Engine opinions needed

[Legend]

Well I am mid rebuild of my 81 GS1000GL I have given my cylinder head and block to a qualified shop to look over and have come back with some news and now I have to decide just what I am going to do.

So I thought what better than to ask the GS guru's on the site. So here goes.

Pistons need to be replaced and cylinders bored

Question is Do I rebore for oversized pistons and rings at a cost of approx $650

Or do I rebore for the wiesco 1085 kit for approx the same price if not cheaper.

Has anyone had any bad experiences with the big bore kits. And does the 1085 need sleeves? Anything else I should look out for?

 

[Spyderman]

if it's gonna cost about the same then go with the 1085 kit
1085 kits is a bore only no sleeves no case boring either
if they have your head you may as well get the valve stem seals done now too and get your valves and guides checked to be sure they are still in spec

 

[Legend]

Yes head is being completely redone. Not gonna go this far in and skimp out on the head, debating on spending some time to port and polish the head as well, anyone got any suggestions?

 

[koolaid_kid]

I ran Wiseco pistons on my dirt bikes and RD350s, and the GPz has a set. I like them.

 

[Nessism]

I'm rebuilding my second chain drive 1000 engine and both were put together from parts gathered from either ebay or here. Unless you are in a hurry you can find low mileage cylinder heads and cylinders and pistons on a std bore for about $100 each shipped (or even less if you get lucky). I'm awaiting on a cylinder and pistons right now and there is a 13k mile cylinder head on ebay right now too. Beats the heck out of paying $1000 to have your current head/cylinder serviced.

 

[Legend]

I totally get what your saying Nessism, but I am the kinda guy that perfers to just put the work into it rather than hoping someone on ebay or where ever is telling me the truth about motor parts. Have been burned on that before and hope to get many many miles out of this bike, so would feel much better knowing exactly what is going on with the heart of the beast. And as my Daddy always taught me, better to do it right the first time then to have to pull it all apart later because I was trying to save a few bucks. That and shipping to Canada can be a real pain in the ass with heavy items.

 

[mac1170]

gday mate, go wiseco, and enjoy the extra torque, and horses, regards.

 

[Steve]

... debating on spending some time to port and polish the head as well, anyone got any suggestions?

You gonna ride on the street or the strip? :-k

Polishing will smoothe out the walls, allowing a bit more air flow at high rpm, but those little irregularities
actually help at lower speeds by inducing a bit of turbulence that helps keep the atomized fuel in suspension.

.

 

[Nessism]

I totally get what your saying Nessism, but I am the kinda guy that perfers to just put the work into it rather than hoping someone on ebay or where ever is telling me the truth about motor parts. Have been burned on that before and hope to get many many miles out of this bike, so would feel much better knowing exactly what is going on with the heart of the beast. And as my Daddy always taught me, better to do it right the first time then to have to pull it all apart later because I was trying to save a few bucks. That and shipping to Canada can be a real pain in the ass with heavy items.

I get it but the cost give me pause. GS1000 exhaust valves cost $43 each and intakes are $25. Valve guides are $70/set for aftermarket (even more for OE). Installing these parts and performing a valve job is about $250.

When rebuilding my first 1000 engine I was ready to purchase the cutters to perform my own valve jobs but the cost of those gave me pause too.

I'm seriously into quality and keeping everything in spec, but I found it far cheaper to purchase a complete used head, you could even purchase several of them until you found something that measures out the way you like and still come out ahead.

 

[koolaid_kid]

You gonna ride on the street or the strip? :-k

Polishing will smooth out the walls, allowing a bit more air flow at high rpm, but those little irregularities actually help at lower speeds by inducing a bit of turbulence that helps keep the atomized fuel in suspension.

.

Porting, or general things like unshrouding the valves and work that will increase air flow, is what you would want. I don't know the airflow characteristics of that head, probably racers such as rapidray might be better suited for answering that.
If it were mine, I would just get a quality valve job done (we do 3 or 5 angle valve jobs on our cars, not sure for bikes). I milled the head on my GPz to raise compression, but I have to degree the cams now because of it, a real PITA.

 

[nisom512]

I get it but the cost give me pause. GS1000 exhaust valves cost $43 each and intakes are $25. Valve guides are $70/set for aftermarket (even more for OE). Installing these parts and performing a valve job is about $250.

When rebuilding my first 1000 engine I was ready to purchase the cutters to perform my own valve jobs but the cost of those gave me pause too.

I'm seriously into quality and keeping everything in spec, but I found it far cheaper to purchase a complete used head, you could even purchase several of them until you found something that measures out the way you like and still come out ahead.

I have to go with Nessism on this one. plus who knows if the shop will get it right. if you get a used block you know its to spec. Plus going bigger also means messing with jets, and that gets kind of annoying.

and from all the people who have told me to do it right the first time there response to me modding something away from stock was usually shunned upon.

either way...good luck
jake

 

[Legend]

Thanx for the info on porting, don't think I will go that route yet. Would like to keep the low end reliability.

Nisom512 I agree going away from stock always adds more to it in the end, but the cylinders are in need of a bore, so it would be beyond stock anyways, so may as well make it worth it and gain some more ponies out of it, for the same price.

I am not sold on the idea of buying someone elses used motor parts based on a personal claim. Like I said, have been burned in this department before, and rather than hope someone is truthfull I would rather bite the bullet myself now than take one in the backside later.

And jetting issues are not a huge worry, I have tuned many carbs over the years. Also have access to a dyno to get the fine tuning in check.

So it seems I may be going with the weisco kit. Unless someone can give me a good reason not to.

Thanx Again fellow GS'ers

 

[Nessism]

I never buy engine parts based on claim either, I ask how many miles are on the engine. When I bought a cylinder head on ebay it was part of a parted bike, and the guy had the instrument cluster so it was easy to verify the mileage.