Hi there,

Does anybody know if there is enough meat in a 4K block to bore it out to take 5K 80.5mm pistons? I know you can go to 79mm no problem. This would save me having to carve up a block to see.

Also have a supercharger that I was going to try a suck through system on, has anybody tried this?

Thanks Dobsy

Yes many people have had draw-thru supercharger setups on K engines...Why don't you just find a 5K? Might be easier

5k are hard to find in NZ & you then have to convert to non hydrolic lifters etc. I already have loads of 4k bits so it's just laziness I guess.

Fair enough

You could allways bore out huge and fit 4 thick dry sleeves.

a normal 4K out of say a KE70 you can't bore out to fit 5K ones and have it reliable. Bore walls are as thin as paper.

 

BUT the industrial 4K found in fork lifts van etc have thicker bores and YES can be bored out to take 5K pistons.

 

also if you run a SC14/12 with draw through can be done works great :fuzz: BUT they weren't initially designed for fuel to also go through them. The extra fuel is and does over time wear the blower rotor clearance and they will be less efficient and not pump as much air. But it still works and for most cases you wont notice that. But when pushing them to about 13/14PSI draw through the loss and wear the fuel creates will start to be noticed after a few KM have racked up. Also the best efficiency of a SC14 blower is at 8PSI. I plan to run mine there with draw through. At this pressure the blowers are efficacy and less heat is made o air is cooler so wont need a inter cooler and with draw through you can't run an inter cooler so I can't really go all out on the boost.

 

But with boost personally Id prefer thicker bores and if you find a 5K easy get 3F Toyota motor lifters and use dished piston 4K push rods easy :bash: But if you run a 3K head you will need chev lifters and datto A12 push rods.

 

Cheers

Cameron

I hav a 3K engine I'm building, i bored it out 3.5mm and I'm using TX3 Turbo pistons with a suckthru SC14 setup (10psi) with a 1 and 3/4 SU etc. I work at a decent engine building shop, and did all the machining myself, you'd be surprised how thick 3K bores are before you hit water.

 

Cheers Trentuss

4k commercial (van) engines also have a thicker bore, i have bored a 4k to 5k before with no problems.

 

one thing i did strike is the guy boring thought i was nuts.

I'm guessing the SC14/12 is a roots type blower with the counter turning spools?

^Correct.

Do you know how to tell a van block from a car one?