'61 Bonneville Bubbletop

[TheMonkey]

project is a '61 Pontiac Bonneville bubbletop.

plan is a ground up restoration with my son who is 14 now. i've done a handful of wrenching, but this will be the first bottoms up project, and the plans are becoming more & more ambitious.

i found a project car that has everything but the engine/tranny/driveline. looks a bit rough, but that's how we wanted it. sort of our own Flight of the Phoenix project.

455 is at the shop now getting the treatment. full blueprint with new eagle H beam rods & dished Wiseco pistons. 72cc E heads will get 10.25:1 CR. this combo is supposed to be good for 93 octane, particularly since i plan on a megasquirt EFI system. i have not decided on cam grind yet, but recon i will end up with hydraulic roller. not too nasty though, because driveability is more important than shaving tenths. maybe XR276HR?

tranny will be 4l80e. i have a TH400 in a '61 Bonneville convertible, and there seems to be loads of room left in the tunnel. i think the fit should not be difficult, except header collectors might be in the way of linkage. as of now, i'm looking at the TCI controller, although by the time i'm tuning, there might be other cool products avail.

rear end will be stock with the huge early pontiac rear end, although i need to upgrade to posi & config the ratio.

not sure about frame mods yet. i'll be visiting a couple restoration shops to discuss body work & any frame changes. biggest tires i could fit in the back of my convert was 245; not terrible, but wide enough? front end geometry is a struggle as it comes stock.

also not sure on the look of the car. i imagine a stance that is mildly lower than stock. i like the look of 17's, but could be talked into 18's. would really like to have a black car with red interior, but jury is still out if the body can be prepped for that. i would like to have a custom dash, but would need to outsource the design, that is out of my league. the 4l80e accepts a paddle shifter, so bring it on.

i imagine the exhaust to be headers into x-overs and through some really big free flowing mufflers. i don't get too excited about loud exhaust.

i do not know how to properly design the combo for cam + torque convertor + rear end ratio. i still need to define exactly my plan for what i want, but like i said, my goal is driveability and be able to put a lot of miles on it with very few of them actually displaying monster acceleration.

i'll post some pics as it sits soon, and you will see exactly how ambitious this is....

welcome any encouragement, and thanks in advance for any help.

cheers,
Scott.

[Ralph LoGrasso]

Welcome to the site, Scott. It sounds like you've got a cool project on your hands, keep us updated.

[Mr.VENGEANCE]

yet another Bonneville!

great im not alone! welcome!

[ProTouring442]

Did Pontiac use the X-frame like Chevrolet? If so, be sure to brace the rear controll arm mounts! I grabbed a nice second gear in my '61 Impala and ripped the right lower right off of the frame. Made for a VERY interesting ride! First time I really learned what "pucker factor" meant!

Shiny Side Up!
Bill
'72 442 "Inamorata"
www.FQuick.com/ProTouring442 (http://www.fquick.com/ProTouring442)

[TheMonkey]

Did Pontiac use the X-frame like Chevrolet? .....

the bonneville frame is full perimeter without the x (if i understand the comparison correctly).

i won't be jamming more torque through than others before me, but i will consider some frame reinforcements & mods while i have the opportunity.

[ProTouring442]

the bonneville frame is full perimeter without the x (if i understand the comparison correctly).

i won't be jamming more torque through than others before me, but i will consider some frame reinforcements & mods while i have the opportunity.

Ok, more like the Oldsmobile then... Kinda wierd that they all used the same body, but different frames then.

Shiny Side Up!
Bill
'72 442 "Inamorata"
www.FQuick.com/ProTouring442 (http://www.FQuick.com/ProTouring442)

[Damn True]

Welcome, but geeeeez, post a pic dude!

My wife and I saw a really nice '60 Bonny at a Goodguys show last weekend. I'd like to see the differences.

[dipren443]

:postpics:

Seriously though, this is probably one of the "prettiest" designs from GM in the 60's. Awesome project, I have been looking for a good project 61 bubbletop for a little bit now...

