Drag Specialties 4.250 cylinders

[prodrag1320]

these 124" cylinders are being marketed by a bunch of distributors (drag,tedds,western,ect) ive seen them from everyone but drag,their the same (and im sure drag is too) and who knows where their made,highly doubt japan,tiawan or korea most likely. best bet (IMO) is to go with S&S (or FM if they are actually having their cylinders made by S&S),or just do a 120" build using your HD cylinders with CP pistons

[HD/Wrench]

If I am reading this  right the Fm kit is the same daytona cylinders , ?/  not sure but that is how I read it ?  I have zero issue with the cylinders and they have worked well for us and countless others

these 124" cylinders are being marketed by a bunch of distributors (drag,tedds,western,ect) ive seen them from everyone but drag,their the same (and im sure drag is too) and who knows where their made,highly doubt japan,tiawan or korea most likely. best bet (IMO) is to go with S&S (or FM if they are actually having their cylinders made by S&S),or just do a 120" build using your HD cylinders with CP pistons

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These came from FuelMoto. 4.25 bore. No markings on them other than front and rear

These in the pic are definitely the same cylinder as the Drag/Daytona, the only different marking is the little circle machine mark where the "D" was machined off, and the price I'm guessing.

[Billy]

Just waiting on the heads to come back from FM to finish up this 128.

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[No Cents]

 where did the pistons end up being for deck height?

[Billy]

where did the pistons end up being for deck height?

I measured +.003 (front & rear) with no base gasket, base gasket is .014, head gasket is .030, so that makes the net squish .041.

[No Cents]

  thanks Billy 
What did you think of that paint job on that CVO...it has to be my favorite I've seen so far.

[Billy]

I like it a lot 

[HD/Wrench]

where did the pistons end up being for deck height?

I measured +.003 (front & rear) with no base gasket, base gasket is .014, head gasket is .030, so that makes the net squish .041.

so right at -.018 in the hole .. The numbers will vary  . I would machine those cylinders to zero deck that set up. With increased comp ratio and piston in the hole more prone to detonation has been my experience , it can be tuned out but your leaving power on the table for sure .


I would also add that I plan to measure the cylinder base to liner , IF you look closely at the liner it is not flush with the base of the cylinder , I have not measure it yet with something super accurate just a basic dial caliper but but there is a step down . I do not have an S&S here at this moment but maybe bob can check that .  Not sure why that is either .

[Billy]

where did the pistons end up being for deck height?

I measured +.003 (front & rear) with no base gasket, base gasket is .014, head gasket is .030, so that makes the net squish .041.

so right at -.018 in the hole .. The numbers will vary  . I would machine those cylinders to zero deck that set up. With increased comp ratio and piston in the hole more prone to detonation has been my experience , it can be tuned out but your leaving power on the table for sure .


I would also add that I plan to measure the cylinder base to liner , IF you look closely at the liner it is not flush with the base of the cylinder , I have not measure it yet with something super accurate just a basic dial caliper but but there is a step down . I do not have an S&S here at this moment but maybe bob can check that .  Not sure why that is either .

I'm not sure where you're getting .018 in the hole, the pistons are .003 proud with no base gasket in place, with a .014 base and a .030 hg I get .041 squish. I shoot for .035-.040 squish on a street motor in a bagger with 93 octane readily available.

I'll check the base to liner. Thanks

[HD/Wrench]

Sorry I missed the + on the out of the hole .  I shoot for zero or very close .  What I have seen though is the case height is not standard . Cylinder is but case is not.. I have 3 124 right now in the shop torn down and I used the same cylinder same piston on all 3 . Worst .015 in the hole best .005 HA HA have to love lack of QC  My numbers are with base taken into the equation .

[No Cents]

   jfyi...I did check the cylinders that came with the Fuel Moto 124 kit that Randy is installing on his customers bike.
They did have the machine markings in the center of the slot on top of both cylinders.

[BVHOG]

   jfyi...I did check the cylinders that came with the Fuel Moto 124 kit that Randy is installing on his customers bike.
They did have the machine markings in the center of the slot on top of both cylinders.

Hmm, must be an early kit, or 'that company' in Viola WI is now selling Daytona brand.

[Buglet]

   Being that company is a distributor for the Dayton brand is would assume the sell there parts or maybe there using it on their own bikes.

[alexobelix]

Can those cylinders be used out of the box or do they have to be hohned prior to instal?

Can somebody give further infos for the wiseco pistons that can be used according to the Drag Spec. catalogue (part# 0903-1554) ? They have 11.0:1 compression but what head- and basegasket is assumed for this specification?

THX 

[Nastytls]

Can those cylinders be used out of the box or do they have to be hohned prior to instal?

Can somebody give further infos for the wiseco pistons that can be used according to the Drag Spec. catalogue (part# 0903-1554) ? They have 11.0:1 compression but what head- and basegasket is assumed for this specification?

THX

I was wondering that too. Can you just buy the off the shelf "black edition" 4.250 pistons through Drag and drop them in these cylinders?

[Don D]

Just a general comment as I haven't had my hands on these specific M8 cylinders yet. Cylinders are finished honed to size and pistons have the proper designed in clearance, YMMV. The beauty of the KB forged standard pistons, they are .001 OS or at least many of them are not sure about the M8 versions. A good honing job with plates on a power stroker can always do a better job than a mass production piece. Even with .001 to play with they can be improved IME. Seasoned cylinders better yet.

[BVHOG]

Just a general comment as I haven't had my hands on these specific M8 cylinders yet. Cylinders are finished honed to size and pistons have the proper designed in clearance, YMMV. The beauty of the KB forged standard pistons, they are .001 OS or at least many of them are not sure about the M8 versions. A good honing job with plates on a power stroker can always do a better job than a mass production piece. Even with .001 to play with they can be improved IME. Seasoned cylinders better yet.

There are a couple guys that have the super duty Mil 8 pistons already but they probably won't be done with a production run till June. I have 20 sets on order now.