K-series Crankshaft: Race Preparation by Castillo's Crankshaft Service
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K-series Crankshaft: Race Preparation by Castillo's Crankshaft Service
This is a brand new RSX-S, K20A2 86mm forged crankshaft. We have two of these being prepped by Castillo's Crankshaft Service in La Mirada, CA. They are Southern California's premier specialist that performs top quality work that is proven on the track. They have many professional race teams that entrust their cranks to both Joe and Rudy. More aptly, they have produced cranks that have powered many of the top Sport Compact drag race engine programs. I won't mention specific names, but trust me - you know about them as they're all winners and record setters in their respective classes.
My intent is to expand the quality of information for the community. If you like what you see, please do more research and work with the people that provides you with the benefit and value you seek. Now for the good stuff....
This next set of pics depicts the work in progress for an 86mm crank that will be stroked to 88mm. It will also have the rod journals widened to 0.948" to accept the 5.572" Cunningham Ti rods that have the F20/22C/H-series big end width (0.938"). There is plenty of material in the forged crank, but the key to making it work is proper machining. First stage is knife edging and drilling out the oil plugs. This alone has saved nearly 5lbs off the crank. It will get shot-peened and balanced with the rods and pistons prior to final nitride coating.
We'll also have blank forgings ground to this and any other specification we wish to experiment with. However, since they are still quite a ways off - we are enlisting the quality service of Castillo's since they have a ton of proven experience re-working Honda cranks to prototype and establish some good power figures on the dyno and at the track. They will also grind our blank forgings in the near future. Again, this is all laying foundation to demonstrate the prowess of a fully-built K-series engine - from oil pan to valve cover: crank, rods, pistons and cams breathing freely through ITB's and optimized exhaust system.
Knife edging: first stage of race prep
As you can see, work in progress is moving quite well. Hopefully our pistons will be done this week.
-Ron
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Weight savings so far...
Just got back from Castillo's to drop off another crank. While I was there we took some weights:
stock crank weighs 38lbs
In its current state, the modified crank is at 34.5lbs prior to opening up the rod journal width and final balance.
-Ron
stock crank weighs 38lbs
In its current state, the modified crank is at 34.5lbs prior to opening up the rod journal width and final balance.
-Ron
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Joined: Mar 2003
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Re: (LG_R32)
This particular crank is also getting stroked to 88mm, up from 86mm stock. It will be paired up with the Cunningham Ti rods which are 0.100" longer than stock. Lastly, we are having custom 90mm CP's x-forgings made with a raised wristpin in 12.5:1cr. Final displacement will be a nice 2240cc. It'll get some ITB's and custom header. This will be one motor we'll be testing our cams with.
https://honda-tech.com/zerothread?id=1188287
CP X-forging similar to these:
https://honda-tech.com/zerothread?id=1188897
-Ron
https://honda-tech.com/zerothread?id=1188287
CP X-forging similar to these:
https://honda-tech.com/zerothread?id=1188897
-Ron
HT White Ops
Joined: Apr 2004
Posts: 13,059
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From: Rochester, MN, US
Re: (zombie247)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by zombie247 »</TD></TR><TR><TD CLASS="quote">What does "knifing" do? Makes it lighter so that it may spin faster?</TD></TR></TABLE>
Reduces rotational mass to improve acceleration and reduces windage as well.
Reduces rotational mass to improve acceleration and reduces windage as well.
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Re: (rochesterricer)
rochester got to that before I could... just remember if you go aggro on the crank, better have some ultralite rods and pistons to go with it for best results. Stock counterweights on the crank expect a certain rod/piston mass. There isn't a perfect ratio or rule that I'm aware of, but try to keep everything matched as best as possible and balance to the .00000000000001 gram ahaha.
-Ron
-Ron
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From: Deceptive, CA 805, Jerry Built NA.
