1000 73.5mm overbore kit

[salty_monk]

How can these be so cheap?

http://www.ebay.com/itm/78-81-Suzuki-GS1000-1100cc-Bigbore-Piston-Kits-with-Head-Gasket-GS1000BB-/160808371074?pt=Motorcycles_Parts_Accessories&hash=item2570ed0382&vxp=mtr#ht_1210wt_1163

$140.

Wiseco, JE etc equivalent kit is at least $500...

[Steel Toed Tank]

I would imagine it has to do with the cost of the materials that go into it.

Higher cost materials usual equal higher quality materials.

I bet the profit margin between these and a brand name set are not that far off of each other, but the cost to produce them is!


Tank

[7981GS]

Factory over-bore copies.
Same cast piston design and same low compression ratio.
Probably a good way to gain a little more power.
Especially if you have some 1074 cylinders that HAVE to be bored.

Eric

[SqDancerLynn1]

those look like cast pistons Still a great deal. ?? The valve reliefs don't look very deep

[mawg]

[QUOTE=

Higher cost materials usual equal higher quality materials.
+1 on that.If I could find out what alloy they're made from, weather cast or forged,and how they compared to OEM,I might consider them for a stock rebuild.I'd like to find out more about them before I'd make up my mind.Notice that there's no specs?All this points in the direction of cheap, but not good nor fast.I like to get at least two out of three.

[Nessism]

73.5 mm over bore on a GS1000 leaves the liners really thin. It's doable, but not generally advised.

Those pistons look decent enough. I suspect they would be fine. Cast, just like the OEM Suzuki pistons.

[7981GS]

Factory over-bore copies.
Same cast piston design and same low compression ratio.
Probably a good way to gain a little more power.
Especially if you have some 1074 cylinders that HAVE to be bored.

Eric

Safe bet to use in the 1074 cylinders.
I have been running the MTC forged 73.5 pistons in one of my '79 1000E engines since '93 (?)

I have some 1074 cylinders that are ready to go to replace that set-up with 74 mm MTC pistons on stand-by.



1114 cc's this time around. (IIRC)
That bike, doesn't need any more power, it is starting to leak.

Eric

[CocoTiTs]

And I can't wait to copy your build Eric!!

[1948man]

If you overbored a 1074 to accommodate that set, what displacement would you end up with approx? I have a spare engine that probably needs overbore. Was the 1114cc you mentioned for that scenario?

[7981GS]

1848, IIRC, the 73.5 pistons in to a bored 1074 engine nets 1154 cc's.
In the shorter stroked 997 engines, it nets 1100 cc's.
Perhaps someone else will correct me on those.
I am using the 74 mm pistons in a 1074 cylinder on a 997 block netting the 1114 cc's that I mentioned.

Eric

[1948man]

Wow, 1154 sounds about right, enough to make a difference. About Bandit B-12 size.

[Nessism]

73.5 mm pistons in a GS1000 makes 1100 cc.

[7981GS]

73.5 mm pistons in a GS1000 makes 1100 cc.

And in his 1074?
Does it make the 1154 that I posted? Or is it 1157? Something else? I forget.

Thanks. in advance.

Eric

[1948man]

Looking in the manual, the 1074cc 1100g has a piston diameter of 71.95. The 73.5 mm pistons would be 2.15% larger. 102.15% of 1074cc's is 1097cc. Am I over-simlifying this? The stroke wouldn't change, would it?

[7981GS]

Stroke doesn't change but you gain bore X stroke in cc's.
Example: The 76 mm pistons in my '82 1100G made 1198 cc's.

Eric