Author Topic: 1/3rd scale V10  (Read 249073 times)

Online steamer

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Re: 1/3rd scale V10
« Reply #15 on: January 12, 2014, 07:17:34 AM »
Here's the manual for a Kempsmith dividing head....it's 22MB...so open it carefully.

See if it matches......

http://www.vintagemachinery.org/pubs/2107/5797.pdf

Dave
"Mister M'Andrew, don't you think steam spoils romance at sea?"
Damned ijjit!

Offline keith5700

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Re: 1/3rd scale V10
« Reply #16 on: January 12, 2014, 08:10:52 AM »
Mike, my references for designing stuff is just to keep plodding away looking at pics, and reading stuff on forums. Most things are designed from scratch these days, but I do a lot of image Googling, looking for pretty things to copy.

Hi George, the line boring was done with the boring bar running in the end two end bearings of the block.
I made the cutter from 1/8 carbide rod, and it had an m3 grub screw behind it to feed the cut in.
I did a reference cut, then dismantled it all, measured the bores and then calculated the amount to turn the grub screw to get the finished bore. Amazingly it actually worked, giving a 1 thou clearance on the crank diameters.

Dave, yes, Kempsmith dividing head. Thanks for that, identified at last.

Offline mikemill

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Re: 1/3rd scale V10
« Reply #17 on: January 12, 2014, 12:20:38 PM »
Keith

The reason I asked about references was because I started a 1/4 scale Coswoth DFV V8 some years ago with only basic info bore, and stroke and limited CAD skills. I worked on the principle of make crank, rods, and pistons then create a block around known measurements. Then decided to dummy a block in MDF but got thoroughly confused, so put all to one side until I could as you say get your head around the problems. So the beast sits on the corner of the bench and looks at me wondering if it will ever be finished!!  As my CAD skills have improved, your thread is encouraging me to resurrect the project. Here are a few pics of how far I got.

Mike

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Re: 1/3rd scale V10
« Reply #18 on: January 12, 2014, 01:30:24 PM »
Beautiful work Mike!

Dave
"Mister M'Andrew, don't you think steam spoils romance at sea?"
Damned ijjit!

Offline keith5700

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Re: 1/3rd scale V10
« Reply #19 on: January 12, 2014, 01:37:44 PM »
Mike, there doesn't appear to be anything wrong with your machining skills anyway, so that's a good start.
On the v8 I scaled down the small block Chevy to begin with, but it soon became apparent it wasn't going to work well, with the type of cylinder liners I wanted to use, so the bore centres are larger than scale, and the piston diameters are smaller, etc.

Your pistons are very close to each other, so in my opinion you'll have to use thin wall steel liners and machine out the whole of the block around the liners, so they are virtually touching each other. Then you'll need a top deck plate to seal it all off.

The 4 valve arrangement will be tricky too, but should be doable.

If you PM me your email I can send over a few PDFs of my v8 block if you like. It may give you some ideas you can use.

Bear in mind, in my case, crank,rods and pistons took up just 6 weeks of a 120 week build. Cheers.

Offline keith5700

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Re: 1/3rd scale V10
« Reply #20 on: January 22, 2014, 10:06:39 PM »
A bit more progress to report. I made the piston rings, using the same extruded (pultruded?) cast iron bar.
I used the non heat method. I'm not sure who's method this is, but I read it somewhere.
After turning and parting off the oversized rings they were mounted in a fixture and a 2 mm cutter ran through to produce the gap.
Then they were closed up in another jig and the outside diameter was turned, to be an exact fit in the bores.
The sides were flattened by fitting the ring into a little holder, and rubbing on some 2500 grade wet and dry paper on a glass flat.
Lastly the gaps were set. I went for 4 thou top ring, and 3 thou for middle and bottom rings.
I may open the top rings up a bit later if I get any form of supercharging on the engine.











I also drilled the block for the water jackets. The liners are double o ringed to seal the water system.







