

I think I might have a spare 1000 tranny. Do you want me to look?

Thanks Bruce, please do.

I talked to the automotive machinist this morning, and he can't help me. So I'm looking for either replacements or a machinist that can do it. There's a pair of '77 GS750s being parted out by a local vintage racer, so I may be able get a transmission out of those, and most of the gear part numbers in that model do cross-reference against the GS1000.

- Richard

 

[Guest]

Thanks Bruce, please do.

I talked to the automotive machinist this morning, and he can't help me. So I'm looking for either replacements or a machinist that can do it. There's a pair of '77 GS750s being parted out by a local vintage racer, so I may be able get a transmission out of those, and most of the gear part numbers in that model do cross-reference against the GS1000.

- Richard

Well, I looked. I thought I had a spare tranny....what I have is the shift drum and forks. Sorry about that.

You might check with Wazz? I think he was parting out a 1000? Or post in the parts wanted section. Someone is bound to have one.

 

[first timer]

just get those rounded dogs recut by ape, you don't have to have them cut all the gears just the ones rounded. They will end up hard welding the dogs to build them up (which is good) and then they will back cut them. My dogs looked just like yours. The hard welding will help keep the dogs from rounding again. If you use any used gears they will just round off again especially if you are racing on them.

 

[rapidray]

Richard, you could also have the trans done by Fast By Gast as they are in upstate New York & a LOT closer to you than APE. Ray.

 

[rcp]

Thanks for the reminder that Fast by Gast does that work. I talked to them and got a price. They'd probably be the best option, but undercutting is out of my budget for now.

I'm picking up the 77 GS750 bottom end on the weekend, or early next weak, as that also gets me the oil pump gears I need, and I've also got an inspected 1000 transmission coming for a reasonable price from ebay. Whichever transmission is suitable and ready to install first will go into the cases.

Speaking of cases, I need to post some pictures.

- Richard

 

[rcp]

Case cleanup

Case cleanup

Before, nothing but a bit of solvent:

Into the dishwasher (before wash, after solvent and wire brushing):

The top rack didn't work so well - here's after one wash.

 

[rcp]

Case cleanup - after dishwasher

Case cleanup - after dishwasher

Still need to do soda-blasting on the lower crankcase. I tried the upper where I cleaned it with solvent and hand, drill and die-grinder powered brass wire brushes (soda blasting does nothing to oily goo), then washed it in the dishwasher. The lower I just cleaned almost all grease and grit off of with wire brush and solvent and ran it through the dishwasher - then I will soda blast it to get the remaining hard crust and paint off. I think the brush/degrease->dishwasher->soda blast->final wash will be the winning combination.

- Richard

 

[Guest]

So, your wife must really love you to let you use her dish washer! :clap:

Mine is just now getting used to me using her oven for paint baking and boiling carbs on the stove.

 

[steve murdoch]

I boil the carbs on the old barbaque that only gets hot in one spot. Keeps that lovely smell outside and only person annoyed is the neighbour.

 

[Guest]

The full size studs have never caused loss of oil flow to the top end on any GS motor.

Jay