Topic: Oh dear ...

[grcamna2]

Looks better. 

[PeWe]

Looks better. 

Very weld...

[HondaMan]

Nice save!

The ones I struggle with are the bent ones. These seem to happen more on the K4 and later ones: they are more brittle toward being coaxed back to 'straight', while the earlier ones seem to break off at the initial impact. While (high) heat helps, it also burns fingers(!)

[BenelliSEI]

Nice work! Not easy!

[69cb750]

An older guy in my area has been welding aluminum 50+ years, does a great job, many difficult repairs through the years.
Mr. Bowers welds, I file and shape cylinder to original.

[BenelliSEI]

Funny how it’s always an “old guy”! That’s who repaired mine too……

[PeWe]

You, we all are old guys wrenching with old Honda CB750 and similar!

Younger people visiting this forum will tell others about the old guys reviving old bikes to fantastic marvels from the past.

Fantastic Four is an old Honda!

[RAFster122s]

Old guys learn secrets and have developed patience...good welding is an additive learning processs and learning to read the metal as it flows while welding is part art part experience. Not all have the patience or talent. There was a welding instructor at the local community college in Sierra Vista who was female and she was a master at welding and could weld anything beautifully and her husband was military ...and that was the only reason they were lucky enough to have such a talented instructor and why she was instructing. Her hubby was equally talented. He left the military not long ago and they both left for jobs utilizing their talents for very big money. Their skills allow them to go anywhere and work and earn very comfortable salaries.

[69cb750]

I bought a 1952 CB750 prototype.
Sandcast cases, cylinders, head.
Died in 62, repairs underway.

[69cb750]

[Stev-o]

I bought a 1952 CB750 prototype.
Sandcast cases, cylinders, head.
Died in 62, repairs underway.

Ha!!  WTH is that bike?  Looks very cool.....

[grcamna2]

First time seeing one of these;a four cylinder.. a "square four" ? 

[Stev-o]

First time seeing one of these;a four cylinder.. a "square four" ? 

Me too!!  WTH??   "Square bore"!!

[Mark1976]

First time seeing one of these;a four cylinder.. a "square four" ? 

Me too!!  WTH??   "Square bore"!!

Ariel square 4.

[MRieck]

First time seeing one of these;a four cylinder.. a "square four" ? 

Me too!!  WTH??   "Square bore"!!

Ariel square 4.

There u go.

[grcamna2]

Do the pistons all rise together ?

[69cb750]

Do the pistons all rise together ?

Same as CB750, two and two, one fires every 180 degree.

[grcamna2]

Do the pistons all rise together ?

Same as CB750, two and two, one fires every 180 degree.

180.. two Up-two Down;front to back? or side to side.. ?
Would you turn it over to make two at TDC in a picture ?

[69cb750]

180.. two Up-two Down, front to back? or side to side.. ?
Would you turn it over to make two at TDC in a picture ?

Front row =1,2
Back row = 3,4
1 and 4 at tdc, 2 and 3 at bdc (same as CB750)
Will post photos during assembly.

[grcamna2]

I see..

[seanbarney41]

2 cranks though, right?  ...and they are geared together spinning opposite directions? or geared to primary shaft with both cranks spinning the same direction?

[69cb750]

2 cranks though, right?  ...and they are geared together spinning opposite directions? or geared to primary shaft with both cranks spinning the same direction?

Two crankshafts, gears, rear crank spins forward and pulls clutch, front crank spins backwards.

[Stev-o]

'Squariel'!

Are you going to do a full restoration of the entire bike?

[RAFster122s]

Wasn't Honda playing with bizarre piston design in NX500 race bike?

[Ichiban 4]

I bought a 1952 CB750 prototype.
Sandcast cases, cylinders, head.
Died in 62, repairs underway.

Hey Guys..I was a little surprised that some of you didn't know what that Square Four was.   Guess I'm dating myself here..but Square Fours were all the rage in So. Cal. back in the 60's [if you could get/afford one].  They were also one of the few production big fours being made
around the 40's through 60's.  Think they went out of production around the early 60's (?)

Mine was a Mark II..1958 model..if memory serves me here.  They had torque up the butt and were seriously fast @ the time.  Remember I
dragged a friend with a '63 Ramcharger with a Hemi engine [one of fastest production muscle cars of the time]..and left him in the dust quite literally.  He wasn't too happy about that..needless to say LOL

There are lots of videos on YouTube about Square Fours..if any are interested.  One is:
 

I sold my Square Four when i went into the Navy in '64..but after I got discharged in the early 70's..I remembered the good qualities of four cylinder bikes.which eventually led me to getting Honda Fours [which were engineered much better..and more reliable than the older 'limey'
bikes of the time..I felt]   The rest is history..as the saying goes..

Thanks for the ride down memory lane guys..

Cheers

Al/Ichi