OzVMX Forum

Marque Remarks => Suzuki => Topic started by: Toolboy on July 29, 2011, 07:44:18 pm

Title: RM370 Piston
Post by: Toolboy on July 29, 2011, 07:44:18 pm

Gday all,

Can you use a RM400 piston in the 370 barrel??

Thanks

Tim

Title: Re: RM370 Piston
Post by: LWC82PE on July 29, 2011, 09:06:57 pm

Rick Horvat in USA has Wiseco RM370 pistons specially made. Well he may not have any left im not sure but just ask him. You may also find his details in an older VMX mag.
[email protected]

Title: Re: RM370 Piston
Post by: lukeb1961 on July 29, 2011, 09:11:32 pm

the RM370 was 77mm*80mm and the RM400 was 80mm bore * 80mm stroke.

Title: Re: RM370 Piston
Post by: VMX247 on July 30, 2011, 10:02:17 am

Quote from: Toolboy on July 29, 2011, 07:44:18 pm

Gday all,
Can you use a RM400 piston in the 370 barrel??
Thanks
Tim

Yes they can
cheers Zook Doc

Title: Re: RM370 Piston
Post by: JohnnyO on July 30, 2011, 11:09:58 am

Yes you can bore the 370 cylinder out and use the '78 400 piston.

Title: Re: RM370 Piston
Post by: Toolboy on July 30, 2011, 01:03:45 pm

What is the difference between a 78 400 piston and a 79/80 Piston???

Is it just the single ring????

Thanks
Tim

Title: Re: RM370 Piston
Post by: VMX247 on July 30, 2011, 06:39:58 pm

 ;D  from your professional Suzuki Doc -  all the RM400's C/N/T use the same piston, it's only the stroke that differs. 400C=402cc 400N/T=417cc 

For clarification, it's only the RM370 that used double ring..all the 400's are the same piston which are single ring.
cheers A & DR
 
 

Title: Re: RM370 Piston
Post by: Toolboy on July 30, 2011, 07:23:27 pm

Ok...thanks for the info..so is there a .75 piston for the 370 or is it easier to get a STD 400 piston??

Cheers

Tim

Title: Re: RM370 Piston
Post by: VMX247 on July 31, 2011, 08:05:29 am

ebay item numbers

220235250144 (RM370 0.75 piston)
190211579004 (RM370 0.75 piston rings)

Search 'RM370 piston' or '12110-41202-075' or '12110-41202' and look for the 0.75 size option.
or
Search 'RM400 piston' and look for the std size.
or
simply google search !!
cheers from your local Suzuki Doc.  ;D

Title: Re: RM370 Piston
Post by: Toolboy on July 31, 2011, 08:28:27 am

Hey Doc,

Thanks for the great info... ;D

You wouldnt also now about sourcing a muffler for the 370???

Cheers

Tim

Title: Re: RM370 Piston
Post by: oldfart on July 31, 2011, 09:21:14 am

MCS  have a universal type that  look OK

Title: Re: RM370 Piston
Post by: Toolboy on July 31, 2011, 12:08:21 pm

Who is MCS??...do you have a link for their web site??

Thanks

Tim

Title: Re: RM370 Piston
Post by: BEARVMX on August 01, 2011, 09:05:03 pm

Gidday same gudgeon pin as rm 400 c/n/t you must use rm370 s/end bearing though, ive just rebored a rm370 cyclinder it fits the rm400 std piston without any problems Bear

Title: Re: RM370 Piston
Post by: VMX247 on August 02, 2011, 09:33:01 am

........RM370 top bearing advice.I believe it's only the N and T models that have a different bearing due to slightly smaller dimensions, the 400C bearing is the exact same part as the RM370. #09263-18011.  ;)  :)
 Out of interest the 400C barrel also bolts straight onto the 370's.  :)
cheers Zook Nuts

Title: Re: RM370 Piston
Post by: Toolboy on August 02, 2011, 04:02:37 pm

VMX... thanks for the info..

I was wondering about the 400c barrel bolting onto the 370.
Do you know if this is the std coversion to the 370 for racing???

Thanks

Tim

Title: Re: RM370 Piston
Post by: JohnnyO on August 02, 2011, 05:51:25 pm

You can bolt the 400C barrel onto the 370 but if someone see's the 400cc writen on the cylinder you won't be able to race it in pre '78.
The 370 cylinder will bore to 400 no problem, i've done it on mine because it's easier to source std 400 pistons than o/s 370 pistons.

Title: Re: RM370 Piston
Post by: oldyzman on August 02, 2011, 08:29:32 pm

Just buy a yz400D....

Title: Re: RM370 Piston
Post by: Toolboy on August 03, 2011, 08:50:35 am

Is the 400 piston 1.0 oversize???

Oldyzman.... I havent noticed the yz400D as they are usually behind me... hahaha

Cheers

Tim

Title: Re: RM370 Piston
Post by: Doc on August 08, 2011, 09:22:35 am

Tim, you would be hypothetically looking at a 3.0mm oversize 370 piston to get to the std 400 bore. An overbore radius of 1.50mm which equates to 3.00mm when measuring the diameter.

Title: Re: RM370 Piston
Post by: Toolboy on August 08, 2011, 06:47:16 pm

Thanks Doc, so is there plenty of meat on the barrel to go out to this speck if required???

Tim

Title: Re: RM370 Piston
Post by: JohnnyO on August 08, 2011, 07:06:51 pm

Quote from: Toolboy on August 08, 2011, 06:47:16 pm

Thanks Doc, so is there plenty of meat on the barrel to go out to this speck if required???

Tim

Yes.. like i said earlier my 370 is bored to 400cc using a std 400 piston

Title: Re: RM370 Piston
Post by: Toolboy on August 09, 2011, 07:39:37 am

Johnny O...did you change the jetting to help keep the piston cool???

Thanks
Tim