Oh, and post some pics :)

[TheMonkey]

okay.... use your imagination, because i sure am.

as it sits:

https://static1.pt-content.com/images/noimg.gif


and the following one belongs to a friend in town. this car is also the reason i lusted after a hardtop. i have this in a convertible too, but i really like the bubbletop better. this one is an amazing example. it has the '61 425A tripower with custom paint from the factory. some Pontiac people are going to be upset with what i'm going to do to mine, but i can't wait to get started. :Alchy:

https://static1.pt-content.com/images/noimg.gif

[TheMonkey]

my convertible

https://static1.pt-content.com/images/noimg.gif

[Damn True]

Damn, that IS cool!

I think I'm still partial to the '60, but you got yerself one heck of a nice car there! Can't wait to see it take shape.

[TheMonkey]

Damn, that IS cool!

I think I'm still partial to the '60, but you got yerself one heck of a nice car there! Can't wait to see it take shape.

thanks DT. my wife is pretty anxious to see it take shape too. not all of us are able to see potential....

[6'9"Witha69]

She will see it. It is just a long road sometimes. Welcome to the site. Coll project you have there.

[TheMonkey]

car still at body shop... these just back from machine shop (fuel rails & mpfi provisions on manifold are custom)

https://static1.pt-content.com/images/noimg.gif

https://static1.pt-content.com/images/noimg.gif

[TheMonkey]

finally back from the body shop a couple weeks ago. i'm working on reassembly now. motor is complete, and running MPFI. i'm nibbling on the weekends, so i expect to be rolling next Spring. that leaves me the Winter to tie up details. i have nearly everything ready; interior, bumpers, trim, etc...

i have the 4 link rear suspension replaced with tubular arms and poly bushings installed. still not sure what i'm going to do with the front geometry and caster.

trans will be TKO600 instead of the 4L80E.

pontiac 455 +.030 motor made 527hp 550tq at the dyno through cast exhaust & with carb for break-in. mild idle with 14" vac. cam is HR 230/236/112.

https://static1.pt-content.com/images/noimg.gif

https://static1.pt-content.com/images/noimg.gif


https://static1.pt-content.com/images/noimg.gif

[Rubes]

Sweeeet!!!

[Mr.VENGEANCE]

dont you just love bubbletops..

[Tiger]

love them bubbletops!! lease post more pics as you procede

[BobB66SS]

Nice! My '61 Impala bubble top is at about exactly the same point. Keep the pics coming.

[subtlez28]

Too cool!
I love it!
Nice choice!

Please, keep the build pics coming!

[69LT1Nova]

Dear lord that is going to be one nice car. :twothumbs :drool:

[insane1]

You know, when you said that is was rough, I thought that it was going to be rough. You must not know what some guys are starting with nowdays.

Keep up the good work!

[TheMonkey]

thanks for the compliments, i'll update as things come together.


You know, when you said that is was rough, I thought that it was going to be rough. You must not know what some guys are starting with nowdays...

right... i suppose it's all relative. this was about as rough as i was comfortable working with. i've seen those projects that were pulled out of the river, and it amazes me everytime they come back to life.

[oorange67]

Love your bubbletop I have a 61 olds bubbletop but I have to many projects and don't think I will get to it anytime soon. might have to let it go.

[BossaNova]

https://static1.pt-content.com/images/pt/2008/04/LebronLightningLemonade-1.jpg

[Hammered]

Scott,

Good to see you over here.

John

[TheMonkey]

Hey John!

I ordered the TKO-600 yesterday. Funny how similar our drivetrain will be.

You've probably already been out a couple times since the snow melted?

Scott.

[Hammered]

Absolutely! I was out the first weekend after the salt was washed off the roads. This was a long winter so I'm anxious to get going.

I love the bubbles - I think the '60 is my favorite but I'm liking your '61 a whole lot.

[Zarp51]

Just starting the rebuild on my 61 bubbletop. Bought it in 1982 put a four hundred and a 400 turbo trans in it then, been driving it ever since. Now have a 421 HO tri power and a four speed for it. I paid 125.00 dollars for it when I bought it and it was really nice, no rust and loaded. All there too. It came from the high dessert in southern California near victorville for those who know the area. (I now live in Kansas) It has factory air (complete and intact) power windows, power seats, power steering, power brakes and eight lug wheels. I got all the parts for the clutch linkage from a 1962 Catalina.

