I'm thinking about fitting a 1600tp to my bug. I know most of things I have to do, but my main question is fitting a later gearbox. It currently has a 36 horse box, the one with no synchro on first.

Will a later swingaxle box bolt straight in?
What are the best swingaxle boxes in terms of ratios?
Is there anything else I shold know about doing this procedure?

Ok you need to do a couple of things.

Firstly i'm assuming the engine has the late style 200mm flywheel.

- 1200 engine flywheels have no o-ring and are only compatible with 1200 crankshafts.

-flywheels for beetles are either 180mm or 200mm. the 1200/1300 engines had 180mm and the 1500/1600 had 200mm.

-200mm flywheels will only work with 12v starter motors and 180mm flywheels with 6v starter motors. To fit a 6v starter in a 12v box or vice versa you need to put a conversion bushing in your box.


The first problem is that the swingaxle gearbox is only large enough for an early style 180mm flywheel. One way to get around this problem is to fit an early 1300mm flywheel. The other solution is to clearance the gearbox, you grind away at the bellhousing until the flywheel can turn relatively freely inside it. Since you say you want to switch to a late gearbox anyway this should be easy, as clearancing involves grinding, fitting the engine to see if it fits and repeating. You do it with the box out as it's easier.

All the beetle swingaxle gearboxes are geared relatively high because they were paired with 1200/1300 engines.

There are late style swing axle boxes which have the late style throw out bearing in them. These gearboxes were paired with the 1300 tp and had a slightly higher ring and pinion i think...


I think the gearbox should bolt up pretty much straight.

Why not try the 1500 swingaxle gearbox? I'm not sure if it will help though, I'm just going on what Che said.

Pat, if you put a later swing axle box in you would want to change it to the 1200 short axles too. This will keep the 5 stud wheel bolt pattern and keep the wheels inside the guards.

Pat

The most important thing you have to check is the front gearbox mount... Some have the wrap around mount n some have the square later model that a 40 hp gearbox will bolt up to.

If you have the wrap around type then this will have to be changed and a new mount welded into position.

If your have origional heater boxes fitted to the engine then the R/H side top of the geater box needs to be cut down so it will fit under the rear engine fire wall on the body work. Otherwise you have to push n shove to get them to fit.

I fitted the late 1600cc to a 1500 swing axle gearbox to my early beetle, no clearancing.
I liked the long axles so had steel rims made with offset in - sit inside guards lovely.
My gearbox mount was an issue , I just made an adapting mount.
-
If I have any gearbox problems then the standard 1500 gearbox goes straight in.
No axle changes , or mount changes , or clutch or flywheel problems.

I'm pretty sure it's the wrap-around style mount. Is it possible to make an adapter, or do I have to weld a new mount in?

So I'm looking for a 40hp gearbox then, as this has lower ratios and short axles?

Can I bolt up a 1600 to my existing box?

Thanks for the info.

So there will be no problems with the 36hp box handling the power of a stock 1600?

I dont think so as the bearings and gear are a lot larger in the 36 box than the later style....
Its just that the old box may be worn and extra load may make it fail easier.

Hi

The rego people would most likely want you to fit front discs as well. Find a 1300 twin port motor AB engine number, you can do all the usual things to these motors that you can do to a 1600, but you wont need front discs.

1302Steve

I doubt that there's heaps of people down here running 1600s in ovals with drums. I think Vicroads is a bit slacker than what you NSW guys have to deal with.

as far as the front mount is concerned i know that the standard thing in the US is to fit the g.box nose cone off an early 60's kombi onto the g.box you intend to use, removing the need to modify the mount on the car (if this works on australian spec cars i cannot answer having never tried it)
another thing to think about, only a minor detail bit still makes life much easier, is that DP motors are designed to have the top LHS engine mount undone from under the car and the earlier cars from inside the engine bay. the earlier g.boxes have a casting to stop the nut/bolt spinning during this process which makes life hell if you haven't cut this back before trying to do up or undo that mount bolt. (ask me how i know ) i found a little (gentle) modification with a cold chisel and a SMALL hammer did the trick quite cleanly.

Thanks for the tip Whatnow, I'll look into the nosecone thing, I think the Aussie cars should be the same in that aspect.

i have a 1641 in my oval with clearenced later swing axel. Here are some of my thoughts. If I were you, I wouldn't run the doghouse cooler on your car. The doghouse is alot bigger and needs a "dump" to exit the hot air out of the engine compartment. That dump doesnt fit very whell in an engine compartment that is made for a motor 300 cc's smaller. I you do decide to run the doghouse, you need to make a dump for the hot air that is passing out of the oil cooler, otherwise it will dump right on to your number three cylinder and heat it up a bit. You could run the dump for the hot air, but you would have to cut up the firewall to make it fit. But im not a big fan of cutting up early cars. My only other bit of advice, when installing the motor, take off the exhaust, all of it. trying to install that motor with later heater boxes and/or a header is a big pain in the ass.

Should I put in an external oil cooler instead?

Did you modify the gearbox mount, or use a bus nosecone?

Pat

Forgot about the Kombi gearbox nose cone....

Pat , Scott makes a good point about stripping the 1600 motor to fit them in. I have pulled out and put in few later motors in early beetles (mainly ovals) and I found you almost have to strip em down to get them out and in. The exhaust always has to come off. Extractor exhausts are a tight fit around the rear apron o early beetles too.

The other area to address is the rear piece of tin. 1600 bit wont fit the car and 36hp bit wont fit the 1600. Be prepared for a lot of trial and error cutting. Dont think about running with out this bit if tin as the motor will cook pretty quick during the summer.

Well, sorry to dig up an oldie, but the time has come....

I will be picking up my new engine later this week, and I plan to install it over the weekend.
The engine is a twin port 1600, already fitted with a 6volt clutch and flywheel, so that should save some hassle.

Wish me luck.