Thread: BB build input
11-29-2008, 03:32 PM #1
BB build input
Wondering what everyones thoughts are on building another BB engine. Here's what I'm kicking around: 95mm bore/78mm stroke (555cc) per cylinder, or maybe 92mm bore/82mm stroke (547cc) per cylinder. This will be a 66E based motor. I think the first motor would be a real torque monster but may not want to rev past 7000rpms. The second motor probably wouldn't be as torquey, but would probably rev higher and faster because of the more "square" bore to stroke ratio. Finally, I might just have a 4mm stroke put on a crank, mill some base spacers and run my 87mm cylinders. This motor will ultimately end up in my c/f boat and money is at a slight premium right now. The third motor would more than likely be the easiest and cheapest for me to build....but I don't know which way to go on this.
Motor 1: 1110cc
Motor 2: 1094cc
Motor 3: 978cc
Help me make up my mind.....
I'm also thinking about possibly buying a WDK1200.......
11-29-2008, 05:21 PM #2
I don't think you can go any more than 90 mm on these cylinders - just not enough thickness there to go any larger
11-29-2008, 05:26 PM #3
11-29-2008, 05:35 PM #4
I think you're right on a plated cylinder....but I'm thinking of using the sleeves that Dasa used on my son's 927 (87mm)....they can be opened up quite a bit. I might have to go to WDK billet cylinders to get to 95mm. I'm pretty sure they will take 98mm to get to 1200cc.
12-01-2008, 04:31 PM #5
- Join Date
- Oct 2006
- Plymouth, MA, USA
Mike, keep in mind WDK has issues. Parts, pipe, SUPPORT.
i would do 87mm stroked.
12-01-2008, 04:40 PM #6
send the motor to TJ and have build you a monster.... you won't be disappointed
12-02-2008, 11:49 AM #7
Thanks for the input. I'm leaning towards 87mm bore and 4mm stroked crank (82mm). What should I do about gaskets for the spacer? Use OEM base gaskets one on top of the spacer as well as one below?? Or should I machine the bottom of the cyliner and the top of the spacer and 1211 them like you would two crankcase halves??? Thanks in advance for your replies.
12-02-2008, 04:23 PM #8
Mike call lowell!!!! I wouldn't mill the bottoms as your porting is radical to begin with. Now your changing the timing even more...
12-02-2008, 07:07 PM #9
I'm just referring to cleaning up the mating surface. The spacer plate will raise the entire cylinder up to compensate for the increase in stroke. I will call Lowell and maybe a few other engine builders to get their input before proceeding. I need to get a crankshaft done first. Do you know when I might get your old one???? Not in a big hurry yet....got to get through Christmas first.
12-02-2008, 08:06 PM #10
Mine was an 89mm 5m stroke... Do that combo and some hull mods you will have a 90 mph singlepipe
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