302 compression ?? External fuel tank??

[Islandmon]

cc's are measured at the top of the plug hole. The 18mm plug hole uses an additional .5 cc over the 14mm plug. The combustion chamber is the same for both heads.

cc's are measured at the top of the plug hole. The 18mm plug hole uses an additional .5 cc over the 14mm plug. The combustion chamber is the same for both heads.

Ahhhh ok , thanks very much for the reply. It's this kind of info that us lesser experienced guys really appreciate. At the risk of highjacking the thread how do you and or others feel about 14mm vs. 18mm plugs other than the cost. One thing I've noticed is that when I check my 302 with with 14mm plugs they are always much drier than the 302 with 18mm plugs. I know there could be a variety of reasons for this but just thought I'd mention it.

Thx !

[krazy karl]

Hone

Do you think we still have enough metal in those sleeves to give it a light hone and new rings over the winter? We might want to think about that

Honing will not remove very much material. More important is to check the clearances between piston and cylinder. I wouldn't want to see anymore than .007" and even that is high. If clearances are excessive new pistons "may" solve the problem as most of the wear will be to the pistons rather than the cylinders. If new pistons don't work then you will have to bore and go oversize or install new sleeves. Montoya has .020 pistons and rings available. Get the generic rings, they are much cheaper but must be filed to fit which is the best way to do it anyway. I don't know if OSY allows an overbore so if you are running that class you might check that before you do it. Rick told me that we are the only country that allows overbores in the Yamato so that is why the parts are so expensive, limited demand.

I redid my 302 last winter and it really starting coming on near the end of the season.

kk

[bill boyes]

Couple of things.
1 NKG no longer makes the 18mm plug. Will be necessary to buy a 14mm head or use 18mm to 14mm adaptors.
2. Stock Yamato and OSY motor rules are the same.
3. As Tim said you may have over heated the motor.
4.Check for piston scuff and inspect the bore.
5.120 psi is about right for compression At one time I had 5 yamato's and they all were 120 psi. guess it depends on your tester and and who you ask.


I have a set of standard 302 sleeves that I will sell.

[blueskyracer]

Couple of things.
1 NKG no longer makes the 18mm plug. Will be necessary to buy a 14mm head or use 18mm to 14mm adaptors.
2. Stock Yamato and OSY motor rules are the same.
3. As Tim said you may have over heated the motor.
4.Check for piston scuff and inspect the bore.
5.120 psi is about right for compression At one time I have 5 yamato's and they all were 120 psi. guess it depends on your tester and and who you ask.


I have a set of standard 302 sleeves that I will sell.

I found out about a two months ago when I ordered some more 18mm plugs that they are no longer avaliable. I wish now I had not sold my last ones. Does anyone make adapters to go to the 14mm from the 18mm. This is for my 80 motor.

[bill boyes]

I bought mine at a Machine Shop in the Los Angeles area. It burned down and then was Rebuilt the owner decided not to make them anymore. Not much demand.
Last time I spoke with TJ he said he had them.
Or I will sell you 2 ea make me an offer.

[Islandmon]

Bill, you have mail.

[sponsonhead]

Right here:

Does anyone make adapters to go to the 14mm from the 18mm. This is for my 80 motor.

http://www.amazon.com/Spark-Plug-Ada.../dp/B002XMU0IK

R-19

[bill boyes]

There you go.
Hint. Some are too long and need to be cut off. The excess metal in the cyl will act as a glow plug and burn a piston. I have seen it happen.

[blueskyracer]

http://www.amazon.com/Spark-Plug-Ada.../dp/B002XMU0IK

R-19

Thats the ticket. Thanks Patrick!!

[bill boyes]

the Champion C53CX (293) and the C55CX(294) work well. the 53 being colder.

[blueskyracer]

Geee with this post I am going to take care of two problems with one stone. I also think that while I am tearing down the 302 I will add the port for an external fuel pump/tank system since it is my Mod motor. Anyone have a good deal on a external fuel tank that will fit on the floor between my feet? I am thinking of using the BTM pump system

[bill boyes]

The OMC 15 pump will fit very nicely. There are casting bosses on the right side of the block. It looks as if they were made for the pump. You will need a manifold and check valve set up and a tank return. Ask Sponsonhead for a print and material list. Fuel tank ask Davey Hemp.

[Aussie Steve]

Geee with this post I am going to take care of two problems with one stone. I also think that while I am tearing down the 302 I will add the port for an external fuel pump/tank system since it is my Mod motor. Anyone have a good deal on a external fuel tank that will fit on the floor between my feet? I am thinking of using the BTM pump system

Yes I was going to make my CMH a floatless carb and add a tank to nice question lol

Steve A

[spud62w]

I can make pretty much any kinda aluminum tank you want. I can even put it on the steering bar if you want. I'm Daves Dad

[me-otch]

Spark Plug Adapters

I just purchased these plug adapters off ebay.
A bit more expensive than the ones Sponsonhead posted,
but still a nice looking set.

http://cgi.ebay.com/ebaymotors/ws/eB...K%3AMEWAX%3AIT