V8

[sprocket1597]

So Ive got no machining expereince, But I would like to build my own engine. I guess the same as everyone else on this forum. I plan to buy a lathe and mill one day in the future. Probably a long way off, with the mortgage kids bills etc. I was thinking with a long time before I actually start on this grand adventure I would design my own V8 to build.

I started with small block chevy dimensions, scaled them down to something I assume will fit under a mill for boring the main and crackshaft journals. I have been takeing insparation from photos of Steve Huck's Little Demon V8. Although I down want to just copy what hes done. Also have been looking at the Whittle and Amsbury plans.

Main objective is to end up with something that runs. Also the idea is to have no parts that need CNC (as I would just have a manual mill to start with). All dimensions are in millimeters, and trying to use parts that are easy to get in Australia. Other than that its a 28mm square bore. And if anyone is interested I will happily produce them.

Heres a work in progress render:

Cheers!

 

[stevehuckss396]

I was once in your shoes. I started out making simple air engines and got more complicated as I went. I always had the V8 dream and it took a mountain of work. Start simple and work your way up and you will "make it happen" one day. Best of luck!

 

[sprocket1597]

Thanks Steve!

I know its going to be a long road! ;D

Cheers
Scott

 

[sprocket1597]

Does the head need cooling? Or is it dependant on displacement of the cylinder?

Cheers

 

[gbritnell]

The head and upper part of the cylinders is where the most heat is made (combustion area) so they could really use some sort of cooling. The block is not as much of a problem as the heads. When a full sized head is made (cast) it has a core that creates a cavity in and around the valve guides, head bolts and combustion chambers to get as much coolant as possible through the head. When you make a model head (without casting) you are limited as to how to get coolant through the head. When I built my 302 heads I did an end view layout of all the shapes in the head, ports, pushrods etc and in the area that was left over I drilled 2 different sized holes through the length of the head. From the head face I drilled the connecting passages.
These engines aren't going to be run for more than 5-10 minutes at a time so whatever cooling you can get will be adequate.
gbritnell

 

[sprocket1597]

Thats what I was thinking, Ive got 5 holes coming up to the head, and I was going to channel it around where I could in the head, with a bolt on cover. a couple of holes running the length of the head does sound alot simpler. The other thing im wondering, would it be better having 5 holes or just one at the end?

 

[sprocket1597]

A little bit more progress....

I balanced the crank based on this: http://modelenginenews.org/etw/etw_bal/p2.html
(Weight of Big end of conrod, Big end bearing, end cap and bolts, plus half the weight of: piston, rings, gudeon pin, small end bearing and small end of conrod.
Am I right in just using the weight of one piston and conrod etc?
I just had a look at Micks Hemi 426 files in the download section and he has used 2 pistons/conrods. Plus an extra weight.

Cheers
Scott