V12 Build

[cfellows]

Just came across this thread. That's some nice work. I have a feeling it'll be a bit of a struggle to tame that engine down to a nice idle! Have you decided on a compression ratio?

Chuck

 

[BronxFigs]

Dick...

Just had to ask, but I expected your answer. Thanks for letting us in on the build.


Frank

 

[DickInOhio]

Just came across this thread. That's some nice work. I have a feeling it'll be a bit of a struggle to tame that engine down to a nice idle! Have you decided on a compression ratio?

Chuck

hey Chuck, good to see you here. You know me I like a good idling engine so I'll do what I can to make it work. I haven't settled on a compression ratio. Nothing too high, I don't want it bouncing all over the place. Do you have a favorite compression calculator. I found several online, but they cause me to do a lot of head scratching.

 

[stevehuckss396]

Do you have a favorite compression calculator. I found several online, but they cause me to do a lot of head scratching.

I tried to attach one but the file size is too large. Sorry

 

[DickInOhio]

I tried to attach one but the file size is too large. Sorry

Thanks Steve. Is it one I can find online ?

 

[jdcool4]

This one might work for you http://www.cbperformance.com/v/enginecalc.html

 

[stevehuckss396]

Thanks Steve. Is it one I can find online ?

No its a program I wrote years ago to save myself some time.

PM your email and i'll mail it if you are still interested.

 

[stevehuckss396]

This one might work for you http://www.cbperformance.com/v/enginecalc.html

This one looks nice but it does not factor in the head gasket. In a real motor a gasket change wont make much difference. In engines as small as mine a .010 change in thickness can make big changes.

Peewee with a gasket thickness

.040 = 5.17:1
.030 = 5.49:1
.020 = 5.88:1
.010 = 6.33:1
.000 = 6.87:1

So in a calculator with no gasket and 5.0:1 compression, adding a .030 gasket will lower you to 4.3:1. Thats a pretty big error. Thats why I wrote my own that factors gaskets. I use .030 for head gaskets so thats why i used it in the example. The larger the engine the smaller the error.

 

[jdcool4]

You should be able to add head gasket to the deck height.To get the total height from the top of the pistion to theb mating surface on the head.

 

[cfellows]

I don't really have a calculator. If you know what compression ratio you want, you can subtract 1 from it and divide the result into the stroke to get the head clearance you'll need. For example, if you want a compression ratio of 5:1, divide 4 (5 - 1) into 1.25" (your stroke) which gives you a head clearance of .3125". This will get you pretty close but doesn't consider any openings outside the cylinder walls or in the head.

Chuck

 

[DickInOhio]

I don't really have a calculator. If you know what compression ratio you want, you can subtract 1 from it and divide the result into the stroke to get the head clearance you'll need. For example, if you want a compression ratio of 5:1, divide 4 (5 - 1) into 1.25" (your stroke) which gives you a head clearance of .3125". This will get you pretty close but doesn't consider any openings outside the cylinder walls or in the head.

Chuck

Thanks Chuck. Thats simple enough. Most of the calculators Ive seen ask for a lot more input. 5:1 is about what I was looking for, so guess Im on target.

 

[DickInOhio]

Got a little done this weekend. Ive been working on the uprights or partitions, what ever you want to call them. The sketch below is what Ive settled on.

There are four of these partitions, one on each end and two in the middle. They support the two cylinder plates. The big hole in the middle is for the crank shaft bearings. These are ball bearings. The two smaller holes are for the camshaft bearings. The two rods between the base and the upper partition is .250 drill rod. The crank support is split for mounting the crank and bearings. I'll try to get some photos posted tomorrow.

 

[BronxFigs]

Dick...Will this engine have an open crankcase, i.e. all components visible?


Frank

 

[DickInOhio]

Dick...Will this engine have an open crankcase, i.e. all components visible?


Frank

Yes Frank it will. Much like Randall Cox's Open Six, which I also build some time ago.

 

[BronxFigs]

Then this engine should be yet another interesting design.

frank

 

[DickInOhio]

Starting to take shape.

 

[barnesrickw]

Creative way to form a block.


Sent from my iPad using Model Engines

 

[DickInOhio]

Finished the crank shaft parts this morning. These parts will be pressed in place and pinned.

 

[DickInOhio]

Finished assembling the crankshaft today. It turned out really well, straightest one yet
Next will be the rods i think.

 

[petertha]

Finished assembling the crankshaft today. It turned out really well, straightest one yet
Next will be the rods i think.

That's nice. Can you elaborate on your pinning method. Are they tapered & pressed in with Locktite for example? Did you also have some sort of assembly jig for all the components so they held in position for drilling? The counterweights look black, or is that the lighting?