JP4 head conversion - What's needed?

[aruffell]

Right, my oil leak is starting to get on my wick and my 206 1.6 16v head has been sitting in my shed for some time now.

So question is, what do i need to hand it all over to KrisB with?

I've got the head, and i can let him take my cams and valve springs out of mine to put into it.

I'm also on the understanding that it needs skimming.

What else will i need? Head gasket to compensate for the skimming? Anything else?

Head bolts?

Thanks,

Andy

[Mr_P]

Doesn't need skimming. Unless of course, yours is warped.

You wanna use the JP4 headgasket.

If he's swapping the springs and cams around It might be worth replacing the stem seals whilst he's there depending on the age of the head. New camshaft seals.

New head bolts. The J4 pulleys...

That's pretty much all I can think of.

What rocker covers are you using?

[aruffell]

I was told it should be skimmed (I got the head from a breakers).

Doesn't having a skimmed head give better performance too?

Camshaft and stem seals - Rough pricing?
Jp4 headgasket? Rough pricing?
Best place to get head bolts?

So when he takes the cams out of my J4 head, it should take the pulleys too?

Thanks for the quick reply, and i'll be using the JP4 rockers too, just need to find the breather hoses as it didn't come with it for mine and Citroen want £40 or so i believe.

Andy

[Mr_P]

I was told it should be skimmed (I got the head from a breakers).

Doesn't having a skimmed head give better performance too?

You only need to skim a head if it no longer has a flat mating face. Which will prevent the headgasket from sealing probably.

Getting it skimmed for piece of mind is fine.



Camshaft and stem seals - Rough pricing?
Jp4 headgasket? Rough pricing?
Best place to get head bolts?




Camshaft and stem seals - Rough pricing? 20+ quid ish
Jp4 headgasket? Rough pricing? 40+ quid ish
Best place to get head bolts? Motor factors.




Yerh take the pulleys too. Don't think the JP4 ones are adjustable are they? Mine weren't anyway.

[Olly]

cambelt, and tensioner/waterpump pending condition/age/mileage of the old ones deffo cambelt though.

new camshaft seals

[aruffell]

I've got a cambelt and tensioner kit for my J4, is that the right one, or will i need the JP4 one? I'm guessing the one i've got is fine if i'm using my pulleys from my J4 head.

Could get a waterpump though, rough pricing?

Andy

[Olly]

water pump 20-30 quid from a motorfactors

J4 will be fine pulley and belt etc wise.

[aruffell]

I will probably get the head skimmed for peace of mind, but i hear sometimes people at car meets going on about having a skimmed head, and i know my current J4 head is skimmed as well as being port and polished.

Does skimming it actually make a performance difference? If not, how comes people do it to their cars and make it sound as if it's been done for an increase?

Andy

[Finchowned]

Anyone done any definitive back to back testing with the J4 and JP4 heads?

[adamskiTNR]

It depends how much they have skimmed off. If it's just to recondition the face then the increase will be minimal, but if they have taken a fair slice off then the compression ratio will increase, giving greater performance but more engine knock etc etc.

[Mr_P]

I will probably get the head skimmed for peace of mind, but i hear sometimes people at car meets going on about having a skimmed head, and i know my current J4 head is skimmed as well as being port and polished.

Does skimming it actually make a performance difference? If not, how comes people do it to their cars and make it sound as if it's been done for an increase?

Andy



If you skim the head. You use a repair headgasket to make up for the difference.

So it makes absolutely no difference whatsoever. It's just to ensure a good seal between the head and the block.

If you skim the head and use the standard headgasket then you will be raising compression ratio. But by such a tiny amount it won't give you any performance gain. The only thing you'll be increasing is the likelihood of your pistons slamming into your valves.

Skimming the head is NOT a performance upgrade. A ported head, yes.

[aruffell]

Ok, i may just get them to skim the very minimum then to give peace of mind, would you still use the standard jp4 gasket if it's the minimum they take off?

Andy

[Mr_P]

Ok, i may just get them to skim the very minimum then to give peace of mind, would you still use the standard jp4 gasket if it's the minimum they take off?

Andy


Standard jp4 gasket is 0.6mm.

If you get 0.2mm skimmed. get a 0.8mm gasket.