Author Topic: 1275 A+ Engine Build  (Read 43014 times)

Offline BruceK

Re: 1275 A+ Engine Build
« Reply #225 on: November 17, 2017, 06:48:58 PM »
Very cool.   

Ive got an idea: Why not create a throttle lever like on a boat and that way you can mount it it next to the instruments on the console so you can adjust engine speed more easily?

Oh wait.  Add a second one for choke control!
1988 Austin Mini
2002 MINI Cooper S
2007 Triumph Bonneville

Offline MiniDave

Re: 1275 A+ Engine Build
« Reply #226 on: November 17, 2017, 07:11:24 PM »
Yes, that may happen eventually.....as long as I keep using the same carb.
1989 Cooper Racing Green
2009 Clubman S
1969 Jaguar XK-E FHC
2004 Audi Allroad 2.7 TT

Offline MiniDave

Re: 1275 A+ Engine Build
« Reply #227 on: November 18, 2017, 05:13:16 PM »
One last short vid of it revving....

A new gasket fixed the water leak at the thermostat housing. Changing the needle and jet made no difference in the way the carb worked, I either need to get a different one or see if I can figure out what the heck is wrong with this one. If I had a known carb I could slap on it then I could use it for a baseline and go from there.

Sounds really good now, ready for Dan to come up and haul it off, I'm sure he's anxious to replace the ailing 998 and see what this one will do with his dual carb setup. Should run considerably better than a 998 running on three cylinders.....


1989 Cooper Racing Green
2009 Clubman S
1969 Jaguar XK-E FHC
2004 Audi Allroad 2.7 TT

Offline John Gervais

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Re: 1275 A+ Engine Build
« Reply #228 on: November 18, 2017, 09:54:56 PM »
Did you try to connect those two hose nipples on the carb?
- Pave the Bay -

Offline MiniDave

Re: 1275 A+ Engine Build
« Reply #229 on: November 19, 2017, 07:59:57 AM »
John, where are those pics posted again? I can't seem to see them....I wanted to look at them again.

Edit: found them, no - I will try that next, thanks! You are an absolute fountain of information!
« Last Edit: November 19, 2017, 08:06:15 AM by MiniDave »
1989 Cooper Racing Green
2009 Clubman S
1969 Jaguar XK-E FHC
2004 Audi Allroad 2.7 TT

Offline MiniDave

Re: 1275 A+ Engine Build
« Reply #230 on: November 19, 2017, 05:03:59 PM »
No joy John, hooking those hoses up the way it looks in your last photo results in a no start, unhooking them the engine starts right up and runs as before.......I need to study on this carb some more.

But it did allow me to run the engine in and get the timing set. Today I re-torqued the head and reset the valves. The timing is set a little conservatively at 4* BTDC instead of the usual 8*

Tomorrow I'll pull the engine out of the stand and load Clancy's Moke engine in and start the process on it to see if it will start.....I think it will, it's basically a stock 1275 AA motor and it turns over smoothly without the plugs - I did squirt a little Marvel oil down the bores and let it set over night before I tried to roll it over, but it cranked over easily enough and it didn't sound like there was any rust in the bores. Clancy sealed all the openings with metal duct tape so it had little chance of any moisture getting in and ruining things. We'll see what happens next. I'll start a new thread for that one.
« Last Edit: November 19, 2017, 05:10:04 PM by MiniDave »
1989 Cooper Racing Green
2009 Clubman S
1969 Jaguar XK-E FHC
2004 Audi Allroad 2.7 TT

Offline Lone Star Mini

Re: 1275 A+ Engine Build
« Reply #231 on: November 19, 2017, 08:35:23 PM »
Wonderfully impressive..
Lone Star Mini
1982 Morris Mini 1000HL (heck of a lot of work ahead of me)
1992(?) Mini Cooper
1964 Austin Cooper

Offline John Gervais

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Re: 1275 A+ Engine Build
« Reply #232 on: November 20, 2017, 09:04:55 PM »
Interesting - I seem to recall reading an article many years ago (KC?) that said those nipples should be connected.  Hence the pictures saved on my PC. 

Oh well - at least that engine sounds like it's running pretty sweet and the test stand is working well.
- Pave the Bay -

Offline MiniDave

Re: 1275 A+ Engine Build
« Reply #233 on: November 24, 2017, 09:48:42 PM »
I'm pretty happy with it these days, I can see several things I could have done better or differently but I'm OK with it so far.....
1989 Cooper Racing Green
2009 Clubman S
1969 Jaguar XK-E FHC
2004 Audi Allroad 2.7 TT

Offline John Gervais

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Offline MiniDave

Re: 1275 A+ Engine Build
« Reply #235 on: December 09, 2017, 09:37:12 AM »
Red letter day, Dan came and picked up his engine yesterday, along with a few other parts. Future updates will come from him as he decides which car in his fleet will get the hot motor....I encouraged him to put it back in his Pup - mostly so he will finish it after 7 years!   ;D

Can't wait to hear how it performs, but it sure sounded good on the test stand.
1989 Cooper Racing Green
2009 Clubman S
1969 Jaguar XK-E FHC
2004 Audi Allroad 2.7 TT

Offline 94touring

Re: 1275 A+ Engine Build
« Reply #236 on: December 09, 2017, 04:00:52 PM »
The truck has been parked a solid 10 years now!

