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-   -   B17 crank, b18b block, b16b or custom rods, b18b or custom pistons (https://honda-tech.com/forums/engine-machining-assembly-164/b17-crank-b18b-block-b16b-custom-rods-b18b-custom-pistons-3305927/)

forbiddenera 08-25-2017 11:48 PM

B17 crank, b18b block, b16b or custom rods, b18b or custom pistons
 
B16b rods get it close but it's out the hole a bit? Zealworks says -0.046 piston to deck clearance? Or is that in the hole? If it's in, I can just mill to compensate but it's out? I think it's out though so custom rods or pistons maybe, definitely close though..?

Anyone tried this?

Would result in 10.68:1 compression, 1677cc displacement, a nice 1.75:1 rod/stroke ratio and at 10,000rpm the mean piston speed is only 2200fps..

Basically a destroked b18..there's a full b17 advertised for sale locally for a great price so I'm going to try and snap it up. Might run it as is (but boosted) for a bit but Ive always wondered about this combination.

Have a feeling I'll miss some of the torque..but the power will mostly make up for it..

CandyRedRC46 09-01-2017 07:30 AM

Re: B17 crank, b18b block, b16b or custom rods, b18b or custom pistons
 
-0.046 piston to deck clearance, means that you are out of the hole, milling will only make it worse. You could use B16b rods and custom 28.5mm compression height piston, though I have no clue where you could source B16b rods....

What I would do (pending finding B16b rods for sale), is start with a B20 block and have it CSS'd and bored to 84.5mm. Then use off the shelf high compression b20 pistons. With a 29.59mm comp height and custom 141mm rods you could still have 0.022 of clearance and a 1.73 rod ratio.

If you can actually find B16b rods, then a custom piston with 28.5mm comp height and 0cc dish would be nice.

I really like the idea of b20 block and b17 crank, so you have all the displacement of b18 (1826cc), with the rod ratio on a b16. It would be a really cool engine and with CSS it should handle up to 400whp reliably, if properly built and tuned...

CandyRedRC46 09-01-2017 07:56 AM

Re: B17 crank, b18b block, b16b or custom rods, b18b or custom pistons
 
Another really cool option would be B18c block and crank, plus B16b rods and custom 26mm comp height pistons. You could do a CSS 82mm block and get 1842cc's and a 1.63 rod ratio or sleeve the block, bore to 85mm and get 1980cc's with a 1.63 rod ratio.

That engine would be a fucking blast on paper, though in real world application, I am not sure if I am sold, as fully built Honda engines routinely rev to +9k all day with no issue, so it may not be worth the trouble to rev a little higher on paper, while losing torque everywhere in real life.

Charlie Moua 09-02-2017 06:35 AM

Re: B17 crank, b18b block, b16b or custom rods, b18b or custom pistons
 
that's a more complicated setup that it really needs to be.

If you dead set on using that B17 crank to make the rest work, my route of preference would be:

1) if you have b16 head, take it to CNC machine shop to counterbore/sink the camber for additional clearance
2) custom piston
3) head gasket

I'm not a fan of custom rod because cause of lack of interchangeability and market on reselling should you ever have to and also finding another B17 crank in event of rebuild.

forbiddenera 09-04-2017 03:08 PM

Re: B17 crank, b18b block, b16b or custom rods, b18b or custom pistons
 

Originally Posted by Charlie Moua (Post 51399639)
that's a more complicated setup that it really needs to be.

If you dead set on using that B17 crank to make the rest work, my route of preference would be:

1) if you have b16 head, take it to CNC machine shop to counterbore/sink the camber for additional clearance
2) custom piston
3) head gasket

I'm not a fan of custom rod because cause of lack of interchangeability and market on reselling should you ever have to and also finding another B17 crank in event of rebuild.

The rods wouldn't a one off, I've read at least one company has the 140.8mm rods for this application.

The b20 idea isn't bad. Destroking the b18 (lol everytime I type destroking on my tablet it autocorrects to destroying) came to mind because the racing I want to do (rally) has minimum weight restrictions based on displacement for some classes, I'll have to reread the rule as its been a while since I read it but.. I really didn't want to have to runderstand any ballast in the car except to maybe adjust the f/r weight ratio.

I put a 10% deposit down on the B17 longblock today.

CandyRedRC46 09-05-2017 06:47 AM

Re: B17 crank, b18b block, b16b or custom rods, b18b or custom pistons
 

Originally Posted by forbiddenera (Post 51400975)

The rods wouldn't a one off, I've read at least one company has the 140.8mm rods for this application.

Where are you seeing those for sale?

forbiddenera 09-07-2017 02:11 AM

Re: B17 crank, b18b block, b16b or custom rods, b18b or custom pistons
 

Originally Posted by CandyRedRC46 (Post 51401558)
Where are you seeing those for sale?

It was posted on a thread here somewhere..I haven't actually looked myself.

Put a deposit on the motor, will have soon!


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