« Last Edit: January 22, 2014, 10:15:27 PM by keith5700 »

Offline b.lindsey

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Re: 1/3rd scale V10
« Reply #21 on: January 23, 2014, 12:36:10 AM »
Man, that's a lot of rings Keith...buts its a lot of pistons and con rods too. I admire you multi cylinder guys a lot for your sheer tenacity :)

Bill

Offline Don1966

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Re: 1/3rd scale V10
« Reply #22 on: January 23, 2014, 01:18:00 AM »
I am awed! That is some incredible work and beautiful craftsmanship. I like........... :ThumbsUp:


Don

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Re: 1/3rd scale V10
« Reply #23 on: January 23, 2014, 02:02:25 AM »
I am going to blatantly steal that cylinder liner design for a project I'm working on!

 :ThumbsUp:


Dave
"Mister M'Andrew, don't you think steam spoils romance at sea?"
Damned ijjit!

Offline keith5700

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Re: 1/3rd scale V10
« Reply #24 on: February 01, 2014, 04:53:56 PM »
Dave, feel free to pinch anything you wish.
Not much to show this week, but I've put a lot of hours in.
The heads have been roughed out and bolted to the block, still in the dividing head.
Most of the head machining will now be done with the dividing head.
First job was to mill out the pockets and bore the valve guide holes.
Instead of screwing the valve guides in as on the v8 I'm going to use a locknut at the top this time.
The threads are M20 x 1.
Ive put a couple of drawings in too, just for interest.
The cam drive will be different this time. I'm going for variable valve timing on the inlet cam. This works by moving the idler pulley which is between the cam pulleys. This will advance the inlet cam by, say, 20 degrees.
The downside is that I need to use seperate belts for each bank, as the left hand bank needs to run anticlockwise, but it should look nice. The gears are 0.7 module helical.










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Re: 1/3rd scale V10
« Reply #25 on: February 01, 2014, 05:40:56 PM »
That looks great Keith.   I like the locknut design.   The cylinder design simplifies the block as well.   I've considered large bore thin section ball bearings for the mains on a V12 project that I'm still sketching up.    But I really like what you've done.    Tell us more about the variable timing... :headscratch:

Dave
"Mister M'Andrew, don't you think steam spoils romance at sea?"
Damned ijjit!

Offline dieselpilot

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Re: 1/3rd scale V10
« Reply #26 on: February 01, 2014, 10:13:49 PM »
Keith, this engine looks great! I don't see how moving that idler located between the cam pulleys will have any effect on cam phasing. You'd have to change the length of belt before and after a cam to change the phasing. It would take an idler before and after the intake cam to change phase. Two are required because the overall length of the belt can't change and you don't want to change exhaust phasing. Some planning is required to get the idlers positioned correctly so as not to change the overall belt length required. I'd guess why you're driving the cams in opposite directions, but I'll simply ask why.

Online steamer

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Re: 1/3rd scale V10
« Reply #27 on: February 01, 2014, 10:49:11 PM »
Diesel,

I "think" he plans to change the timing idler gears before the belts.......I think..... :headscratch:
"Mister M'Andrew, don't you think steam spoils romance at sea?"
Damned ijjit!

Offline keith5700

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Re: 1/3rd scale V10
« Reply #28 on: February 02, 2014, 12:33:36 AM »
I'll get a better drawing of the variable cam stuff up during the week. Basically the centre idler pulley comes down, which advances the inlet cam a bit. There will be some slack on the trailing side of the belt which will be taken up by a spring loaded idler. The centre idler will be hydraulically actuated.
The drawing doesn't show it very well at present.

Thg left side has to be a mirror image of the right bank for this to work properly, which also means it has to rotate the opposite way too. It's work in progress at the moment tho, but it works ok in my head.
There may be a fundamental flaw in the plan yet, but it seems like it should work.
Cheers.

Offline dieselpilot

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Re: 1/3rd scale V10
« Reply #29 on: February 02, 2014, 02:35:55 AM »
I didn't see the spring loaded idler, so you do have two pulleys. I think that is workable. I thought that was why you had the mirrored arrangement and the idler explanation supports that.

Carry on!