Valve, Head Cleanup

[Twinky]

Cool! I'll try to find someone here in Adelaide that could do it for me now. Anyone recomend a place in the mid north?

[philbey]

TW Engineering port matched my head to my inlet manifold, opened it up to about 33mm.

 

Unit D/ 140 Tolley Rd St Agnes SA 5097 - (08) 8263 6311

[Twinky]

Cheers. Rang him and got a quote for "a couple of hundred dollars" at which point I had this feeling that someone had punched me in the goolies.

Gunna see if I can set up some machines at work and do it myself....

[philbey]

Do you want to do it properly or do you want to just make them bigger so you sleep better at night?

 

Because TW will flow it and port it properly for that couple of hundred dollars.

[Twinky]

At the moment I can't justify spending a couple of hundred dollars on a k engine that would otherwise cost $100 to buy.

I was initialy thinking it might cost $150 - $200ish which I would have been happy with. For the same cost I could buy a performance camshaft for the 4k....

I have recently become a homeowner so my spending mula has become somewhat limited. I still have another beastie to spend about $800

to get it track ready again for the next mallala meet.

 

Anyhows I have noticed something else which leads me to believe that I do not have a bigport. I took another manifold off of a different 4k at the wrekers

and it had the same port missmatch on the intake runners. Did toyota do this intentionaly?

 

I'm going to do some more hunting around before I make my decision at the moment.

[Trev]

At the moment I can't justify spending a couple of hundred dollars on a k engine that would otherwise cost $100 to buy.

I was initialy thinking it might cost $150 - $200ish which I would have been happy with. For the same cost I could buy a performance camshaft for the 4k....

I have recently become a homeowner so my spending mula has become somewhat limited. I still have another beastie to spend about $800

to get it track ready again for the next mallala meet.

 

Anyhows I have noticed something else which leads me to believe that I do not have a bigport. I took another manifold off of a different 4k at the wrekers

and it had the same port missmatch on the intake runners. Did toyota do this intentionaly?

I'm going to do some more hunting around before I make my decision at the moment.

 

Not just toyota, almost all manufacturers did this.

[snot35]

Factor in that these are old cars, engines and ancillaries are changed quite often. Mechanics can put anything on if the customer knows no better and they have something handy.

 

I tried to register my 30 and found that the engine in it had been stolen at some stage!

 

Those ports look big. People have verified they're big. If you're able to find the matching manifold then that would be a good thing. But, you're on a budget, so run what you've brung. From my limited knowledge of porting so far, I'd say those ports are definitely big enough for the valves you probably have in that head. If you're keen you could spend the money on a burr, grab your power drill and smooth out any sharp edges in the port. Beyond that it's going to cost you a bit. That's all there is to it!

[Twinky]

Not just toyota, almost all manufacturers did this.

 

Yeah but this is a difference in 3mm! Must have been rough times in toyota for this cost cutting excersize.

[Twinky]

Factor in that these are old cars, engines and ancillaries are changed quite often. Mechanics can put anything on if the customer knows no better and they have something handy.

 

I tried to register my 30 and found that the engine in it had been stolen at some stage!

 

Those ports look big. People have verified they're big. If you're able to find the matching manifold then that would be a good thing. But, you're on a budget, so run what you've brung. From my limited knowledge of porting so far, I'd say those ports are definitely big enough for the valves you probably have in that head. If you're keen you could spend the money on a burr, grab your power drill and smooth out any sharp edges in the port. Beyond that it's going to cost you a bit. That's all there is to it!

 

 

I've got a spare manifold that I might try to port myself and see how it turns out. It could be an interesting experience and hopefully a successful one.

Apart from that i might actually have a go at getting the bike carbies to work with the motor as they have the same port sizes as the head which will make life easier.

 

At this stage i'm going to focus on finishing the head clean and decide what to do when I get to that bridge after some thought.

 

Valve lapping tools are so overated..... I could have used a lump of blue tack and a stick and it would have worked better. Just that the tools suction cap was either too big or too small at the ends.

It still worked but kept on poping off too easily.

[Taz_Rx]

Trust me, that is a 3k big port head. Somebody has obviously put the 3kbp head on a 4k bottom end (did you check the BLOCK engine number?) but just used the 4k intake manifold and carby on it. This explains why the manifold ports are smaller.

[Twinky]

Trust me, that is a 3k big port head. Somebody has obviously put the 3kbp head on a 4k bottom end (did you check the BLOCK engine number?) but just used the 4k intake manifold and carby on it. This explains why the manifold ports are smaller.

 

I checked the head number and the first part of the serial is the same as the 3kbp but the final 3 numbers are different. I have posted the number on page 2 of this thread.

I have not cheked the block number yet.

The other manifold (spare) has the same port missmatch markings on it from the other motor in the wreking yard. So basically another 4k in the wreking yard had the same port missmatch as mine.

I havent measured it's port sizes tho. If anyone can confirm the 3kbp port sizes that would be helpful. My intake port sizes on the head are 32mm.

on another note are the 3kbp ports any bigger than standard 4k ports?

[Taz_Rx]

You're not listening. TRUST ME (i'm not a tech mod for nothing) THAT IS A 3KBP head. This is identifiable for several reason as already covered.

1, the fact it has big ports

2, The welded up welsh plug in the back

3, the shitty old valve stem seals

4, the casting number in the head... regardless of what they are.

 

Yes 3kbp's have bigger ports than 4k's (they wouldn't be called big ports otherwise). From memory the 3kpb ports are 32-33mm and 4k ones are 27-28mm.

[Trev]

You're not listening. TRUST ME (i'm not a tech mod for nothing) THAT IS A 3KBP head. This is identifiable for several reason as already covered.

1, the fact it has big ports

2, The welded up welsh plug in the back

3, the shitty old valve stem seals

4, the casting number in the head... regardless of what they are.

 

Yes 3kbp's have bigger ports than 4k's (they wouldn't be called big ports otherwise). From memory the 3kpb ports are 32-33mm and 4k ones are 27-28mm.

 

What would you know Simon :bash: :bash:

[Twinky]

I think my confusion must be coming from the fact that another motor had the same issue as I have therefore making me think that all 4k's had this problem.

It could be that I may have found another 3kbp head at the wreckers! Unfortunately I can't rip it off as they have done a crush recently.

Just for my own satisfaction I'm going to go down to the wreckers and measure port sizes. I'm kind of like a glass half empty person that will only believe what

I read until I see it for myself. I have made mistakes in the past by listening to knowledgable people. I'm not saying that anyone here does not know

what they are talking about but like snot35 said alot of these old cars have had all kinds of things done to them and everything is almost like a case by case issue.

I'm sitting on about %90 confidence that I have a 3kbp head from those said facts but like I said I want to be %100 sure.

 

Cheers for all your input and patience with me. My brain moves faster than my typing so I can never explain things properly.

[Felix]

Listen to Taz.

 

3k bigports have the casting number prefix 24010 - xxx

k bigports have the casting number prefix 22010- xxx

 

All later heads seem to have random numbers cast on them.

 

The 3k bigport heads were standard on late ke1x through the ke2x series. Then actual endpoint/changover to the small ports I'm not exactly sure of.