Tcat engine build! how to get 1150cc! does head shaving increase stroke?

[hickatvracer17]

First off. I have a 1995 Tcat 900.

First question: Does shaving a head basically increase stroke? so 1 mm off the head would be equivilant to a plus 1mm crank?

Heres the deal. I want to take stock 1000cc tcat cylinders and put them on my 900 bottom end. because of different strokes i have to shim the cylinders(.4mm thicker base gasket will take care of that) (stock 1000 stroke:64.6; stock 900 stroke:65)

I want to then bore those stoke 1000cc cylinders 5mm over to a 86mm. Then i can use Wiseco Wildcat 700 big bore pistons (86mm, and same wrist pin size as my 900 crank) to create 1132cc

Second question: If shaving the head does more or less "strokes it" and i take off 1mm that will equal 1150cc, or 2mm makes a 1167cc. How much can i safely take off of the head

Third question: Is this safe? Or am I an idiot? haha
Fuel is not an issue as I want to run high octane race fuel
Machining cost is not an issue because I get a GREAT professional price (so don't tell me to go buy a big bore kit lol)
Thanx guys!

[scrat600]

Don't take this the wrong way but, you're in WAY over your head! First, shaving the head decreases squish and increases compression. You have to modify the crank to increase or decrease the piston stroke. Second, you may get the cylinders bored cheap but they still need to get plated. Third, you'll get more HP from porting than the big bore. Unless you know an expert at 2 stroke cylinder porting that also costs alot. It's nothing like porting a 4 stroke and has very little to do with smoothing the ports out.

So, go buy a big bore kit and have someone assemble and tune it for you instead of spending tons of cash to make your Tcat slower.

[ac900tc]

Shaving heads does NOT increase stroke. The only way to increase stroke is to use a different crank with a longer stroke. Stroke is built into a crankshaft when it is designed. It is the amount of crank "throw" from the centerline of the shaft to the centerline of the rod journal X 2. So it is the measurement the piston strokes up and down in the cylinder. Since a 1000 crank has less stroke than the 900 crank, If you used 1000 cylinders and pistons on a 900 crank you have to use spacers underneath the cylinders. If you did not use these spacers the pistons would not come all the way to the top of the cylinders. This is why some use the 700 piston (they are taller from the wrist pin to the piston head) Thus the spacers are not needed. Brad

[1000 thunder]

I'v been looking into doing this very thing,but the problem that keeps arising is that the stock porting just sucks.If your looking at having a big triple that will get up and move you are way ahead to go with after market cylinders like hooper predator single exaust port,exaust,ect,ect. In the end very costly.

[hickatvracer17]

well first, the porting, honing, boring, head shaving, and plating is all done by the same company that gives me more than 50% off. so its not expensive at all, i already got quoted for under $1000 with the piston kit, because i get the piston kit as cost. there is no way im going to be able to go out and buy a kit for the price i can make it.

second like i said the company that is doing everything, sends it out to get ported, so i dont have to worry about that...

third if you read my post, you will see that i know my cylinders will have to be spaced, hense the thicker base gasket that i can get custom made and/or spacer plate

fourth, i would love to go the easy route and buy hooper, but compare $1000 to $7000. see where im coming from?

fifth, im aware that shaving the heads decreases squish, but i didnt know if it was kind of the same thing, because if you lengthen the stroke, your getting the piston closer the the head. i didnt know if there was kind of a similarity. and i know how stroking works.

basically all i wanted to know is if the 1000 bored cylinders, with big bore wildcat pistons is logical on my 900 bottom end.
(mind you the 1000 cylinders will be bored, plated, honed, and ported [FOR CHEAP])

[bedrock007]

 Quote: Originally Posted by hickatvracer17

well first, the porting, honing, boring, head shaving, and plating is all done by the same company that gives me more than 50% off. so its not expensive at all, i already got quoted for under $1000 with the piston kit, because i get the piston kit as cost. there is no way im going to be able to go out and buy a kit for the price i can make it.

