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3k carb on 4k / rusty 3kc block


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So my 3kc did a head gasket couple of weeks ago - no big deal until i pulled the head off and realized the entire head and block are rusted out. So I'm just weighing up my options of getting a 4kc for a couple of extra ponies or persevering with the original engine.

So my noob questions are:

Can i stick my 3k carb on a 4k? as i just bought a rebuild kit for the 3k carb and would like to use it

Is this block salvageable?  I think the elderly lady never used coolant and the vehicle did alot of sitting

 

apologies photography isn't my strong suite but some of the water-jackets have disfigured from rust

 

any info or advice welcome ! thanks for reading

 

 

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Edited by Lukaswg
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Doesn't look any worse than most engines ive pulled apart....Give everything a very good clean (without scratching the mating surface) and see how it comes up. 

put a straight edge across the diagonals of the block and see if its still flat. 

And don't put that head back on unless its been to a machine shop for checking and if required a shave to make it flat. 

I put a 3k carby on a 4k years ago. it worked fine, but i suspect it might have been a restriction, it was incredibly slow - but ultra reliable. .Maybe the jets should have been swapped to bigger 4k ones. i dunno, my carby knowledge is a little limited. 

 

 

Edited by ke70dave
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As well as what Dave said, tip the block on its side and scrape all the rust and gunge out of the water jackets, particularly around number 4 cylinder. The slow water flow at the back of the engine means the rubbish piles up around there and causes overheating.

Clean ALL the stud holes out with a rag on a screwdriver, then with a rag soaked in petrol on a screwdriver, then with a bolt of the same thread that has a wedge cut out of it with a grinder or hacksaw. That will clean the threads out. I usually spray it with Brake-clean aerosol after that and wipe them out again with a rag. Make sure you clean all the bolts and nuts, and oil them when assembling.

The manifolds need a straight-edge along them too, the differential expansion of the alloy & cast iron distorts them over the years and leaking exhaust gaskets result.

 

What I did is here-

https://www.rollaclub.com/board/topic/42407-the-girls-ke70/

 

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Hi Luke !

              From my experience, that engine looks pretty good.  As it's probably original, how many miles has it travelled, according to the speedometer ?   Little olde ladies, are not known for racking up big mileages, on their cars.

I accept your comments regarding the possibility of going to a 4K, but bear in mind, as these engines are probably 40 years olde, the 4K may be in more need of "care & kindness", than this 3K.

Can you look at the casting of the head, on the outside, between no: 3 & no: 4 spark plugs, & take a note of the number of the two digit head type.  That might assist us in identifying it a bit more.  Your pics don't show it; but on the very back of the head, there is either a plate or a circular water jacket bung.  This needs to come out to get access to all the "crud" inside.  Sometimes pressure chemical cleaning of the head water compartments will dislodge the crud, but frequently, the plate at the back, is corroded badly on the "inside face", & should be replaced.

Cheers Banjo

 

 

 

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Thanks everybody for the advice, good to hear some positivity about the 3k - The 3k has just over 190,000 kms on it, not much for a 3k. Much agreed about the 4k Banjo but i was hoping to get that tiny torque boost with a view to eventually boring out, i live in a hilly area and modern drivers aren't known for patience

i'll get some better pics of the head - either way i'll clean it up and hang onto it as it is the original engine for the vehicle

 

thanks again

 

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Hi Luke !

Quote

i live in a hilly area and modern drivers aren't known for patience

I know that feeling.   If you want/need torque, then you have to go for a 5K engine, out of a Toyota forklift of a Toyota commercial like the LiteAce van.

I had a 2 door KE55 once, that I fitted a 5K to, after driving it previously with a 4K.  It was like a whole new car, & it loved HILLS !

Cheers Banjo

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Love 2 doors, noted about the 5k i wish i could find a 5k easily - I did however prior to this post go through the throes of teeing up to look at a 4k this weekend so i guess I'll see if it's a good runner or a project you never really know until you start it up. Is there anything i should look out for? suppose to have 130 000kms and have seen regular usage  i was just going to pull some plugs turn it over look under the rocker cover - all the basic stuff.

