rebuilding a 85 2.6 xp 235 HP questions

[tfmech]

I just got a 2.6 xp 235 that got a piston ring. I am in the process of tareing it dow right now. I had a few questions that you guys might be able to help me with.

Frist it is standard bore right now before I have it bored is the sleeve plated or chromed or can I just bore it?

Second being a xp it has scalloped pistons are they just stock pistons that the factory scalloped and put a diffrent part number on?

Third it has the 325638/9 heads on it and the one 639 head is damaged can it be repaird? If not does anyone happen to have one around they would like to part with? If not what other head part numbers should I be looking I found a good set of 332544/5s will they work or do I need other ones for the 235?

 

[rolmops]

Think twice before you deal with the 1985 235. Their nickname is two thirsty five They are capable of burning through 50 gallons of fuel in an hour when run at WOT.
The repairs are cheap compared to going out boating with that engine.

 

[SparkieBoat]

WOW WEE. 50 gallons in an hour...that is nuts.
I show the part numbers on an 1985 135 as being 0328327 and 0328326. the starboard head 8327 is still available new, $180

 

[SparkieBoat]

ok I found it, you are in luck. this head is still available new, both your heads are.
the 639 head is only $125 search part number

 

[tfmech]

Think twice before you deal with the 1985 235. Their nickname is two thirsty five They are capable of burning through 50 gallons of fuel in an hour when run at WOT.
The repairs are cheap compared to going out boating with that engine.

I am defiantly not looking for info for rebuilding a 85 235 xp 2 cycle because I am worried about huggin trees, or looking for fuel millage....if it is not apparent I am looking for horse power. I am putting together a t 79 checkmate that is going to to be pretty light with this motor and trying to see how fast I can make it go on a budget. I would go with something newer but I like the old stuff....going to be pulling it to the lake with 70 hiboy F250

 

[tfmech]

ok I found it, you are in luck. this head is still available new, both your heads are.
the 639 head is only $125 search part number

639 heads are still available what site are you looking at??

 

[emdsapmgr]

The stock pistons in that engine were high ring pistons back in the day. NLA. They were just stock pistons cut out on the skirt at the time. When I rebuilt mine, I got 6 big bore .030 over factory pistons (these new ones have the lower top piston ring) and had the skirts cut at a machine shop to exactly match the stock pistons that came out of it. Those 638/639 heads were the highest compression stock heads found on a big bore engine. They were used on the 83-85 2.6 engines. But they first came out on all the 1980 235 engines and were the stock heads up through some time into the 81 model year. So, there are heads around, just hard to find. Bombardier shows the 639 head as being an "active" part number. No stock, but is listed as available for "special order." Contact your dealer. The 638 shows discontinued.-but there are two United States dealers that show one new pc in their stock.

 

[tfmech]

The stock pistons in that engine were high ring pistons back in the day. NLA. They were just stock pistons cut out on the skirt at the time. When I rebuilt mine, I got 6 big bore .030 over factory pistons (these new ones have the lower top piston ring) and had the skirts cut at a machine shop to exactly match the stock pistons that came out of it. Those 638/639 heads were the highest compression stock heads found on a big bore engine. They were used on the 83-85 2.6 engines. But they first came out on all the 1980 235 engines and were the stock heads up through some time into the 81 model year. So, there are heads around, just hard to find. Bombardier shows the 639 head as being an "active" part number. No stock, but is listed as available for "special order." Contact your dealer. The 638 shows discontinued.-but there are two United States dealers that show one new pc in their stock.

Thanks for the info. I can mill the pistons at the shop so that is easy. I was planning on only replacing the one piston being the rest look and check like new. Am I asking for trouble since they are still the high ring pistons? Last thing I need info on is the cylinder bores they are not coated or chromed or anything right? They don't look like it I just want to make sure.

 

[SparkieBoat]

the heads are available on boatsdotnet

 

[SparkieBoat]

put a 0 in front of your part number and google it.
the compatibility list this head as being used from 80-85 on 150, 175, 200 and 235 HP motors.
mostly used in 1980 and 1981. so if you find a 1980 or 81 V-6 there is a good chance they may have these heads on it.

 

[tfmech]

I just orded a head hopefully it shows up so i can get this prodject going. thanks for the info

kris

 

[tfmech]

I have a 81 235 sitting next to it it happens to have the other heads on it though and the same hole nicked. Leads me to another question why are most of the crossflows i look at if they have a hurt cylinder it is most of the time the lower starboard cylinder?

 

[racerone]

A 235 does not chew through 50 gallons an hour !!!!----Not sure where that number comes from.

 

[Faztbullet]

(1) The cylinder liners are cast iron (2) replace all the pistons with the low ring design or you will rebuild it again (3) If the heads are just dinged with no embedded ring pieces(check with magnet) they will be fine and dings will fill in with carbon over time, and it will not cause hot spots.

 

[rolmops]

A 235 does not chew through 50 gallons an hour !!!!----Not sure where that number comes from.

I had one on a 22 foot Islander and it happened several times. But I admit that 30 years ago I was a bit of a speed fiend

 

[racerone]

My Wellcraft Scarab Sport with 2 of the 235 's at full throttle might have used that much fuel.