Race Engine !!!!!!

[Trev]

Go for a 5k, why spend money increasing the capacity of a 4k when a 5k is 200cc bigger to start with?

 

I am saying to keep it the same bore/stroke.

[altezzaclub]

Got a budget in mind??

 

$10grand? 20grand? 30grand??

 

If you haven't got at least $10grand lined up then forget it! Restore it as a nice road car and use it as a weekend warrior.

 

Even doing all the work yourself racing can swallow $10k before you even hit the track, so fix the body, suspension & brakes, get it road-registered and run the stock 4K for 6months while you amass a stack of money and parts.

 

At least that way you're driving it and having fun rather than working on an impossible project that drags on for years... (speaking from experience!)

[jimi91]

Got a budget in mind??

 

$10grand? 20grand? 30grand??

 

If you haven't got at least $10grand lined up then forget it! Restore it as a nice road car and use it as a weekend warrior.

 

Even doing all the work yourself racing can swallow $10k before you even hit the track, so fix the body, suspension & brakes, get it road-registered and run the stock 4K for 6months while you amass a stack of money and parts.

 

At least that way you're driving it and having fun rather than working on an impossible project that drags on for years... (speaking from experience!)

 

 

yeah thats what i was thinking of doing maybe if the engine is to much cause i want to do an upright engine as well i might have to save up heaps for the engine and extra parts so i might do that then !!! :blush: my budget would prob be around 10k with all the body and suspension stuff, rego, insurance etc etc lol

 

yeah i thought the stroke should be fine but bigger bore might be better idk yet ill have to look into it and figure out ratios and stuff??? :hmm:

Edited November 17, 2010 by jimi91

[LXY-642]

spool do forged rods. $550 a set i think the price is.

 

i can see this being a very expensive build. and personally, i'd rather buy an xr6 turbo ute then spend the same amount on a k motor :P

[jimi91]

spool do forged rods. $550 a set i think the price is.

 

i can see this being a very expensive build. and personally, i'd rather buy an xr6 turbo ute then spend the same amount on a k motor :P

 

 

hahha yeah i will do forged rods but just standard k size, hahahah yeah true mate but ya can't beat the character of a rolla mate and the sound of a nice k engine revving its tits of lol :laff: idc about if its faster then a turbo or that i just want it to go great and sound good and have fun with it i may spend 10k on it but so what its my money and it will be a sweet ride when I'm done :wink:

 

see ya

 

jimi

[Des]

If i was in your shoes id be running Ae71 brakes up front and probably leave the rear drums alone, front to rear proportion may be out though.

 

Do Ke17's still run the transverse leaf in the front ? If so run ke20 springs and ke20 strut tops on the 17 struts. Run what ever insert you choose and what ever spring rate you like. Reset the rear leafs, add leafs and run dampers of you choice. Ke30 inserts should fit the front struts with a spacer.

 

Insert $100 4k and flog the shit out of it and when if it pops buy another. Run some wide 13 inch rims with decent tread.

 

If your serious about circuit racing i doubt you will keeping a K motor for very long so i wouldn't spend a heap on one. That's what i would do for fun if i was in your shoes.

[Hiro Protagonist]

Sorry GJM, I accidently hit neg rep while scrolling down.

 

If it was me, I'd go 4k unless, the 5k is a torque motor and you wanna add to that by putting bigger pistons in it, bore = torque, stroke = horsepower.

 

Wrong way around - oversquare (ie bore bigger than stroke) is generally for high-rpm power, undersquare (stroke bigger than bore) is for low-rpm torque. A 5K is a bored 4K (they use the same crank and thus have the same stroke), and thus the 5K tends to rev better than the 4K. Naturally it will make more torque because it is making more power (the two are fundamentally linked), but it will probably make less torque than a similar capacity motor but with undersquare dimensions.

 

In short, a 5K is better than a 4K in just about every way (especially for hotting up) except _maybe_ fuel consumption, but who cares about that anyway :P

[philbey]

I say build this engine, spend a shitload, make a bunch of horsepower that still wont beat your mums falcon. Enjoy every moment when you fire up this thing and it's lumpy, so lumpy, on idle it froths up your beer and scares grannies when you drive past 'em and they drop their shopping.

 

why 5k tho wats the dif between them and most race corollas have been 4k so why not stick with the rest ?????

 

Most race corolla's are running the 4K because of the class restriction, not because they're better than a 5K.

 

 

 

Go for a 5k, why spend money increasing the capacity of a 4k when a 5k is 200cc bigger to start with?

 

Have a good read of this article you will find some good starting tips there.