[J-440]

Looking good and man I love the trunk space. You could call Rick's Stainless Tanks and put a 50 gallon fuel cell in there with room to spare!! Just curious, did that car come with a flexible driveshaft and transaxle? A guy in Hot Rod built up a wicked Catalina and he said it was a bitch to modify/replace the rear suspension.

[TheMonkey]

Just starting the rebuild on my 61 bubbletop. Bought it in 1982 put a four hundred and a 400 turbo trans in it then, been driving it ever since. Now have a 421 HO tri power and a four speed for it. I paid 125.00 dollars for it when I bought it and it was really nice, no rust and loaded. All there too. It came from the high dessert in southern California near victorville for those who know the area. (I now live in Kansas) It has factory air (complete and intact) power windows, power seats, power steering, power brakes and eight lug wheels. I got all the parts for the clutch linkage from a 1962 Catalina.

Sounds great, good luck with new motor - would love to see pics! Thanks for bringing up this post, i'll update pics below.


Looking good and man I love the trunk space. You could call Rick's Stainless Tanks and put a 50 gallon fuel cell in there with room to spare!! Just curious, did that car come with a flexible driveshaft and transaxle? A guy in Hot Rod built up a wicked Catalina and he said it was a bitch to modify/replace the rear suspension.

These B bodies have traditional trans and driveshaft. You might be thinking of 63 Tempest? think 'My Cousin Vinny' haha. And I can imagine it would be a big project to customize one of those, but would be fun.

61 Fullsize has a 4 link rear suspension and is actually a very good design. I put in tubular control arms. On the 61, the front end is the suspension that needs some work. originally came with negative caster (wtf right?) and rear steer tie rods with too small of an idler arm. I did some work to try to fix most this stuff, and it really is great to drive.

It's hard to describe how much fun I've been having in this car. I'm almost finished with the details, but dang I can't stop driving it to finish the little things. I did so much homework through the whole process and it really paid off. I think I have the right combo motor/trans/rear, efi, steering mods, etc. only thing i'm left wanting is AC. maybe next season...

https://static1.pt-content.com/images/noimg.gif


https://static1.pt-content.com/images/noimg.gif


https://static1.pt-content.com/images/noimg.gif

[Zarp51]

[QUOTE=TheMonkey;911437]Sounds great, good luck with new motor - would love to see pics! Thanks for bringing up this post, i'll update pics below.



These B bodies have traditional trans and driveshaft. You might be thinking of 63 Tempest? think 'My Cousin Vinny' haha. And I can imagine it would be a big project to customize one of those, but would be fun.

61 Fullsize has a 4 link rear suspension and is actually a very good design. I put in tubular control arms. On the 61, the front end is the suspension that needs some work. originally came with negative caster (wtf right?) and rear steer tie rods with too small of an idler arm. I did some work to try to fix most this stuff, and it really is great to drive.

It's hard to describe how much fun I've been having in this car. I'm almost finished with the details, but dang I can't stop driving it to finish the little things. I did so much homework through the whole process and it really paid off. I think I have the right combo motor/trans/rear, efi, steering mods, etc. only thing i'm left wanting is AC. maybe next season...

https://static1.pt-content.com/images/noimg.gif


https://static1.pt-content.com/images/noimg.gif


https://static1.pt-content.com/images/noimg.gif[Unlike the 61 Chevrolets that had a fairly nice rear suspension but only one upper control arm that always broke off at the frame (I have two 409 cars) the pontiac's have a bullet proof rear suspension cant imagine downgrading to a nine inch ford setup. Where did you get your steering wheel rebuilt?
I have two but they're a mess.

[Zarp51]

Love to post some pics, if I could just figure out how? Cant seem to find the browse feature. Heh Heh (like in E-Mail.)

[TheMonkey]

Dennis at Quality Restorations in Poway did the steering wheel. $$$. I had to sneak it in the house :)

For pics I upload to hosted site like image shack then just reference the URL with the insert image button.

