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[Pan1]

For those that might have checked, how far down in the cylinders are the pistons at TDC. Has anyone milled the cylinders to bring the pistons close to zero deck height?

[prodrag1320]

you really need to check with your cylinders & pistons,dont go by what others have found as it will vary.we machine cylinders all the time to set 0 deck height

[Pan1]

Thank you

[Pan1]

Are the dowl pins easy to remove for cylinder surfacing?

[GMR-PERFORMANCE]

Yes they are , some will remove from the base others from top.

However I did a bit of testing a few years back on the " zero deck" and there is no gains to be had that you can read on a chassis dyno. we had a 107 engine that was 8 in the hole. so based on that spec we tuned it then alter the deck height adjusted the CC volume to have the same static re tested. Tune did not need any adjustment and power remained the same..

For a pump gas street engine its not going to make a difference . Now a drag racing engine that is a full effort sure the flame propagation and comp ratio etc etc all play a role to a much larger extent. Not so much for your every day rider. Thats is my opinion any ways

[Durwood]

Are the dowl pins easy to remove for cylinder surfacing?

I would have them trimmed off the bottom, after measuring and determining how much to remove.

[GMR-PERFORMANCE]

the only issue with removal from bottom is a company that does it correctly.. I have seen the liner cut due to the bore not being 100% concentric with OD of spigot . As that is the norm  Meaning that the bore and spigot do not follow the same measurement.  So they end up cutting into the liner which is not a good idea in my opinion. Now a shop that checks both would see that " hey I need to measure it from here not there" type of deal.  But when you see the spigot fail due to the cylinder being cut incorrectly . and you know that the " in the hole deal is not as big of a deal as the net makes it out to be '  well costly project to do over .

[Pan1]

Thank for the informative information. Sounds like in the hole vs zero isn't going to worth the trouble

[GMR-PERFORMANCE]

well it can be useful but many more questions need to be asked.. some times its a ping issue but then what is the rest of the build. ?? 

[Durwood]

Thank for the informative information. Sounds like in the hole vs zero isn't going to worth the trouble

Hello Pan1, have you measured your deck height to see where it is now?

I personally believe that setting "net squish" is an important part of blueprinting an engine build, and has slowly faded from most builders check list.

For instance, the last build I did the rear was in the hole .010 and the front was .014, if I hadn't corrected the issue, this engine would have not met it's potential, power wise and would have been a ping monster.

Point being, I check them all and correct as needed.

[Pan1]

How does the reduced squish area cause pinging?

[Durwood]

How does the reduced squish area cause pinging?

A reduced squish band, (I shoot for .030"), helps to reduce ping, not cause it.
hi
Basically a properly set "net squish" measurement reduces pinging by increasing turbulence in the combustion chamber, helping to atomize the fuel charge for a more complete burn.

Attention to every detail is what separates a great build from an average one.




 

[Pan1]

I just ordered the 117 kit and plan on using the SE 585 cam instead of the 259e. I have also ordered Cometic .030 head gaskets. My bike is a CVO RG and although I ran the 259e in another CVO and liked it, I want a little more down low torque. I appreciate the answer on deck height.

[Texas 103]

I just ordered the 117 kit and plan on using the SE 585 cam instead of the 259e. I have also ordered Cometic .030 head gaskets. My bike is a CVO RG and although I ran the 259e in another CVO and liked it, I want a little more down low torque. I appreciate the answer on deck height.

 X-2 on the deck education. Thanks.  I am with you on the SE 585 cams for my 117 build coming up. Going to also shave the heads about .020 . Looking to get 10.5 static.   My goal is 125 square.   Make sure if you have a twin cooled you get head gaskets for that. They are different. Have the corect # at the house if you'd like it..   

[Pan1]

It is a wet head. I didn't see gaskets for it on their web site so I called them. I ordered C10086-030. They told me they also make a .040 and a .027