Re: K-series Crankshaft: Race Preparation by Castillo's Crankshaft Service (edo)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by edo »</TD></TR><TR><TD CLASS="quote">
This next set of pics depicts the work in progress for an 86mm crank that will be stroked to 88mm. It will also have the rod journals widened to 0.948" to accept the 5.572" Cunningham Ti rods that have the F20/22C/H-series big end width (0.938"). There is plenty of material in the forged crank, but the key to making it work is proper machining. First stage is knife edging and drilling out the oil plugs. This alone has saved nearly 5lbs off the crank. It will get shot-peened and balanced with the rods and pistons prior to final nitride coating.
</TD></TR></TABLE>
This is what I wil do next when I go crazier on my build, or if I lose which ever comes first
This next set of pics depicts the work in progress for an 86mm crank that will be stroked to 88mm. It will also have the rod journals widened to 0.948" to accept the 5.572" Cunningham Ti rods that have the F20/22C/H-series big end width (0.938"). There is plenty of material in the forged crank, but the key to making it work is proper machining. First stage is knife edging and drilling out the oil plugs. This alone has saved nearly 5lbs off the crank. It will get shot-peened and balanced with the rods and pistons prior to final nitride coating.
</TD></TR></TABLE>
This is what I wil do next when I go crazier on my build, or if I lose which ever comes first
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Joined: Jan 2003
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From: So Cal
If just for a brief moment i want to expand on the 'knife edged crank' theories.
This engine is being built by a very capable builder (and machinist it looks like), but there is alot of very hard work that goes into this process. Like edo was saying, the counter weight expects a certain rod/piston weight on the other end, and without very careful machining, the entire balance could be thrown very very far off. This isnt a job for the average street car looking for a few ponies. Best left to race cars, though i know im going to get a few hard-asses coming out of the woodwork for this one.
Its also common knowledge that a 'knife edged crank' reduces parasitic drag, but how exactly? And dont just say 'because its lighter, dummy.' I already know the answer, i just want to see who else is thinking here!
This engine is being built by a very capable builder (and machinist it looks like), but there is alot of very hard work that goes into this process. Like edo was saying, the counter weight expects a certain rod/piston weight on the other end, and without very careful machining, the entire balance could be thrown very very far off. This isnt a job for the average street car looking for a few ponies. Best left to race cars, though i know im going to get a few hard-asses coming out of the woodwork for this one.
Its also common knowledge that a 'knife edged crank' reduces parasitic drag, but how exactly? And dont just say 'because its lighter, dummy.' I already know the answer, i just want to see who else is thinking here!
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Joined: Jan 2003
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From: So Cal
Ok ricer, you got me on that one. Its hard to type down what im thinking on this one...
In terms of a crankshaft, how would lightening it improve power? (The answer does lie within less mass to spin... its quite simple, and i know you know it even if youre not thinking it, im just trying to help teach some people that may be wondering.)
In terms of a crankshaft, how would lightening it improve power? (The answer does lie within less mass to spin... its quite simple, and i know you know it even if youre not thinking it, im just trying to help teach some people that may be wondering.)
HT White Ops
Joined: Apr 2004
Posts: 13,059
Likes: 33
From: Rochester, MN, US
Re: (LsVtec92Hatch)
There are two ways that it makes a car faster; one by improving horsepower, the other by improving engine acceleration(which won't show up on a dyno unless it is an inertial dyno like a Dynojet):
1. It increases hp by reducing the windage losses in the crankcase. The knife-like edge allows the crank to cut through the air and oil cloud in the crankcase with greater ease.
2. It reduces rotational mass, allowing the engine to accelerate faster. Everyone look at the pictures and make note of where the most material is taken off. Due to leverage, the greatest rotational improvements will be from removing mass that is furthest away from the centerline of the crank.
There you go.
1. It increases hp by reducing the windage losses in the crankcase. The knife-like edge allows the crank to cut through the air and oil cloud in the crankcase with greater ease.
2. It reduces rotational mass, allowing the engine to accelerate faster. Everyone look at the pictures and make note of where the most material is taken off. Due to leverage, the greatest rotational improvements will be from removing mass that is furthest away from the centerline of the crank.
There you go.