about Athena 434cc big bore kit

[hpt1979]

dear all, I've buy a brand new Athena 434cc big bore kit from ebay. Today just begin to install this kit and found that it provided 3 gaskets. One top and 2 bottom gasket in different thickness. I've read the instruction from Athena and it said use the one which is same layer as the stock gasket. So what use is the thin gasket?

Also I found that the stock oil catch tank make me difficult to take off my FCR carb. Any after market oil catch tank is available in the market?

Thank you.

[Rib Eye]

The thicker gasket is the same as the stock gasket on the S model. The e model has a slightly higher compression ratio because of the thinner base gasket. I would use the thinner one myself, but you will be ok with either.

I don't know of any aftermarket oil catch tanks.

[iowaBClivewire]

if you wont full HP gains from the BBkit use the thinner gasket for higher comp ( but you may need to run 91 or better octane to help with detanation )

becouse I like running the cheeper E10 fual I would use the thicker gasket

[hpt1979]

the big bore kit said it have 12.3:1 compression, and mine is a SM model.

which one gasket should I install? In Hong Kong all fuel is 98 octane.

[hpt1979]

Also before big bore I use 175 main jet and 40 slow jet with my FCR40, so what jets should I use now?

[iowaBClivewire]

wow really you have 98 octane ??? that is racing fuel in IOWA

I would run the thinnest gasket in that case

[Roadracer Al]

I'd be cautious about relying on the octane numbers - there are at least two different methods of measuring octane, and they don't get the same numbers.

I'd suggest asking any local shop that modifies vehicles for better performance, and see what they consider a safe compression ratio for your local fuel.

That said, I expect you'll find that the thinner gasket will be fine.

[Julle74]

wow really you have 98 octane ??? that is racing fuel in IOWA

I would run the thinnest gasket in that case

In sweden we have 95 and 98. And 99 in shell stations. Must be another mesurement

[Smias]

In sweden we have 95 and 98. And 99 in shell stations. Must be another mesurement

Greece too .

[stringburner]

From Wikipedia:

The most common type of octane rating worldwide is the Research Octane Number (RON).

There is another type of octane rating, called Motor Octane Number (MON). the MON of a modern gasoline will be about 8 to 10 points lower than the RON.

In most countries (including all of Europe and Australia) the "headline" octane rating, shown on the pump, is the RON, but in the United States, Canada and some other countries the headline number is the average of the RON and the MON, sometimes called the Anti-Knock Index (AKI), Road Octane Number (RdON), Pump Octane Number (PON), or (R+M)/2. Because of the 8 to 10 point difference noted above, the octane shown in the United States is 4 to 5 points lower than the same fuel elsewhere: 87 octane fuel, the "regular" gasoline in the US and Canada, is 91-92 in Europe. However most European pumps deliver 95 (RON) as "regular", equivalent to 90-91 US (R+M)/2, and some even deliver 98 (RON) or 100 (RON)

[Captain Uno]

dear all, I've buy a brand new Athena 434cc big bore kit from ebay. Today just begin to install this kit and found that it provided 3 gaskets. One top and 2 bottom gasket in different thickness. I've read the instruction from Athena and it said use the one which is same layer as the stock gasket. So what use is the thin gasket?

Also I found that the stock oil catch tank make me difficult to take off my FCR carb. Any after market oil catch tank is available in the market?

Thank you.

Use the thinner base gasket if you want the advertised compression of 12.2:1

Do yourself a favor and set the jug on the cases (without any gasket) before you install the piston to make sure the skirt isn't hitting the cases. Athena had a bad batch and it needs to be checked.