Rebuilding this 440-need advise please.

[Steven]

I'm rebuilding my 440EX and I need some advise.

On a side note, kudos, to Ross Pistons! They stock 89.1mm, 89.3mm, and 89.5mm 11.2:1 (withXR400 gaskets) pistons for our EX's for a mere $125.

I will be taking my cylinder to the machine shop for them diagnose the damage on the sleeve so they may recomend how much overbore I need in the piston size. I don't want to purchase a piston then have it not be large enough to replace the scorched metal in the sleeve. Is this the proper way to make the preliminary decision of what oversize piston to use?

This question relates to compression ratio. I have already purchased the gasket set from Cometic. I got the .025 head gasket and the .010 base gasket. This combination will put me closer to a 12:1 compression ratio with the Ross piston. My first concern is octane rating. Will 100 octane Cam2 race gas be sufficient for that amount of compression? I can buy it here for under $4/gallon. Another concern of mine is heat. I fear the 12:1 is going to cook the oil and ruin my new top end. I can't afford and aftermarket oil tank yet. What are your thoughts on this?

I am purchasing new rockers and cam... together this time. I know from my experience with cars that the metalurgy between the cam lobe and rocker arm is important for longevity. The Hotcams Stage II seems to make sense because they apparently match cam metal hardness to that of Honda's OEM rockers by avoiding weldups/regrinds and I understand that they are fresh cores cut to spec. Hotcams are an inexpensive cam in relation to others. Why? Are they a good/reliable cam for sport riding? I don't race.

Last question is on the cylinder head. I am sending the head out for a 3 angle valve job (on serdi machine) and port clean up. As I understand it, the intake valves are junk. Mine are three years old now so'm I'm replaceing them with the OEM ones for the fresh cut. I noticed the exhaust valves are twice as costly, likely due to the better metal thay are made from. Should these be replaced as well or can I just have them re-cut?

I really need some expert advise here. The guys at my local Honda shop are clueless on this stuff.

Thanks!

Steve

first i'd have a new sleeve pressed in. that should keep heat down more. the thiner the cylinder wall the less heat transfer or something like that.

instead of a oil tank have you considered a oil cooler. four stroke tech puts out a nice one for around 125.

[bmw500hp]

[I noticed the exhaust valves are twice as costly, likely due to the better metal thay are made from. Should these be replaced as well or can I just have them re-cut?B][/QUOTE]

In regards to the valves... the exhaust valves take by far the most abuse..money well spent in this area.

why don't you consider an after-market oil cooler...they can be had for around $100.00. A used pingry might might be obtainable for $125/$150.. Most reputable engine builders advise additional cooling with a big bore especially at 12:1 compression. Tinner also has nice looking scoops that may also help... they are much more resonable than over-priced counterparts.

[nakomis0]

You have alot of tech questions.

All I can say is your bike is going to run hot with that compression and bore. The FST cooler would be a smart buy. Extra cooling and extra protection for your cam and rockers.

100 octane for under $4.. im glad I live in the city we get 110 Torco for about that price.

Good luck with the rebuild.

i used to get 110 for 2.30. now the price went up to 3.30

[2qk4u]

i wouldnt use a cometic gasket on my lawn mower. just my 2 cents. get oem

[Steven]

Can anyone construtivley answer my questions?

Thanks...