Another Homemade Bellhousing Thread...

Basically, I am building my own bellhousing to adapt a Ford Toploader 4spd transmission to my old school SB Chev V8. I can buy one for around $450, but it's a heavy 1/4" thick steel monster, and I prefer building my own lighter parts if i can. I'm not concerned about it not being "SFI certified", as it's just a fun street car and i have no desire to make it legal for the track.

The mock-up began with an old 400 block and an empty transmission case. I am using the alignment bar from my rearend narrowing jig to keep everything straight and true. I spent a couple nights machining some steel pucks to fit in the block's main bearing bores and also the bearing bores in the transmission case. The pucks have an 1.501" hole in the center so that my alignment bar will slide inside everything to keep the engine and transmission bores concentric. I made a ring to center the plate that the transmission will bolt to, and a tube spacer that will set the desired distance between the block and transmission face. I have also made the rear plate that the transmission will bolt to, and have laid out the the flange that will bolt to the block and serve as a pattern for the block plate that will fit behind the flywheel.

I'll snap some pictures in the next day or so. Working in my spare time after hours, I expect it will take me a week or two to get it done. The transmission is getting some special work as well, getting faceplated in 2nd, 3rd, and 4th. I'm adapting an aluminum tailhousing from an SROD overdrive trans to replace the Toploader's stock iron piece to shed some weight. Also machined down the Ford throwout collar so that I can use my existing Chevy hyd throwout bearing.

Here's a pic i took back when i was figuring out a way to faceplate 2nd gear. Nobody makes parts for this, so i cut down some 3rd/4th parts that they do make and adapted them to my 2nd gear...

 

Here's the pattern I made out of 1/4" steel. All the hole locations were laid out, centerpunched, and drilled 3/16" so that the pattern could be transferred to the blank piece of 1/8" that it's laying on, which will be used to make the block protection plate. The steel pucks on the right are the pilot rings and spacer that i mentioned in an earlier post that locate everything in the correct positions for mock-up...



Here's the drawing i used to layout the block bolt pattern...



This is the block plate after it was cut out and drilled. The large hole in the center is for the crank's flywheel flange to stick thru, and the 2 larger holes on the sides are for the locating dowels in the block...



This is the pattern after i drilled it out and cut the center out. It is going to be the forward flange of the bellhousing that bolts to the block, the large hole in the center is necessary to clear the flywheel...



Here's the block plate on a block. The upper "wings" were added as mid-mounting points that will hang the back of the engine at the firewall...



Here's the block plate and flange on a block. The block plate will be sandwiched between the block and bellhousing as shown. I'll soon be creating a hole and pocket for the starter.



The mid-mounts incorporated into the block plate allow me to easily remove the bellhousing/clutch/flywheel from the car without needing to support the engine. Greatly simplifies clutch and transmission maintenance.

TBC...

 

Very clean.

 

Very nice work and looks to be well thought out and not just slapped together . Now will your stock bell housing bolt up OK or with there be any spacing problems ? Or is that something you will need to adjust once the engine is put together ?

Retro Jim

 

I like the idea of the seperate block plate for mid mounting, but I'm wondering if a problem might be caused by the block plate and the bellhousing plate sharing the same bolts. I.e when you remove the transmission bolts the block plate will not be attached to the block. I realise the dowels will still be there but will this be enough to stop it moving during removal/installation?

 

Thanks.........I look forward to your progress......I have to build a bell housing for a car with different engine to transmission combination. please keep us posted.
Thanks Steve

 

Weedburner, thats some really nice work dude, way to hit the ground running.

 

Very nice,

My only concern is that you already located the mounting holes and dowell pin locations. This is the can I did for IVO and the Showboat. Since the was never to be run and just static making "true" alignment was not an issue, but what I did notice is that welding it caused the steel to move around a bunch and with the scalloping along the edges will move the metal differently going from thick to thin. Also even though the shop that rolled the band did an awsome job and got it really really close, it still pulled when welded. After it was welded I had to bang on the flange to get it close to flat and then send it out to get it ground to make both sides flat, which is why you always start with thicker material to compensate for this extra work. After all this is done then you locate the dowells and crank centerline.

 

Cool stuff, weedburner. You obviously got skills and you definately got my attention.

How's about an intro? Give us a little background on yourself.

 

" I'm not concerned about it not being "SFI certified", as it's just a fun street car and i have no desire to make it legal for the track. "

According to the pics here, I'd prefer this to anything I've seen commercially available, even with a SFI tag !
Fantastic craftsmanship; Tom S. in Tn.

 

Thanks.
I'm making the bellhousing too, and the depth has been adjusted to work with the block plate.

 

The front of the engine is on a set of Sprint Car engine plates, so it won't move much during maintenance. The dowels stick out longer too, but even if it did somehow come loose, the crankshaft is still sticking thru the midplate's center hole, so it couldn't fall too far.