Offline MiniDave

Re: 1275 A+ Engine Build
« Reply #237 on: March 20, 2018, 07:33:26 PM »
Well, after completing the hot rod motor and sending it back to Tulsa, Dan's lost his mind and brought it back for a few more mods!   ;D

So today I finally got healthy enough to begin the job, and it is a job let me tell you.....he wants to change the final drive to 3:44 from the 3.1 it was - that's not too bad a job, I wouldn't have to separate the transmission from the block to do that, but he also wants to put in a center oil pickup - which does require separating the block and trans, which also requires removing the clutch and flywheel and the rear cover. It also means removing the lay shaft and laygear, as the standard oil pickup won't come out any other way, and the center oil tube has to go in at the same time as the laygear - makes for a bit of a dance to get them all in place at once.

Tonight I got it all torn down, tomorrow I'll start the cleanup process, removing all the gasket bits and leftover RTV and such, then I can start changing out the diff gear.

I tore the old one down tonight from the donor gearbox and got the carrier all apart, tomorrow I'll post up pics of the difference between it and the new cross pin carrier as I reassemble it.

Lastly, before it goes back home I hope to get it in the engine stand and run it some with the new carbs! Stay tuned, more as it happens!

Here are few pics of the teardown.
1989 Cooper Racing Green
2009 Clubman S
1969 Jaguar XK-E FHC
2004 Audi Allroad 2.7 TT

Offline MiniDave

Re: 1275 A+ Engine Build
« Reply #238 on: March 20, 2018, 07:35:59 PM »
A couple more showing the center oil pickup under the lay gear, and the final drive assy out of the box.

Doing all this is just short of a gearbox rebuild!

I've already installed the 3:44 pinion here, but haven't torqued it yet.

I looks like the final drive cover was just installed with RTV, no gaskets. I always used the factory gaskets, but maybe there's a trick here, I'll have to check into it before I put it back together. I think this box has been gone thru before, there was a lot of locktite used on the bolts, the factory never did that as far as I know. Also near as I can tell without removing them, the synchros look to be in top shape.

I have to completely disassemble the differential carrier in order to change out the center part as well as to change the crownwheel.
« Last Edit: March 20, 2018, 07:42:53 PM by MiniDave »
1989 Cooper Racing Green
2009 Clubman S
1969 Jaguar XK-E FHC
2004 Audi Allroad 2.7 TT

Offline 94touring

Re: 1275 A+ Engine Build
« Reply #239 on: March 20, 2018, 07:45:11 PM »
Sweet, looking good.  Plus an even lighter flywheel this time too! I need to order my engine paint tonight.

Offline Jimini II

Re: 1275 A+ Engine Build
« Reply #240 on: March 20, 2018, 10:45:03 PM »
The D series can use 10 inch wheels and Mini suspension and brakes which cuts the cost down considerably. John Mc Gee makes a sub frame for around $1900 which uses all the Mini components. I have seen a couple done by using the Mini sub frame and working it to suit. The D series engine is also a lot cheaper to buy than the B series. If you do a B series swap the issue i have heard is getting the HP to the street unless you go RWD.
Joe Schott/Tow Joe told me his 1293 engine and gearbox re build cost him around $2200 and he did everything himself except the machine work.

Offline 94touring

Re: 1275 A+ Engine Build
« Reply #241 on: March 21, 2018, 04:36:11 AM »
Yes but then I'd have a d series Honda motor in my mini.  I'm not opposed to engine conversions and wouldn't be surprised if someday I have one.  The problem for me is it takes a huge part of what I love about minis out of the mini.  I'm not completely sold on handling characteristics of the d series conversion having driven one.  Fast yes, but felt heavy on the wheel.  Similar to the d series swap would be v8 swaps into my rx7. A lot of guys do it for the same reasons as mini guys, and it's tempting, but then I have a boring v8 that doesn't drive the same.  I'm more likely to do one of these 16v mini head conversions to get d series power in my mini.

Offline MiniDave

Re: 1275 A+ Engine Build
« Reply #242 on: March 21, 2018, 01:56:20 PM »
Today I cleaned the case again, there was a surprising amount of sludgy gunk in the bottom, considering how much I cleaned it before I put it together the last time, so I put it in the solvent tank and gave it another good rinsing out. It took about an hour to scrape all the old gasket material off but now it's all clean and ready to reassemble.

Next up was to build up the cross pin diff and change out the crown wheel. Disassembly is easy enough, just remove the bearings and unbolt the crown wheel, then remove the stub axles as they will be used in the new cross pin housing. The kit comes with new thrust washers and spider gears and their thrust washers too.

The only fiddly part of the reassembly was getting the short side shaft into the cross block, it has a pin that has to locate in the long cross shaft and for that to happen it all has to be lined up perfectly..... took a bit of fiddling and repeated trials till I got it lined up, then it all went together smoothly from there. Then it was install the second stub axle, bolt the crown wheel on and torque to 60 ft lbs, then tap the carrier bearings into place....interesting to see the difference in the carrier bearings between this box and the one the 3:44's came out of....I don't know which is older/newer, but the big bearings were on the gearbox for the 998.

