I was noticing that some of the B18 Honda Integra engines have a ~5.4" rod that is made from the factory to handle 8,000+ RPMs and 2HP:CI. Since some of the small block race series are using the Honda rod journal size, anyone tried to use an actual Honda rod in a Ford small block stroker? Yeah, I know, it would take a custom crankshaft and piston, but I was thinking a few dollars could be shaved if there was a common application.
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Jan. 28, 2012 12:02 a.m. Canute Reader
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Jan. 28, 2012 12:25 a.m. Knurled Dork
Something to consider... Hondas have tiny little bores in the rage of 82mm give or take. Small block Fords generally have bores in the range of 102-103mm.
Lots more piston weight, in other words. Granted, the stroke is also shorter...
IIRC the only reason the 5.4"; rod is popular for SBFs is because they were sourcing rods from 2.3 engines, which also used a smaller rod journal, so you could offset-grind a crank and have a relatively cheap stroker. When this was popular, getting a SBF to breathe was pretty difficult, so you weren't really going to worry about revving the engine very high anyway.
But now I forget if they were stroking 302 cranks or destroking 351C cranks... maybe I'm thinking of the difference between a 331 and a 347.
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Jan. 28, 2012 12:39 a.m. Sonic Dork
A few more things to consider on top of what Knurled said about bore sizes and piston weights:
The rods in B series Hondas are known as the weak link in the bottom end. FOrtunately, there are H beam rods available that can handle almost anything a Honda motor can throw at them. Secondly, with a Rod/stroke ratio of about 1.58, the piston speeds at 8500+ RPM are approaching the speed of the flame front. The quality of the OEM bearings have a lot to do with their longevity.
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Jan. 28, 2012 3:12 a.m. Canute Reader
Well, with a 331 the stroke is ~3.25", so the R/S is ~1.67. But it sounds as if if one wants that 1.888"-ish rod journal they might as well go with a custom set of rods anyway.
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Jan. 28, 2012 4:55 p.m. Wally SuperDork
Nascar teams have been doing it for years. Smaller Bearing= Less Friction.
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Jan. 28, 2012 6:07 p.m. Knurled Dork
Yes but they aren't using Honda rods, just the journal size.
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Jan. 30, 2012 9:28 p.m. Canute Reader
Knurled wrote:
Yes but they aren't using Honda rods, just the journal size.
Right. I found one place that does that. They have a 35# crankshaft, about 10# less than a Scat lightweight forged crank. It's just that it's $2000.