Here's a pic of the front motor plates, and you can see above the starter the mounting point on the firewall. In this pic the stock cast aluminum bellhousing is in place, and seperate brackets are used to go between the firewall and bellhousing mounting bolts. As it is, the midmount has to be removed to remove the bell, so that's something that i wanted to change with the new setup.



I don't even own an on-topic car, but most of the things i make are made in a traditional fashion with my own hands, so i figure it might be Ok to share with you guys as long as i don't try to show too much of the OT car stuff.

 

Thanks. I realised after I posted that the front mount would have a lot to do with possible engine movement. I wasn't sure if the 1/8th plate would flex enough for the engine to pop off the dowels if the trans was reluctant to move in or out and banged into the plate. Now that I think about it more, studs could be used instead of bolts, depending on clearance.

Can't wait to see the final product.

 

You could also do it just like Weedburner did, and then center the tranny side of the bell to the centerline, right?

 

Hey I sat in the original Showboat when i was a kid, i've even got a big picture of it hanging front and center above my fireplace. I'll never forget it. That one experience was huge in helping me decide what direction i wanted to go later in life. Never did get to meet Ivo, but he was a big influence on me. I even built a dual engine dirt latemodel back in the '90s, likely because of him. I'm a big fan of multi engine cars

I'm going about it a bit different. I'm using an alignment bar in the block's main bearing bores and in the main bores of a dummy transmission case to keep it close to concentric, and a spacer between the block and face of the transmission to set the distance. The block plate and bell flange will be bolted to the block, and the plate that the transmission will be bolted to will be bolted to the front of the trans. Then the rolled ring and starter pocket fab, followed by fabbing some 1/8" square-to-round sheetmetal to mate the ring to the trans plate. After all the fabbing is done and tacked together, it will be welded in place (bolted to the block) as much as possible, with the exception of the trans plate. After everything else is finish welded, then the tacks on the trans plate will be cut and it's location adjusted before it's welded. The final welding of the trans plate will be done around the outside with the alignment bar, pilot rings, and dummy trans case all in place, so i expect it's going to be pretty close. If there is a problem, it's all made of steel, so any corrections that might be necessary would be pretty straight forward.

 

You the guy with the Mazda RX car? Thought about going the used/E-Bay route, as the SBC to Ford manual trans pattern scattershields are/were made? You could still make your own mounting supports. Not trying to discourage you at all, but why re-invent the wheel? Your fabrication skills are right at the top, I wish I had that ability. As far as the metal moving with welding, there are commercially available,adjustable, alignment dowels made by McLeod/Lakewood/et all. Keep everyone posted, and welcome to JJ/the HAMB. Butch/56sedandelivery.

 

Thanks Butch. Yea, i'm the RX-7 guy.
The ready-made bells are pretty heavy. If i modify one it loses it's cert anyway, so i figured i would make my own just the way I want it.

 

I welded the rolled ring to the bell flange today, all the holes still line up...



When i made the parts, all the holes were drilled to the same size as the bolts that go thru them. My thinking was that it would keep everything as precision as possible during fab. After i'm done with all the welding, i'll drill them out one size over to allow easier/quicker assembly, maybe 2 sizes over if i decide to powdercoat it.

 

Here's a few more.

Here's the alignment bar in place in the block, as well as the spacer that sets the depth between the block and trans case...



Here's the trans case in position located by the pilot rings...

 

Wow you've obviously put a LOT of thought into this. I'm interested to see how it turns out.

 

ill second this.

looks good man.

 

subscribed dude!

 

Thanks for the comments guys.

Here's some more...

I had to take it out of the fixture to make sure i had created enough room to install a SoftLoc clutch, so i figured i'd snap a few pics of the progress.

I started making patterns for closing in the bell by laying out the the top section on posterboard. I quickly realized it was much easier to just cut out slightly larger pieces of posterboard, hold them in place on the bell, and simply apply a little pressure by running my finger around the edges of the steel. This puts a small crease in the posterboard and transfers the exact shape needed, a much quicker way to create a pattern...



The transmission plate is still only tacked in 4 places. After all the rest of the welding is done, i'll put the bell back into the fixture, cut the tacks, and re-position the plate for the best alignment possible before welding it in place. I doubt there will be any need to machine the block or transmission mating surfaces.



Still need to make a pocket for the mini-starter that's going on the car...

 

Man thats some well thought out work and nice fabrication. Cant wait to see more progress.

 

Here's the starter pocket addition...





Here's the finished product...







Now i have to finish the transmission before i can swap it into the car...

 

Very well struck, sir.

 

Well done.

 

Very, VERY nice!

 

well shit, dont tell this guy it cant be done!

dam sweet

 

Very cool! Hydraulic T/O I assume? Forgive my ignorance, but wont you need an access port to bleed it?