Next I'll reassemble the box, put the diff in and torque the pinion bearing nut, then put the center oil pickup and layshaft in, then the retaining plate for the pinion bearing and layshaft, then bolt it all back on the block, add the rear cover and drop gear, clutch and clutch cover - and the new lighter flywheel of course, then mount it in the engine stand and see if it will run!

But before I can do any of that, Roses' Audi parts came in today, so .......priorities. Happy wife, happy life, right?
« Last Edit: March 21, 2018, 02:00:24 PM by MiniDave »
1989 Cooper Racing Green
2009 Clubman S
1969 Jaguar XK-E FHC
2004 Audi Allroad 2.7 TT

Offline 94touring

Re: 1275 A+ Engine Build
« Reply #243 on: March 21, 2018, 01:59:09 PM »
Looking good  4.gif

Offline MiniDave

Re: 1275 A+ Engine Build
« Reply #244 on: March 21, 2018, 06:57:34 PM »
Gearbox is done and ready to be mated back with the engine, then I'll set it up in the engine stand and see if it will run again.

Yes, there are three small bolts leftover, that's due to the different mounting of the center oil pickup, not because I couldn't remember where to put them!   ;D

Although I did have some consternation with the side cover bolts...... turns out the left side ones are about 1/4" shorter than the right side, I had to lay them all out and count them to remember which went where.  8.gif ::)
« Last Edit: March 21, 2018, 07:03:58 PM by MiniDave »
1989 Cooper Racing Green
2009 Clubman S
1969 Jaguar XK-E FHC
2004 Audi Allroad 2.7 TT

Offline bikewiz

Re: 1275 A+ Engine Build
« Reply #245 on: March 21, 2018, 07:10:05 PM »
You better watch out for the Blue Bunny Ice Cream, too much and you won't fit in a mini :D

Have you heard about later trans having issues with popping out of reverse? All of the forward gears work perfect up and down but if you don't keep your mitt on the lever it will pop out of reverse.

Offline MiniDave

Re: 1275 A+ Engine Build
« Reply #246 on: March 21, 2018, 07:27:06 PM »
I had not heard that actually.......all the rod change gearboxes I've ever driven work really well, other than the occasional worn 2nd gear synchro.

My 110lb wife eats the ice cream, not me - she likes to make homemade chocolate malts with it. If I ate them you're right, I would not fit in my Mini - I barely do as it is!
« Last Edit: March 21, 2018, 07:28:47 PM by MiniDave »
1989 Cooper Racing Green
2009 Clubman S
1969 Jaguar XK-E FHC
2004 Audi Allroad 2.7 TT

Offline bikewiz

Re: 1275 A+ Engine Build
« Reply #247 on: March 21, 2018, 07:39:52 PM »
Ya it's weird. My '71 had worn syncros in 2nd (and a bunch of other broken and f'd up stuff and rust and it smelled like the bottom of a trash can and it didn't stop because the front shoes looked like cheese cloth) but reverse was never a problem, this car ('91ish) has perfect syncros but if you let off the gas ever so slightly in reverse it pops into neutral, keep your mitt on the lever no worries, which makes reversing into a parking spot or the driveway real easy.....

Offline Jimini II

Re: 1275 A+ Engine Build
« Reply #248 on: March 22, 2018, 08:50:39 AM »
Yes but then I'd have a d series Honda motor in my mini.  I'm not opposed to engine conversions and wouldn't be surprised if someday I have one.  The problem for me is it takes a huge part of what I love about minis out of the mini.  I'm not completely sold on handling characteristics of the d series conversion having driven one.  Fast yes, but felt heavy on the wheel.  Similar to the d series swap would be v8 swaps into my rx7. A lot of guys do it for the same reasons as mini guys, and it's tempting, but then I have a boring v8 that doesn't drive the same.  I'm more likely to do one of these 16v mini head conversions to get d series power in my mini.

Yeah i was just comparing the two and the fact that the D series can use the Mini suspension and brakes. I am on the same thoughts i would rather keep my Mini's all Mini but i do have a Clubman Estate i am thinking about converting along with adding the Honda a/c it is just so original and not rusted out i hate to not keep it that way. Surprised you felt the D series was heavy as i thought weight wise it was about the same as a Mini set up.

Offline Jimini II

Re: 1275 A+ Engine Build
« Reply #249 on: March 22, 2018, 08:58:18 AM »
I had a 90's Mini that jumped out of reverse and occasionally 2nd gear. I found that when you put it into gear 2nd 4th and reverse it felt squishy unlike 1st and 3rd which felt normal. Looking at the linkage i noticed the bellows around the shifter rod seal shaft were too thick and not letting the shifter engage 100%. I cut them off and all the gears felt the same no more jumping out of 2nd but reverse was still an issue under a hard load (backing up a hill). Most times out of habit i just rested my left leg on it while reversing it was never much of an issue and sold it to a guy who was going with a B series conversion so it was not an issue to him.