4age austin healy sprite conversion help please

[ehdave]

Hi guys,

I'm Dave. I'm new around here and I have recently purchased a 1966 mk3a austin healy sprite which is basically a body with hanging panels. I am also picking up a ke70 corolla with a big port 4age from a ae82 and a t50 gearbox next weekend for the engine and gearbox conversion parts. I am hoping to go to a 20 valve later on down the track.

For any one who doesn't know the car they are a small pommy sports car, this model weighs 676kg dry standard and came with an 1098cc engine and 4 speed manual. They are also basically the same car as an mg midget. I have come across a couple of these cars already with 4age motors on the net, but there's not a lot of info on the conversion.

This is the first engine conversion I have done so I'm a bit new to all of this and I could really use some help. So far I have come up with the following issues with the conversion and I would appreciate any help. I have been told that the 4age motors were installed at a slight angle, is this true and if so does anyone know how much of an angle?

The standard diff in these cars break with the standard 1100 cc motor and is only around 120 cm long, any suggestions on a diff that might handle the power of a 4age without cutting it down? Other than this I am looking at cutting down a r31 skyline diff (114.3 stud pattern for easier wheel options, ratio's and strength) or a series 3 rx7 if I can find one.

Also I am on the southside of brisbane and I am looking for a good engineer to help with the legal requirements for the car and do the engineering approval.

Any help would be greatly appreciated.
Cheers
Dave

[toddw]

Hi Dave

I am not aware that the 4age was on an angle. If it is it is very slight. You are welcome to have a look and take measurements at my AE86 Sprinter ( I am on the southside also). As for the rear end it depends on what you are planning to do. A Toyota S series might be all you need. S series are drum brakes. The S series can be had for next to nothing on the foums such as this. They are great if you don't intend to do bvurnouts etc or alternatively upgrade to a T series JDM rear end which are disc brake. Let me know if you need more info.

ToddW

[ehdave]

Hi Toddw,

Thanks for the info, sorry I should have mentioned that I am intending to use this as a daily driver as well as doing some competition (hill climbs and motorkhana's etc) so I want to build it nice and strong.

Is the s series whats in the ke70 corolla? (sorry I only know a limited amount about these cars). I would love to come around and do some measurements if thats allright, although I might wait it till a have an angle finder guage.

I also forgot to mention I can only use either 13 or 14 inch wheels due to fitment on the front end to get a decent width tyre under the car without scrubbing the inner guards (it will have some sort of flare on the outside).

Cheers
Dave

[Xauterus]

HI
I think you will have to cut down a diff to suit. If you want something decent then look at F series toyota. At least then you can get decent ratios and lsd's. Have you considered what class you want to run in? A mate of mine runs a nissan A15 engine and gearbox. The nissan engines are much more closely related to BMC. Escort diffs also offer a good range of ratios and reasonable weight.

Corey

PS Keep the wheel widths down to about six inches if you want to keep the handling ok

[Sam_Q]

got a pic of the engine bay?

[ehdave]

Xauterus,

Thanks for that, I get the feeling I will have to cut a diff down too. I know a 105e anglia diff is close enough to the right width and they are basically a narrower escort diff but they are really hard to find and I wonder if they can cope with the extra hp and torque? I think if I can find one its probably the easier option.

I was also looking at an a14 motor but decided that they were getting too old and hard to find in good condition plus I really like the 4age motors and found one cheap. I haven't honestly thought about what class to run in, I'm mainly looking at club events (I'm a member of the Ah sprite club here in brisbane).

Sam_Q

I have added a few pictures, one of the engine bay another of the shell and one of my uncles mg midget that runs a 1500 spitfire motor at a recent club skid pan day at Gympie (was a heck of a lot of fun)