 

Sensible point doogs, puttin 80+mm pistons into a 4K just turns it into a 5k of sorts

 

yeah thats what i was thinking of doing maybe if the engine is to much cause i want to do an upright engine as well i might have to save up heaps for the engine and extra parts so i might do that then !!! :blush: my budget would prob be around 10k with all the body and suspension stuff, rego, insurance etc etc lol

 

I suggest you just build the motor on a slant. I built mine with the dellorto's for about 2000, tuned. A very rare upright kit just sold on here for 1000 bucks! You wont see huge gains from uprighting and there's and you can always upgrade the motor later on. The biggest gain is found in space in the engine bay, it's difficult getting air cleaners to fit on sidedraft carbies in a Ke1x engine bay. Look at my pics.

 

hahha yeah i will do forged rods but just standard k size, hahahah yeah true mate but ya can't beat the character of a rolla mate and the sound of a nice k engine revving its tits of lol :laff: idc about if its faster then a turbo or that i just want it to go great and sound good and have fun with it i may spend 10k on it but so what its my money and it will be a sweet ride when I'm done :wink:

 

Good attitude, build what you want, spend what you can, forget the "do the body first" "do the brakes" bullshit. You asked about building a race motor, not "what should I do to my car first". You can do brakes and suspension while you wait for your engine to come back from the machinist.

 

My car handles like shit, but it screams. And now I fixed the oil leak, I love it again.

 

Don't bother with things like forged rods, 400 bucks you can spend elsewher. If you're really serious though you could regrind the crank to stroke it. Nobody ever talks about K engine cranks breaking.

 

Spend the money on balancing it so it revs. Get a dirty great big cam, dial up the compression, spend 500 bucks on getting the head to breathe better, slap on twin sidedrafts rip skids, axle tramp, make noise, upset neighbours, freak out some squares!

Edited November 18, 2010 by philbey

[Trev]

Wrong way around - oversquare (ie bore bigger than stroke) is generally for high-rpm power, undersquare (stroke bigger than bore) is for low-rpm torque. A 5K is a bored 4K (they use the same crank and thus have the same stroke), and thus the 5K tends to rev better than the 4K. Naturally it will make more torque because it is making more power (the two are fundamentally linked), but it will probably make less torque than a similar capacity motor but with undersquare dimensions.

 

In short, a 5K is better than a 4K in just about every way (especially for hotting up) except _maybe_ fuel consumption, but who cares about that anyway :P

 

You do know that the bigger the over square is the less they rev?

 

Who wants a race engine that will only rev to about 6500?

[LittleRedSpirit]

You should have bought TRD ke70s motor, it was pretty full house as K motors go! :happy:

[Hiro Protagonist]

You do know that the bigger the over square is the less they rev?

 

Who wants a race engine that will only rev to about 6500?

 

Remind me to tell F1 engineers that their engines can't rev because they're too oversquare (often up to 2.5:1 bore-to-stroke ratio). Using K motors as an example, the 4K is roughly square, the 5K is oversquare (basically a bored-out 4K) and revs better, and the 7K is undersquare (basically a stroked 5K) and makes better low-down torque (hence its use as a forklift and van engine).

[Trev]

Remind me to tell F1 engineers that their engines can't rev because they're too oversquare (often up to 2.5:1 bore-to-stroke ratio). Using K motors as an example, the 4K is roughly square, the 5K is oversquare (basically a bored-out 4K) and revs better, and the 7K is undersquare (basically a stroked 5K) and makes better low-down torque (hence its use as a forklift and van engine).

 

f@$king total blonde moment in the whole thread, after you said that I remembered the 4k vs 5k thread where I even said my bike revs well because of over square.

 

Why my bike revs to over 18'000rpm :D

 

Bore x stroke: 48.0 x 34.5 mm

 

http://www.rollaclub.com/board/topic/39828-4k-vs-5k-dispute/

 

carry on.

[jimi91]

If i was in your shoes id be running Ae71 brakes up front and probably leave the rear drums alone, front to rear proportion may be out though.

 

Do Ke17's still run the transverse leaf in the front ? If so run ke20 springs and ke20 strut tops on the 17 struts. Run what ever insert you choose and what ever spring rate you like. Reset the rear leafs, add leafs and run dampers of you choice. Ke30 inserts should fit the front struts with a spacer.

 

Insert $100 4k and flog the shit out of it and when if it pops buy another. Run some wide 13 inch rims with decent tread.

 

If your serious about circuit racing i doubt you will keeping a K motor for very long so i wouldn't spend a heap on one. That's what i would do for fun if i was in your shoes.

