186 head on a 202? ( red )

[V3N0M]

been told by a few people now to put a 186 head on my red 202 in my vb.. what would that do exactly?

[Shifty1]

it will raise the compression in your engine

[V3N0M]

lol thats good right :P (my dad was the mechanic and unfortunetly didnt get the chance to teach me lol )

[Shifty1]

if its on lpg it is as high compression is more power output on lpg... otherwise on petrol i dont know how much of a benefit you'd get..

[V3N0M]

oh ok yeah it dosnt run on lpg.. just normal petrol.. thanks ^_^

[craigvk]

oh ok yeah it dosnt run on lpg.. just normal petrol.. thanks ^_^

What do you call normal petrol? My mate has some 30 year old standard out the back. Bung that in and it might take off like a rocket.

[craigvk]

I'm not joking either. About the standard.

[Cane_It]

the standard will be stale, it goes off and after 30 years... old mate put a heavily modified 149 head on a 186, this was back in the leaded days befoer the shit they pass off as petrol now though, thing had an easy 10:1 comp.

[V3N0M]

lol normal as in just that premium unleaded crap that u have to put the additive in.. so puttin a 186 head on my red 202 would be worth it? is it a simple bult on or do i need to do mods?

[Cane_It]

lol normal as in just that premium unleaded crap that u have to put the additive in.. so puttin a 186 head on my red 202 would be worth it? is it a simple bult on or do i need to do mods?

will go straight on, only thing to check is how much the head has been shaved and whether theres a difference in the ports between red and blue heads as this could affect manifold choice. look for a letter "H" cast into the head on the manifold side about 2/3rds of the way back, this denotes hgh compression which will mean a smalled "closed" combustion chamber, if i were you I'd try and find a yella terra head second hand from a swapmeet or something thats already got the big valves and mild porting. you'll need to check valve to piston clearance using some plasticene on the pistons during a dummy assembly and turning the motor over by hand, most important if youre gonna upgrade the cam.
also check the head and block faces for warping (straight edge and feeler gauges) this is critical or the head gasket wont seal and you'll have low compression and possible coolant leakage.
coat the head gasket in an aluminium rich paint before installing wil help if theres some deck or head face warpage but within spec, this helped me get away with not stripping the motor and getting the devk faced when i was 17.

sorry for the essay, hopefully some of this helps ya. think carefully about going high comp, you'll need to always run octane boost or PULP or back the timig off which defeats the purpose anyway.

[craigvk]

the standard will be stale, it goes off and after 30 years...

hehe. Yeah. After 12 months probably

[Dan355]

will go straight on, only thing to check is how much the head has been shaved and whether theres a difference in the ports between red and blue heads as this could affect manifold choice. look for a letter "H" cast into the head on the manifold side about 2/3rds of the way back, this denotes hgh compression which will mean a smalled "closed" combustion chamber, if i were you I'd try and find a yella terra head second hand from a swapmeet or something thats already got the big valves and mild porting. you'll need to check valve to piston clearance using some plasticene on the pistons during a dummy assembly and turning the motor over by hand, most important if youre gonna upgrade the cam.
also check the head and block faces for warping (straight edge and feeler gauges) this is critical or the head gasket wont seal and you'll have low compression and possible coolant leakage.
coat the head gasket in an aluminium rich paint before installing wil help if theres some deck or head face warpage but within spec, this helped me get away with not stripping the motor and getting the devk faced when i was 17.

sorry for the essay, hopefully some of this helps ya. think carefully about going high comp, you'll need to always run octane boost or PULP or back the timig off which defeats the purpose anyway.

There is a difference between 202 and 186 heads/blocks.
Firstly the water gallaries are different so youll need to block some gallary holes and drill some new ones to line up with the ones in the head. If not the thing will over heat. Best way to do this is to use the head gasket as a template. Use 1/2" 3/16 bsw Grub Screws by memory but youl need to tap the holes you are blocking.
2nd the ports are different on the heads this also includes head stud location so youl need a both manifolds suited to the 186 head.
And 3rd im pretty sure youll need 186 length pushrods but not 100% sure on that one. Now your set to bolt the head on.

[V3N0M]

sweet that helps heaps thanks guys ^_^

[greenfoam]

The water galleries are only different if you are putting a BLUE/BLACK head on a Red block. Red 186 head on a Read 202 is bolt on and go. The smaller the engine you get the head off the more compression you get but I think the valve size diminishes also so you could be going backwards of the valves change size. Shaving the 202 head is probably the better go. Or better still a 12 port black 202 head modified to fit on

[Sammy]

just to confirm, if you use a 202 head on a 186 block you need 202 pushrods, if you use 186 head on 202 block you need 186 pushrods.

but i tend to agree with greenfoam, go the blue/black head, you'll get more power from it in stock form, and if you get it decked then it will be higher compression anyways .... oh and it will allow you to fit VK EFI if you ever want to

[Mr Robbo - The General]

im not really up to speed on this whole idea, however i know a guy that did this, and it stuffed his engine. it went for a few drives and when he gave it a gutful it blew up. maybe too much compression, personally i wouldnt recommend toying with an engine that old. mod it a little, but i wouldnt change the head. If the engine is in good shape and working nice, your best not to touch it as it might lead to problems in the future. It would still be very interesting to see the results of this if you decide to do it. let me know . catch ya buddy.

[Sammy]

theres far too many people out there that don't have a clue about all the little things that need to be right to make an engine, they just slap parts on willy nilly and in the end they do sometimes go bang.

my advise is, if you know what your doing, great get into it, if not, talk to an engine reconditioning place .... there wouldn't be many question they couldn't answer.

[Tree cutter]

The rocker arms are different between the186 and 202 heads. 186 rockers have a ball on top which they pivot on and have a nut that you have to adjust correctly to get the correct preload on your lifters. The head will have a stud pressed in it for each rocker to fit over whereas the 202 has threaded holes for the rocker pedastals to bolt down to. The 186 pushrods are a smidge longer than 202 ones so you must use 186 pushrods with 186 head to suit the different rocker arms.

[ucwepn]

Just get yourself a high comp 202 red head. You can tell what the head is by the stamp on it, HC for high comp and LC for low comp. I wanted to fit the 186 head to my 202 block in my torana but there was an issue with the head studs being different.

Or even just chase up a yella terra head. they are high comp and have been ported for excellent flow.