Cheers
Dave

[ian]

hi dave
great choice for a project
get in touch with colin dodds
he is in dural nsw i think thats near hornsby
ph 0414789263
he is a wealth of information, as well as parts
he can also steer you to a telescopic front end conversion, that gets rid of the pissy little lever action shock asorbers
i have been a member of the austin healey sprite club for 40 odd years and raced many sprite variations
i can put you in touch with a few of the guys here that have done the exact same conversion
there are a combination off bell housings that can be used , only one of them get everything to line up, particulaly the shift lever ,there is a combo that gets the lever to come out the original hole
most of the guys use a hyundai exel radiator as the fit perfectly apart from drilling a couple of holes
up until late last year i had a sprite shell here to do the same conversion .but i gave it to a fellow club member that had less projects on the go than i had
also
get in touch with this guy bob lomas ,
he has just completed the same conversions, and will be able to tell you exactly what he did ,just tell him ian from the sprite club suggested that you get in touch
good luck with it and keep us informed of your progression
[email protected]

here is a piccy of one of the sprites i had



good luck with it, and keep us up to date with the progress

[mattysshop]

the bottom of the sump sits level.. you can see the cam covers arn't level...

[Sam_Q]

Interesting project, with a 4age this would be very quick, can you do a worklog when you get started?

In an ae86 the block is on a 5 degree slant, well 5.1 to be exact. However the mounts are not perfect and the sump will about about a degree out, so do as the guys here have said and just go off the bottom of the sump.

I strongly suggest you don't fit an R31 diff or F series or anything like that. With the weight you have and just a normal 4age you could use just about any diff. Those others are quite heavy and would really weight your car down. I think a T series chopped down would be the way to go, thats anything from any RWD celica that has a solid diff. That means you can drop in any Japanese LSD intended for an ae86 and not have something overly heavy. You could go lighter again but nothing comes to mind thats a solid diff and has LSD's available for it. Might be worth looking at RT142 Coronas as I am unsure if they have T series diffs but do have disk brakes standard that suit small wheels.

The bigport your going for is a good choice and it's also good because as you say you can go for a 20V later on, seems like you have decent room for it too. Another bonus is whenever you upgrade it's very easy to sell your old engine as a package.

If you want to do some reading I have some articles on my website that you might fins interesting, most are aimed at 20V engines but a lot can be applied:

http://s-86.com/articles.html

[timbosaurus]

I was hoping Ian saw this thread!

Ian, you had an 18RG in one didnt you?

[ehdave]

Hi Ian,

You may well know my father (Alex Robertson), he knows Colin and Bob well as he has raced sprites since the 70's and is currently building a mk3a with a lenham body for historic racing, here's a link to his car
http://www.lenhamspridgetregister.co...Robertson.html
He was a member of the victorian sprite club until we moved up here and is now president of the brisbane club.

Your old car looks like a bundle of fun, are they 7 inch rims under it? I really like the look of it.

Hi mattysshop,

That picture is a huge help, gives me a much better idea how the engine sits normally (the corolla I'm getting the motor from hasn't yet had the engine fitted). Looks like a really nice setup too.

Sam Q,

Thanks for the link to your website, it will be a huge help. I hope to do a work log with lots of photo's, but I get the feeling it will be a slow progress project as I work a 50 hour week and have my kids every second weekend (maybe I should get them turning some spanners).

I do still have the origional diff which weighs bugger all but is very weak, I know an anglia diff is not much heavier and I have heard series 3 rx7 diffs aren't much heavier (still sceptical about that one though). I definately agree I need to keep the weight down as it would lose a lot of its purpose if it was too heavy. I do want an lsd as well, but I think that will have to wait until I have the car on the road (priorities).

Thanks for the info on the angle as well, I have just bought a guage from ebay that sits on the part to give the angle (should be helpful setting up motor, gearbox and diff).

I think this should be a nice quick package as the car is even lighter than a standard car as it has a fibreglass sebring front end and the 4age and t50 are pretty close to the same weight as a bmc motor and gearbox (about 20 pounds difference with ac and p/s which mine wont have).

Thanks every one
Cheers
Dave

[ian]

hi dave
well it is a small world
your dad and i go waaay back
say hello to him for me
ian

[ian]

I was hoping Ian saw this thread!

Ian, you had an 18RG in one didnt you?

hi timbo
no i was an idiot before my time
i ran a bridge ported rotary ,it use to scare the shit out of everyone in its day
thats why i am grey now

[timbosaurus]

ah, that's right. I remember that story now

[oldeskewltoy]

(maybe I should get them turning some spanners).

nothing wrong with family spanner turning... many families spend quality time together in this pursuit