 

 

yeah i think the 17's do still have the transverse leaf front end????? so thats why i might have to change crossmembers or mod diff struts to suit, will a bigger sway bar help my handling???? yeah i will do the rear leafs and maybe stiff dampers or something yeah i might do that as well. yeah thats what ill do know and build and save money while i drive it around and that and yeah ive already got some nice mags on it have a look :lolcry:

 

 

Wrong way around - oversquare (ie bore bigger than stroke) is generally for high-rpm power, undersquare (stroke bigger than bore) is for low-rpm torque. A 5K is a bored 4K (they use the same crank and thus have the same stroke), and thus the 5K tends to rev better than the 4K. Naturally it will make more torque because it is making more power (the two are fundamentally linked), but it will probably make less torque than a similar capacity motor but with undersquare dimensions.

 

In short, a 5K is better than a 4K in just about every way (especially for hotting up) except _maybe_ fuel consumption, but who cares about that anyway :P

hahahah yeah thanks thats what i couldnt understand the diff but thanks it makes sence I'm not to worried about econ mate i have webbers so there will be no such thing lol :blinks:

 

I say build this engine, spend a shitload, make a bunch of horsepower that still wont beat your mums falcon. Enjoy every moment when you fire up this thing and it's lumpy, so lumpy, on idle it froths up your beer and scares grannies when you drive past 'em and they drop their shopping.

 

hahahha yep thats what i want idc if it doesnt beat a holden and that it will go fast for a rolla and sound awsomne at lights lol

 

Most race corolla's are running the 4K because of the class restriction, not because they're better than a 5K.

 

yeah true that :hmm:

 

 

 

Sensible point doogs, puttin 80+mm pistons into a 4K just turns it into a 5k of sorts

 

so does that mean 83mm would be a good size in a 5k block

 

I suggest you just build the motor on a slant. I built mine with the dellorto's for about 2000, tuned. A very rare upright kit just sold on here for 1000 bucks! You wont see huge gains from uprighting and there's and you can always upgrade the motor later on. The biggest gain is found in space in the engine bay, it's difficult getting air cleaners to fit on sidedraft carbies in a Ke1x engine bay. Look at my pics.

 

hahah thanks but i still want to do it just to be different and for a challenge thanks anyway mate

 

Good attitude, build what you want, spend what you can, forget the "do the body first" "do the brakes" bullshit. You asked about building a race motor, not "what should I do to my car first". You can do brakes and suspension while you wait for your engine to come back from the machinist.

 

yeah thats what i mean, thats what i was going to do while the engine is off or I'm waiting for bits i can work on the body and do other stuff thanks mate :happy:

 

My car handles like shit, but it screams. And now I fixed the oil leak, I love it again.

 

Don't bother with things like forged rods, 400 bucks you can spend elsewher. If you're really serious though you could regrind the crank to stroke it. Nobody ever talks about K engine cranks breaking.

 

yeah i thought that to so ill see how i go but cheers

 

Spend the money on balancing it so it revs. Get a dirty great big cam, dial up the compression, spend 500 bucks on getting the head to breathe better, slap on twin sidedrafts rip skids, axle tramp, make noise, upset neighbours, freak out some squares!

 

hahahahha yep exactly what i want to do and come on who doesnt like a sick as rolla that looks and goes tuff as lol :laff:

 

You do know that the bigger the over square is the less they rev?

 

Who wants a race engine that will only rev to about 6500?

 

I'm pretty sure if i do the engine the right way it will rev better then that :hmm:

 

You should have bought TRD ke70s motor, it was pretty full house as K motors go! :happy:

 

hahahah i wish mate :lolcry:

 

Remind me to tell F1 engineers that their engines can't rev because they're too oversquare (often up to 2.5:1 bore-to-stroke ratio). Using K motors as an example, the 4K is roughly square, the 5K is oversquare (basically a bored-out 4K) and revs better, and the 7K is undersquare (basically a stroked 5K) and makes better low-down torque (hence its use as a forklift and van engine).

 

yeah so maybe a 5k is better for a race engine then hmmm :hmm:

[Felix]

Get the thing on the road first, then start putting the dreams into reality. Maybe do a bit of research in the time being....

 

Best thing to do is to do things in stages. A ke1x will bite you in the ass a lot quicker than any later model if you f@$k up behind the wheel when pushing the boundaries. Drive it stock, learn it's limits, update bits, relearn limits, rinse and repeat.

Edited November 18, 2010 by Felix

[jimi91]

yeah i might do that thanks mate

 

see ya

 

jimi