So I'm considering the mechanical direction to head in for the Ke70 sedan Ive bought.

The car currently runs well with stock as a rock 4k and auto.

Ive been reading up heaps on the thousands of different options and am leaning towards one of 2 plans.

 

A: Cam, carb, exhaust and shave the head on the stock 4k motor.

-cam: possibly a Tighe grind as they are local

-carb: whatever I can find or make fit (single downdraft webber/dellorto, single sidie or whatever, twins will prob break the budget)

-1.75-2inch zorst

-shave head

 

B: Buy some other kind of cheap, carbied larger capacity toyota engine(I know of an 18r thats available) that drops in easily.

-could do 5k, 7k, 18r

 

 

regardless of which, if either, way I go I also want to chuck a manual box in it so will need to chase this also.

 

Can I ask a few questions to clarify my findings?

1. Is it true or bullcrap you can bore a 4k to take 5k pistons?

2. to get 9.5-10:1 comp ratio do you shave a stock 4k head 20 thou?

3. Are 32/36 webbers crap on a 4k (some say chokes are too big, if so how do you fix this)

4: If I find an 18r and 5 speed, will I need a new tailshaft? (I'm shying away from a diff upgrade just yet)

 

Cheers for any help/advice

 

Jes

Easiest and cheapest would be a 5k. Bolt in and enjoy the torque.

1. Is it true or bullcrap you can bore a 4k to take 5k pistons?

Yep, done it, but we haven't run it for long enough to see how it stands the tests of time. Richo has got very busy and shelved the 345K before we solved the oil leak. I have reports on a handful of others theat have been done too.

 

2. to get 9.5-10:1 comp ratio do you shave a stock 4k head 20 thou?

Near enough. Its not hard to measure your head volume and calculate how much to mill off.

 

 

3. Are 32/36 webbers crap on a 4k (some say chokes are too big, if so how do you fix this)

I don't know, but quite a few guys use them. They work, but you may need smaller chokes and jets to make them work well. There are 28/36 versions of that carb around, but not as common.

 

 

4: If I find an 18r and 5 speed, will I need a new tailshaft? (I'm shying away from a diff upgrade just yet)

I expect that the shaft will need a different length and a different nose. Then balancing for a couple of hundred bucks. You'd also need new g'box mounts and probably engine mounts too. Then the exhaust will need changing.. Its easier to stick to a K motor.

If you want to have some quick and cheap fun and want to get your hands dirty, stick with cam/carb/compression on a 4k. If you want something faster with an old school feel get a carbed T or A engine.

 

Cam - $120 (Get something with a relistic powerband, 2000- 5000RPM, or you'll have a bad time)

Shave head - $80 (Learn to calculate how much to remove and what compression ratio you want and the difference between dynamic and staticCR)

32/36 - ~$100 setup (It will work fine, maybe not optimal but for a 4k you won't care, put effort into jetting and getting rid of vac leaks)

 

Timing advance is free ;)

 

Exhaust will be the most expesive part, so put a less restrictive muffler on or replace it with a resonator depending on your taste and call it good. Pick up a second hand set of extractors if you really want, but the standard aftermarket ones are crush bend and unequal anyway.

 

You'll get more out of the car if you spend money on tyres and suspension setup. Just get the engine running nice and hit up a few twisty roads and enjoy the thing.

Yep, done it, but we haven't run it for long enough to see how it stands the tests of time. Richo has got very busy and shelved the 345K before we solved the oil leak. I have reports on a handful of others theat have been done too.

 

Be careful!

it is defiantly possible if done the right way.

the castings often don't line up with the bore positioning, if you are going to do it make sure to have the block sonic tested.

it is a very simple 1/2 hour procedure for people that know what there doing and will tell you straight away if it is going to work or not.

try to keep the wall thickness to a minimum of 0.120"

-Phil

 

and +1 for more money spent on suspension,

$1000 spent on the right suspension setup will handle like a circuit car

$1000 spent on a 4k will still be a 4k, but a bit louder.

the castings often don't line up with the bore positioning, if you are going to do it make sure to have the block sonic tested.

it is a very simple 1/2 hour procedure for people that know what there doing and will tell you straight away if it is going to work or not.

try to keep the wall thickness to a minimum of 0.120"

 

True- the sonic testers are around at many engine shops, cost around $100 for it to be done here. Then they know which way to move the bore a mm or so to keep the bore wall thickness even.

 

$1000 spent on the right suspension setup will handle like a circuit car

$1000 spent on a 4k will still be a 4k, but a bit louder.

 

LoL! Also sadly true.... But a cam/carb/exhaust will allow it to keep up with the traffic at 100kph until you get to a steep hill!

Please excuse this "Merican"...

 

4k - 72#/ft of torque (plus or minus)

 

18R - 108#/ft of torque (plus or minus)

 

an extra 36#/ft of torque makes for a totally different car........ :kiwi:

 

if he is going through the crap to go from auto to manual anyway(cost), how hard is it to source, or build the few bits and bobs needed to swap and get the substantially added power??

Edited March 3, 201511 yr by oldeskewltoy

To take a different angle, check out your rego and vehicle modification laws before you pour too much time and energy into your car. It would suck to go for an 18R or similar, get pulled over and have it defected, impounded, crushed (OK I'm being dramatic), etc. The more modified everything is, arguably the higher the chance of trouble.

 

Of course if it's for track work, ignore everything I've just said :)

 

I had a 4K with shaved head and 32/36 on it. It was a lot of fun! Not a heap of power, but was certainly quite drive-able. It was used for motorsport, so I can't comment on fuel consumption, but it didn't seem outrageous.

Edited March 4, 201511 yr by snot35

Depends what you want to do with the car? What are you looking for exactly

 

I've personally done a 3TC into a Ke70 with a T50 running and driving for $350.. That's virtually the price of a cam and manual swap for a 4k.

 

3tc in ke70 was great, Super easy and went well with the Weber and extractors it had on it.

 

There are options that aren't hard and can be done cheap and are a lot better than 4k.

Thanks for the replies fellas, i intend to use the rolla as a daily. I'm open to suggestions of different motors, preferably toyota. The main requirements are that any conversion be cheap (hopefully sub $500 ish) and easy (virtually bolt in).

I'm in qld and was at an engineer mates place yesterday who looked up for me the legal requirements are:

For NA engines

original vehicle wt (950kg)x 3 then change to CC so this is 2850 or 2.85 L

 

For forced induction same equation x2.5 (instead of 3) so 2375 or 2.3

 

Would love to try a tuned NA 3rz motor but thats well out of the budget.

 

Hadnt considered the 3tc option yet, thanks Jono!

 

Anybody located in Qld want to sell me some kind of replacement motor and 5spd box?

Open to offers/suggestions,

Jes

7K it, and keep the auto until youre ready to spend some more $ on it?

Ive got an ancient 8r you can rebuild. Its a rare bird.

Having done a manual swap on a K power ke70, it was a very good bang for buck performance mod. Would 100% recommend. Also, if you want to save money get a 4 speed, same ratios just minus 5th.

Incorrect. k40 and k50 actually have different ratio's. It's in the FAQ as well.

If your budget is $500 I'd stick with the 4K. Do a manual swap first and then see how much change you have left afterwards. The more you change, the more it's going to cost and you might end up having to change things you didn't expect, radiators, mounts etc. That'll quickly tank your budget and keep the car off the road for longer.