second like i said the company that is doing everything, sends it out to get ported, so i dont have to worry about that...

third if you read my post, you will see that i know my cylinders will have to be spaced, hense the thicker base gasket that i can get custom made and/or spacer plate

fourth, i would love to go the easy route and buy hooper, but compare $1000 to $7000. see where im coming from?

fifth, im aware that shaving the heads decreases squish, but i didnt know if it was kind of the same thing, because if you lengthen the stroke, your getting the piston closer the the head. i didnt know if there was kind of a similarity. and i know how stroking works.

basically all i wanted to know is if the 1000 bored cylinders, with big bore wildcat pistons is logical on my 900 bottom end.
(mind you the 1000 cylinders will be bored, plated, honed, and ported [FOR CHEAP])

From what I know of this use tigershark pistins for that mod i dont believe the skirts r an issue

[SnowXr]

 Quote: Originally Posted by hickatvracer17

First off. I have a 1995 Tcat 900.

First question: Does shaving a head basically increase stroke? so 1 mm off the head would be equivilant to a plus 1mm crank?

Heres the deal. I want to take stock 1000cc tcat cylinders and put them on my 900 bottom end. because of different strokes i have to shim the cylinders(.4mm thicker base gasket will take care of that) (stock 1000 stroke:64.6; stock 900 stroke:65)

I want to then bore those stoke 1000cc cylinders 5mm over to a 86mm. Then i can use Wiseco Wildcat 700 big bore pistons (86mm, and same wrist pin size as my 900 crank) to create 1132cc

Second question: If shaving the head does more or less "strokes it" and i take off 1mm that will equal 1150cc, or 2mm makes a 1167cc. How much can i safely take off of the head

Third question: Is this safe? Or am I an idiot? haha
Fuel is not an issue as I want to run high octane race fuel
Machining cost is not an issue because I get a GREAT professional price (so don't tell me to go buy a big bore kit lol)
Thanx guys!

If this is all a joke for a laugh, then no, you're not an idiot. If you're serious, then yes. I'm kidding, but you're naive if you think you can pull this off on your own without wasting thousands of dollars and hours along the way.

Have you measured the differances in the t-cat and 86mm pistons? How much do they weigh? How will you balance the rotating assembly and balance shaft? How will you determine your port timing and what is your target peak rpm? There's a LOT to think about here before you can end up with an engine that can run well.

By my estimate, here's a fair breakdown of the work and costs:
boring $150
plating $500
pistons $300
base gasket spacer
$80
porting $400 (that's on the low end for a pro, provided you have known engine and goal)
gaskets and seals
$100
cylinder head work (again, need to have a set of meaurements as a goal) $100
pipes $1000 (because your stock 900 pipes won't let the new engine perform it's best)

And we haven't even gotten to ignition, timing, clutching, and jetting.

Just buy a complete motor, or buy proven parts that work on your 900.

[hickatvracer17]

again.. those are average joe prices
i can get all of the engine work done for under $1000. PORTING, REPLATING, BORING, HONING, MODDING THE HEAD. i already got quoted

i'll say this again. under $1000.
and i already have pipes and a dyno to tune them on if needed. or get a new set built for around $1000 if i need/want to.
build price is not an issue, fine tuning is going to be the only ******.

i know people have put wildcat pistons in 1000 jugs on the 900 bottom. i know a bunch of people have. i think that makes a 1004cc. so i was thinking if people have done that, why not bore it and put big bore wildcat pistons in to build it to the max.

even if i stick with the 1004cc, thats a tried and common setup. porting will be easy, head shaving will be easy..plus its practically the SAME EXACT thing as a stock 1000. 1004 is still better than 895.

[SnowXr]

Well, if you think it's that simple.....carry on.

[jim goddard]

i just put 1000 cylinders on a 900 bottom end no shims wiseco makes a piston that has the right mm pin size and i took off about 18 thousand on my heads piston number is 2403m08100 hope this helps i dont think this is 86 mm but it is pretty close to what you are trying to do with out going broke trying to do it i am in the process of trying to re jet mine right now