Straight 8

[stevehuckss396]

With the Peewee running I have decided to revisit a project that I started 3-1/2 years ago. It is the first attempt at an engine that i ever made. First starting out I thought I was the only one out there doing this. I found out about clubs and NAMES shows and quickly learned how poor a design it was. I am going to attempt to improve some things and see if i can get this thing to fire.

I wanted to build a straight 8 because it would be unlike any of the other engines i saw (replica engines, conley). I was trying to make it look somewhat like the 1932 Bugatti but not quite. I have some of the parts made and some things will need to be remade. One of those things is the cylinder block. The new block will have good cylinder liners and water jackets.

No laughing about me cleaning up between pics. If i didn't, you wouldn't be able to see the parts.

Pic 1 shows the cylinders being drilled. I would have drilled bigger but that is the largest drill i have.

Pic 2 shows the bores. The bores are 3 tiers. The bore will be larger above the water jacket so the liner will drop 3/4 of the way in before pressing.

Pic 3 shows the head bolt holes

Pic 4 shows the water passage holes. There will be 4 passages that will transfer water to the head.

 

[Deanofid]

Great start, Steve. This should be an exciting thread.
Thanks for starting it off with the nice pics!

Dean

 

[hobby]

Good looking job.
Thanks for those pics.

Don't laugh about the cleanup?,
I have my portable shop vac sitting right on my workbench next to my mill, after every couple operations, I sweep up the table, and the workpiece. ;D

 

[Diy89]

Nice! I always had a soft spot for the straight 8. Dad had one in an old pontiac. What a great sound!

 

[cobra428]

Steve,
Very Nice start! Bore? Stroke? Please!

Tony

 

[stevehuckss396]

Steve,
Very Nice start! Bore? Stroke? Please!

Tony

It will be a .850 bore and a 1.062 stroke. That block is 8.250 long. Cylinder bores are 1" on center. 4.823CID

 

[cobra428]

Steve,
Should have nice pizazz. :bow:

Tony

 

[cfellows]

Wow, great project, Steve. I, too, always had a soft spot for straight 8's, especially the old Buick's with overhead valves. Gonna be a great project!

Chuck

 

[NickG]

Wow, never seen a model straight 8! I sense we are in for a treat here! :bow:

 

[CMS]

Off to a good start and hope it turns out as good as the Peewee. But I do have to comment about one thing, and that's the space between the cylinders. Think maybe the head gasket will be a challenge on its own.

 

[stevehuckss396]

Off to a good start and hope it turns out as good as the Peewee. But I do have to comment about one thing, and that's the space between the cylinders. Think maybe the head gasket will be a challenge on its own.

Once the liners are in, there will be well over 1/8 inch between the barrels

 

[gbritnell]

Hi Steve, nice looking start on the block. At times I had thought about doing something like this but I always looked forward to the crankshaft and cringed a little. Maybe someday.
George

 

[kustomkb]

Not wasting any time eh?

That's what we like to see. I look forward to your progress!

 

[SAM in LA]

Off to a good start and hope it turns out as good as the Peewee. But I do have to comment about one thing, and that's the space between the cylinders. Think maybe the head gasket will be a challenge on its own.

You can use a copper "O-ring" around each cylinder as the Head gasket.

SAM

 

[Bill Mc]

Hi Steve - I am so happy to see you describing your build of a straight 8 with lots of photos. I have always admired the Buick and Oldsmobile straight eights of yore. A friend of mine had a 1952 Olds straight 8 OHV with the 'super drive' automatic transmission. It was a real good engine with lots of torque and could outperform my '52 Olds with a V-8 and standard automatic transmission. Good luck on your build and I will be watching as you progress. - Billmc

 

[Lorenz]

That's impressive!

How do you make the crackshaft?
And where is did the crankshaft be supported? because the length off it,

Greetings!

 

[stevehuckss396]

That's impressive!

How do you make the crackshaft?
And where is did the crankshaft be supported? because the length off it,

Greetings!

There is another section that the crankshaft resides in. This section bolts on the top of that piece. The crankshaft is pressed up. It is made fron 17 pieces all pressed and keyed together. If it prooves to be to weak, i will try to turn a one piece and make some shell bearings. (oh boy)

 

[stevehuckss396]

Well I made it thru this one without disaster.

Pic1 is the cutting of the waterjackets. I plunged a .750 key cutter into the bore to desired depth. Then i moved .125 off center and moved in a .250 square staying .125 off center. Does that make sense? Then I moved .175 off center along the X and Y axis both pos and neg. This pattern gave me enough overlap with the cylinder next door that it created a passage between the bores. Water should flow into the side plate thru the entire block and up into the head in 4 places.

Pic 2 the block was rotated 180 degrees and the mounting holes are drilled. These 12 holes are to attach the block to the crankshaft support section.

Pic 3 is the head bolt holes being counterbored. This block has to be bolted to the head before the block is attached to crankshaft support. These counterbores hide the head bolts to make this possible.

Pic 4 shows the block assembled with the lower block/crank support.

 

[SAM in LA]

Very impressive.

 

[stevehuckss396]

Very impressive.

Thanks! Still have some work to do as far as threaded holes for the side plates. I think im going to cnc those. Between both sides there are 76 holes to make and i dont want to misplace one.