[xplane]

Car turned out really nice! Sounds like a killer drivetrain.

I have a 61' Invicta bubbletop, but the drivetrain is just restored to stock.
60229

[TheMonkey]

Love the stance!

[xplane]

Thanks,

The bags are deflated in that picture so it is not operable at that ride height.

Looking forward to your project updates, keep us updated!

[smashedfoot]

I was curious what you did with your front suspension to get rid of neg caster. I have a 62 catalina I'm starting that I got for $600 (it's a shell) and in the same condition as yours was. I'm planning on road coarse racing not really show so I'm looking for better front setups. Maybe scrapping this rear steer weird sway bar mounted no disk havin front setup for something newer. looks like it wouldn't be that hard to weld in whole front clip from a better car. Everythings still in the air right now but I was curious how well yours worked out and if it has disks too. Any help is greatly appreciated :)

[TheMonkey]

I was curious what you did with your front suspension to get rid of neg caster. I have a 62 catalina I'm starting that I got for $600 (it's a shell) and in the same condition as yours was. I'm planning on road coarse racing not really show so I'm looking for better front setups. Maybe scrapping this rear steer weird sway bar mounted no disk havin front setup for something newer. looks like it wouldn't be that hard to weld in whole front clip from a better car. Everythings still in the air right now but I was curious how well yours worked out and if it has disks too. Any help is greatly appreciated :)

Negative Caster:
I ended up cutting out shock towers from frame and clocking it back a bit. This worked well, but it was difficult to get just right. I ended up with -2.5* caster. I'd like a bit more. Here's the way I will do it next time: the control arm is triangular - cut the forward link just outboard of the forward bushing. filet the rear link just outboard of the rear bushing. rotate triangle back until you have 1/2" gap in forward link. weld in support inside and outside of the stamped arm, box the bottom of arms including surgery area. This will give you 5 degrees from a stock arm. Custom arms would be tough because there is a big drop in them. of course anything is $-possible-$, but modifying stock setup is an easy way to get there.

I love your choice of 62 cat. But it will be a challenge to turn it into a road racer. Whole new front clip would be the right choice if you are serious about driving it hard, but you can make a lot of progress from the stock setup.

For the rear steer, I made a new heavy center link and idler arm. Problem with rear steer is the linkage compresses instead of stretches on turns and it becomes too compliant. The original idler and centerlink are not good for this. Here is a link to my fix: http://forums.performanceyears.com/forums/showthread.php?t=648733

Take a hard look at factory welds. They are not good. Fix where necessary.

Consider supports from rear crossmember to frame. Here is my problem and fix for that: http://forums.performanceyears.com/forums/showthread.php?t=715286

I have discs front and rear from scarebird. Works great if OEM discs are enough for you.

Quick ratio conversion to steering box also and I love the way my car drives.

Rear sway bar from Brad at Fabcraft was an excellent improvement along with new fat front sway.

[smashedfoot]

Thanks for your reply! I'm still all over the place on what I'm going to do with the car but they do autocross here in Fresno CA and I would like to hit up Buttonwillow and Laguna Secca/Infinion raceway. I'm curious how these guys used to road race these cars back in the day when they were at the top of the podium in NASCAR? 4 wheel drums no power steering and no safety equipment... That takes Cajones! Thinking of a 75-81 camaro/firebird front clip. can be had for around $250 and just switch the rotors out for big car. I'd get 1 1/8" swaybar disk brakes and quick ratio tall spindles for $250 plus whatever little tid bits that come along with it all. I scored an 94 caprice disk brake 8.5 posi 3.08 rear axle with 1" swaybar for $80 on half off day at the yard:) and have 3.73's for it. was looking for original third member but maaaan do they want a mint for those!!! They make full roller bearing bushings for the front a arms that I found on circle track supply as well as other parts for that setup. I saw your post about the upper a arm with Mark at SC&C and checked out his arms. Look pretty sweet but you have to pay $$$$ for it as you stated. probably could hve whole front clip in car for the price of those arms and have all advantages that come with it. I guess I'm answering my own question... I'm going to measure my buddies trans am and see if it will work:)