Bore'ing Out A 4k

[trav_555]

thats a 5k bored to 4age, a 4k needs alot more boring just to get it to a 5k

[KE30_KE35_KE55]

thats a 5k bored to 4age, a 4k needs alot more boring just to get it to a 5k

 

Don't take the chance, bore it out and fit 4 thick dry sleeves you will know you have lots of steel in the wall. They cost about $50 each

[trav_555]

never heard of those?

 

so you bore it out extra and fit the sleeves?

[KE30_KE35_KE55]

never heard of those?

 

so you bore it out extra and fit the sleeves?

 

yes they leave a ridge in the bottom of the old bore so the sleeve doesn't fall down, the sleeves are bored to be a interference fit. they are cut off at the top.

then the face of the block will be machined. i have done my own but probably best to get it done at a engine reconditoner.

[Falken_KE30]

Oh....Me, me, me! *pushes flush button*

 

Darn... i wanted to flush it... care to put head in toilet again Teddy? :)

[rob83ke70]

I'm suddenly having strange urges to flush my head in the toilet too.... I wonder why that could be?

 

In the grand scheme of things boring your engine out will make a neglible difference and will cost you more that what it is worth. The things that make the biggest difference are camshaft profile, cylinder compression, and how big your sparks are. You also need the gasses to flow smoothly with high velocity in and out of your engine. You need to have everything set up right to make your engine run its best.

 

I really thing that you need to get yourself into a non collectable non toyota car that goes reasonably well so when you slow it down by modifying it the performance loss won't be crippling.

[trd]

my bro bored a 4k out to 5k (80.5) so it can be done. BUT you need the right block its a commercial block with siemze bores. if its a ke70 put a 5k in it - i know qld transport have in there book something saying" if the car was factory fitted with that engine you don't need a mod plate" ke70's were fitted with 5k's in japan. i don't know about the rest of the country but could be the same.

[trav_555]

I'm in nsw, don't think that applies here

 

its like 10cc out

 

i already have done what you said rob83ke70 :)

 

just wanted more displacement so wanted to look into this ;)

[KE30_KE35_KE55]

I'm suddenly having strange urges to flush my head in the toilet

 

don't get your head stuck

 

You could drown.

[trav_555]

haha, well my headss spinning with imformation, i think I'm going to have to have a long hard look into this before i even dream ;)

[the_random_hero]

Wait till your off P's, buy a car/engine that's fast in the first place. You'd get what, maybe a 10HP increase for a LOT of money? IMO, there are MUCH better and easier mods to make with bigger power gains.

[trav_555]

would it really only be ten hp?

 

i thought it would be more ;)

 

more torque though?

 

any imput from others whove done this?

[tas_ae71]

well what sort of carb/s would you be running??

 

i say spend your dosh on susy, wheels etc.. you can make them a lot faster by adding susy as you don't haev to slow down as much ;).

 

add to the a t-series and lsd. then you could start collecting parts for a 4ag conversion.. by then you would prob be near off your P's.. or as you said buy a s13 if you so keen on them lol.

[trav_555]

i will be runing 7k efi

 

yea sussy and wheels are def next

 

s13 for second daily might be the go, bit of fun. + i need a second car for when this goes off the road at times, and don't want to drive the same type of car, want something different to have a go with

[TRD ke70]

Yes boring out a 4k to 81-83mm is possible but the stress on the block is quite high, this why the 5k block( and also the 7k) has extra strengthening.

if you're going to put 4AGE pistons into it you'll need to work out what pistons you need, as the 4k con-rod has a 18mm pin, but most 4age's have the 20mm pin, early 4age's did have the 18mm pin, these are the weak link, you could bore the little end of the con-rod out to take the 20mm pin, but it could weaken the con-rod.

also if you're planning to screw good HP out of the engine, there is a good chance of splitting the bore or cracking the block.

if you want to enlarge the engine, put a 5k into it and re-number the block, or even better a 7k.

 

good luck.