Author Topic: How do I fully Build a Model 28 flat head?!?? Help plz  (Read 1076 times)

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Offline Hoonigan

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How do I fully Build a Model 28 flat head?!?? Help plz
« on: December 28, 2019, 08:01:30 AM »
So where Im at we have a new class starting in 2020 with is for Fully built Model 28ci Flat heads!! Obviously I need a Flywheel and Starter.... But what next?!?? Any and all info appreciated!



Offline BIG AL 202

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Re: How do I fully Build a Model 28 flat head?!?? Help plz
« Reply #1 on: December 28, 2019, 11:32:29 AM »
The sky is the limit! How far and how much you have to spend is the question.
ALWAYS VOTE FOR ED!   FONGS BROTHER FROM ANOTHER MOTHER!


Offline nic_hayes

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Re: How do I fully Build a Model 28 flat head?!?? Help plz
« Reply #2 on: December 28, 2019, 11:41:02 AM »
Camshaft and a good port job. Get the crankshaft balanced, arc rod. Try to find an 11hp head. Need a worked over carb also.
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Offline Snapper#67

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Re: How do I fully Build a Model 28 flat head?!?? Help plz
« Reply #3 on: December 28, 2019, 12:12:45 PM »
Iíd stay away from the 11hp(25ci) unless youíre able to re-work it and make it flow as much or as good as the 12hp (28ci)head , but once you think you have enough flow, get more, flatheads donít need the compression that OHVís do to make power the need the flow to get the fuel mixture into the cylinder, do some searching on here thereís lots of info on flatheads!
Gotta risk it to get the biscuit!

Offline Snapper#67

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Re: How do I fully Build a Model 28 flat head?!?? Help plz
« Reply #4 on: December 28, 2019, 12:15:06 PM »
Iíd stay away from the 11hp(25ci) unless youíre able to re-work it and make it flow as much or as good as the 12hp (28ci)head , but once you think you have enough flow, get more, flatheads donít need the compression that OHVís do to make power the need the flow to get the fuel mixture into the cylinder, do some searching on here thereís lots of info on flatheads!

Iíll correct myself , get as much flow as possible without opening/hogging out the ports, or youíll ruin your velocity, thereís a fine line, Iím sure other will know more, and chime in, there is a balance, sometimes less is more 😉
Gotta risk it to get the biscuit!

Offline Snapper#67

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Re: How do I fully Build a Model 28 flat head?!?? Help plz
« Reply #5 on: December 28, 2019, 12:57:14 PM »
Word of advice, start with a motor that has the nut on holding the flywheel on that way is is more likely to have the removable eccentrics, to allow brass counterweights, or youíll have to get a machine shop remove the eccentrics from other cracks, saves some work
Gotta risk it to get the biscuit!


Offline Hoonigan

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Re: How do I fully Build a Model 28 flat head?!?? Help plz
« Reply #6 on: December 28, 2019, 03:03:40 PM »
Cost is no Issues, Id like to build it the best way I can, I have no experience building motors always ran stock but know alot of ppl and know I can accomplish what ever is needed, more so looking for someone who may be running a built flathead that could share some infor or tips as well!

Offline PJG56

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Re: How do I fully Build a Model 28 flat head?!?? Help plz
« Reply #7 on: December 29, 2019, 09:03:23 AM »
Cost is no Issues, Id like to build it the best way I can, I have no experience building motors always ran stock but know alot of ppl and know I can accomplish what ever is needed, more so looking for someone who may be running a built flathead that could share some infor or tips as well!

Pm me ,i have all the parts you need to build one,and can help you thru the process correctly
Paul Guptill  (oppy) #238modX
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Offline Negrey

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Re: How do I fully Build a Model 28 flat head?!?? Help plz
« Reply #8 on: January 24, 2020, 04:53:23 PM »
What about valve guides? Is it best to replace them when rebuilding a 28 flathead for racing?
Evan

Offline Snapper#67

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Re: How do I fully Build a Model 28 flat head?!?? Help plz
« Reply #9 on: January 27, 2020, 04:25:36 PM »
What about valve guides? Is it best to replace them when rebuilding a 28 flathead for racing?


Certainly not going to hurt to ensure a proper sealing valve , along with measuring the valves for wear
Gotta risk it to get the biscuit!