I hate to ask THAT  question again but in your experience do the 4ks go a little bit better then the 3k? some people say yes some people say no difference atall

 

thanks again

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Well, I've never driven a 3K, but Wiki says-

3K, 1166cc, torque 67-69

4K, 1290cc, torque 72

5K, 1486cc, torque 85lb.ft

The 4K is 10% greater in capacity, and the 5K 15% greater again. You can see that in the torque, the 68 to 72 (6%) is less than a worn motor to a more-worn motor, while the jump to 85 (18%) is noticeable. So not much between a 3K and a 4K.

You could warm the 3K up to make it faster, but that is all revs to get power, rather than getting any more torque. You could slip a turbo or supercharger onto it, but if you had that much money for fun you could fit a 4AGE. Even a cam, a head job, twin carbs and extractor, and a bigger exhaust will add up in dollars. A 5K would be a great choice, but there aren't that many old forkhoists or vans around now. The Y motors would be a close fit too, also out of vans etc, and they're out to 2L with 120lb.ft of torque.

Price up rings and bearings on the 3K, do yourself a head job if the valves and seats are OK, get it skimmed and look for a cam with more lift but not much more duration. I can't think of a cheaper way for a little more grunt unless you're a welder who can make his own turbo manifold. All that stuff I did to The Girls KE70 made it a lovely car to drive, although fitting the 4AGE to it was chalk and cheese. Not so much faster, but it doesn't notice hills.

Oh, and #4 cylinder wasn't doing any work, it shouldn't be any blacker than the others.  Was the gasket blown between #2 & #3, the usual place when a head warps? or was it a problem at #4, the area where the motor gets really hot due to shit in the block?  Banjo has a lovely solution for that, he made a bypass system that moved water around the back of the head more efficiently. The water holes at the front of the motor are blocked off by the gasket to force water to circulate to the back, so Toyota became aware of this problem early on.

head.thumb.jpg.b03278316055bc8bcda6ebbdaa90077d.jpg

 

You know, you could cheat by fitting a 5-speed box and lowering the diff ratio..  Quicker acceleration & up the hills, and let 5th drop the revs for cruising.

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I've had a little experience with 3,4 and 5k's. Honestly I wouldn't waste my time with a 4k. If you have to get another motor find a 5k.

Real world example - a cammed 5k took 2+ seconds a lap off my time around the Ballarat autocross track.

Real world example 2 - up a local hill, the 3k (std healthy engine) would struggle to hold 100km/h in 4th. With the 5k (std healthy), it would accelerate in 5th up the same hill. 

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Like Col, I've had a fair bit of experience with 3K, 4K, & 5K engines.  

The 4K engine is nearly square (bore & stroke are almost the same dimension).  A "square" engine, is regarding as being a more free reving motor, with higher top rev limits.; especially if the engine is balanced.  One of the great attributes of any K series engine, is their bottom end.  Designed before a lot of "computer input"  early Japanese engines were over designed, as they did not want failures of a mass produced car.   I've always been amazed at some of the HPs, people have squeezed out of K series engines, without any strengthening of the bottom end, other than maybe hardened studs & nuts, for the bearing caps.  K series engines of all formats have had pretty poor inlet air flows.

Lots of people have spent lots of time, trying to improve this aspect. There were some 3K engines with bigger inlet valves, which is why I asked you previously, to give us the number of the head on you 3K.  Lots of people have experimented with head swaps, to get compression ratios up around 10:1.  It is generally agreed that anything above 10.5:1 is counter productive.

I picked up a 5K engine here in Qld. a couple of years ago, for $ 100,which was an ex dirt track sprinter car engine.  They were very popular years ago, in this realm, & quite reliable. One rainy day, I'll get it going again. It has some flash improvements, including a very fancy oil pump arrangement.

Have a read in the WiKi on this forum, & there are plenty of threads, where all sorts of people, who love K Series engines, have tried all sorts of things, to get a bit more grunt, out of these engines. Luke, keep the questions coming, & we'll assist if possible.  Where are you located ?

Cheers Banjo

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Yep cyl 4 was the culprit - and I think you're spot on about cyl 4, there was a loss of power occasionally particularly on hotter days -  I thought i had a sticking caliper.

Truthfully i wasn't paying as much attention as i should of to the Ke30 as i was rebuilding a 12r for my 1973 corona and was expecting it to just survive on basic servicing.

I'll definitely get the number for you Banjo, and i'll be doing homework on everything k engine - noted about the 4k as well guys I'll still look at this one this weekend just cause it's already arranged - it might be a good get of jail for the short term or I'll learn the hard way 😂.  At the very least i can do all the work myself and not worry as it's not the original motor.

