47-55.1 bore spacing

[mick53]

Hi folks, first I have to give a retraction. I had stated that I was getting a 24 port 24 valve cross flow head for my 292. I was looking at an airplane head or something else. The head I'm actually getting is a 12 port 12 valve aluminum cross flow. On one of the "I'm smarter than anybody and your an idiot" forums it was stated that the bore spacing on the head would never work on an I6. Freaked out a little I called Ryan Falconer today and ask him. It's the same. In the process it accrued to me that the I6 and the SBC have the same bore spacing. Was this a product of the manufacturing and/or the casting process when they started producing the SBC?

[mr48chev]

Small blocks came years before the late six but evidently the engineers kept the bore spacing.

I'm thinking that someone cut the ends off small block heads To bolt them to a late six back in the 70's. This is one that Rotten Leonard on the Hamb was building

[joedoh]

i have worked in engineering/manufacturing most of my career and I can tell you that derivative designs are really common, I have seen aircraft design engineers take lofts from older aircraft designs and I have personally seen the production line pin locations on trucks 35 years apart line up exactly. it wouldnt surprise me at all if the spacing was the same on purpose, because if it works dont fix it!

[mick53]

I also just noticed that after over 40 years of owning my truck that the 235 is 2" off center to the right?

[1project2many]

Was this a product of the manufacturing and/or the casting process when they started producing the SBC?

GM always seemed to be good at determining where not to spend money reinventing the wheel. They seemed to like the 4.4" cylinder centerline.

Here's a partial list of engine families using 4.4" bore spacing:
Smalblock Chevrolet, 262 through 400 ci
Chevrolet I6 including 235, 250, and 292 ci
GM 60 degree V6 including 2.8l through 3.9l engines

I can tell you that derivative designs are really common

For years it seemed like Ford reinvented the wheel every time they built a new vehicle. Of course it wasn't true, but it just seemed like soo many parts were unlikely to fit without extra work if brought from one carline to another or from one engine to another.

[mr48chev]

Originally Posted by 1project2many

For years it seemed like Ford reinvented the wheel every time they built a new vehicle. Of course it wasn't true, but it just seemed like soo many parts were unlikely to fit without extra work if brought from one carline to another or from one engine to another.

You can never assume that anything on a Ford made after 1960 is going to be The same as as it is on another Ford of the same model. On late 60's early 70's Mustangs we used to joke that we had to know the factory color to get the right parts. If it had this engine it had these brakes, if it had that engine it had those brakes. You had to write down the vin when you went for parts.

Chevy = All of a certain year and model had the same stuff or the HD package had bigger stuff.

[_Ogre]

Originally Posted by 1project2many

For years it seemed like Ford reinvented the wheel every time they built a new vehicle. Of course it wasn't true, but it just seemed like soo many parts were unlikely to fit without extra work if brought from one carline to another or from one engine to another.

Originally Posted by mr48chev

You can never assume that anything on a Ford made after 1960 is going to be The same as as it is on another Ford of the same model. On late 60's early 70's Mustangs we used to joke that we had to know the factory color to get the right parts. If it had this engine it had these brakes, if it had that engine it had those brakes. You had to write down the vin when you went for parts.

i always said if you needed a junk yard motor for your red 64 ford car, make sure you find a red 64 ford to pull the motor out of.
i won a 64 for wagon in a poker game, i had no use for it and sold it to a friend that needed a motor for his ford van. he pulled both motors before figuring out the motor wouldn't fit. luckily he was able to sell everything to recoup his money

[_Ogre]

Originally Posted by 1project2many

GM always seemed to be good at determining where not to spend money reinventing the wheel. They seemed to like the 4.4" cylinder centerline.

Here's a partial list of engine families using 4.4" bore spacing:
Smalblock Chevrolet, 262 through 400 ci
Chevrolet I6 including 235, 250, and 292 ci
GM 60 degree V6 including 2.8l through 3.9l engines

interesting, gm also liked to keep bellhousing patterns the same
i believe the new sbc will bolt up to the old belhousings with the exception of the top bolt
not gm but the aftermarket also makes the sbc 454

[mr48chev]

I'm just thinking that I might have to make a road trip to hear Mick's engine run some day. I've wanted to do a road trip to Indiana anyhow.

[mick53]

Originally Posted by mr48chev

I'm just thinking that I might have to make a road trip to hear Mick's engine run some day. I've wanted to do a road trip to Indiana anyhow.

My new head shipped. Should have it Monday.

[1project2many]

Originally Posted by mick53

My new head shipped. Should have it Monday.

I am enjoying your truck build. Can't wait to hear it running.