 

100 is a great price, i live in the Dandenong ranges in Victoria - If anyone knows the area they'll know why i have issues with hills

much appreciated all the help everyone, if anyone wants to give me their tips on seating new pistons & rings while we're at it i'll happily take them - that's what i'm doing on sunday! 

 

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There's only one astounding 4K conversion.. This one!

But it shows that you can bore a 4K block out 6mm!! Lighten & knife-edge the crank, fit a 4AGE head and pull 9000rpm!   That block is tough!

 

As for running a motor in, I reckon get it running and take it driving, just general driving without letting the revs drop low enough to make it lug, or booting it so its pulling max power up into the rev range... just keep it lightly loaded driving around for half an hour while you watch the temp gauge. Then again, in South Africa Toyota took the cars off the end of the assembly line straight to the dyno room and ran them briefly at full power before parking them.  Who knows?

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Hi Luke,

             Are these pistons & rings going into a rebored block ?  Spend lots of time getting your ring gaps correct, by placing the rings in the bore, & squaring then in the bore with a piston pushed down upside down, to normal piston orientation.

http://blog.wiseco.com/everything-you-need-to-know-about-ring-gap

If the bore hasn't been freshly bored, then make sure any existing lip at the very top of the bore ,is removed where ring does not sweep the bore. Not removing it, risks losing your new top rings.

Arh, the legendary 3KR motor !                   https://www.rollaclub.com/board/topic/17848-3kr/

Here's one in full flight . . .       https://www.youtube.com/watch?v=BCwYxmbPaWY    (yes, He does get past him, in the end ! )

 

Cheers Banjo

 

 

Edited by Banjo
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Hi Luke,

             

Quote

just keep it lightly loaded driving around for half an hour while you watch the temp gauge.

I tend to agree with Keith very much on this one.  A newly, fully or partly reconditioned engine's, "first hours of waking life", can be crucial to it'd longevity, as a reliable engine.

It's all about engine temperature, tolerances, & oil viscosity. My dash temp & oil guage are the most important instruments in my Rolla.

image.png.c6c4ef8c11e763ead817fe99edb24429.png

There are some really good general rules. Never ever start "revving the guts" out of a newly started motor, once it kicks over for the first time.  It is human nature, & an expression, of human emotion, & sense of achievement, to want to "give it a burl", but it can be counter productive in the long run.  Let it idle, & even cover the radiator, to get it up to temperature, as quickly as possible.  Try not to load the engine for  at least 30 minutes. Never put a very high viscosity oil in a newly refurbed engine initially.

After several hours of running; & only when the engine is definitely at operating temperature; you should drain the oil & change the filter. You'd be surprised how much initial "wearing" in of metalic surfaces, takes place during that "running in" period.

Same suggestion for the coolant system. However, that can be done after a good week of driving.  Take hoses off & really drain it; not just using the tap at the bottom of the radiator.  You'd be surprised at the little bits of crud & gasket cement & the like that comes out.  Keith suggests watching that temperature guage.  This is really important.  These engines are designed to run between 80-90 deg C. 

Taxi's get such incredible long lives out of their engines, because they rarely ever get cold; sometimes running 16 - 24 hours a day, & just changing drivers at change of shift.  I may be olde school, but I still take my wife's Corolla out of the garage each morning, & leave it idling in the driveway for 10-12 minutes, before she leaves for the daily commute, to work.  This is really important in winter. 

I've heard it said, by professionals, that more wear takes place in an engine in the first couple of kilometres driven each day, than the wear that takes place for the complete rest of the day's driving.

I have a good friend that lives in the Yukon, up near the polar areas, north of Canada, where it is extremely cold, & there is permafrost.  They have permanent electric heaters in the sumps of their vehicles, & they plug them into the power point in the garage every night, so the engine can actually turn over in the morning, & drive away initially, without any substantial engine lubricant protection, because the high pressure bypass valve opens, & dumps a substantial amount of oil straight back into the sump. 

P.S.  Regarding your issue with cylinder number 4, you might like to take a look & read these long threads on here, where a few of us, have shared our thoughts, on this perennial issue with K series engines.

https://www.rollaclub.com/board/topic/73676-oil-pump-failure/page/8/?tab=comments#comment-713644

https://www.rollaclub.com/board/topic/77718-radiatorcooling-help/#comments

Cheers Banjo

 

 

Edited by Banjo
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