4ag 16v headgasket with 20v head

[toymaz]

Hey all
I was wondering if anyone for sure, if a 4ag16v headgasket can be used on a 20v head.
I have received 3 incorrect h/g now ordered for a 20v, as there is only slight differences with water holes on opp sides, i can't see why they won't interchange . Im thinking it might be because of the waterflow,.
any ideas?
Thanks

[skiddz]

search and ye shall find, it has been covered, and no it wont work just get a 20v one worst come to worst talk to castle hill and im sure they will have somthing to suit.

[toymaz]

Did try to search-thankyou as i new that was a reply.
but didn't find much, some say can use a 16v
And i already have a std one, but im don't want to use it, as its not a standars NA.
thanks

[shelldrake]

Why won't a 16v one work skiddz? Have you tried it?

Toymaz - I have a brand new standard 20v head gasket if you are interested...

[toymaz]

thanks for the offer shelldrake, but i have a new standard one already, thats why i can't see the big deal between them.

[beerhead]

It depends if you're in standard FWD configuration or a block off plate in RWD. The water holes control the pressure on each side of the head, ensuring even flow. They should go from small to large as you work your way around the head away from the outlet. If you have large holes close to the outlet side the motor would be more inclinded to just allow the water to flow through the easiest path, from the block and straight out the outlet.

I've had a theory for a while now that if you're using a rear block off plate a 16V gasket will actually be a good thing. The water system is working like a 16V motor, so it should flow from the exhaust side around the back of the head and out the front housing. Using a standard 20V gasket means that the exhaust side has the small holes and the inlet side has big holes, meaning a majority of the coolant is flowing straight up to the water outlet, heat soaking the exhaust side of the head.

If someone's got a pic of a 20V gasket I'll do a mud map for the flow if you don't understand what I mean.

[toymaz]

Wow thanks , thats good info
makes some sense to me, and i am using a RWD 4a waterpump set up , with a block off plate at the rear of the head like you mentioned, so i guess it flows like a 16v.
Thanks heaps

[psychofox]

They aren't the same, I have seen so many threads asking this. Use the 20V Head gasket on a 20V head.

See my response in this thread, with pictures. http://www.toymods.net/forums/showthread.php?t=8330

[toymaz]

Thanks for your input, and link
however i have a standard 20v and a used trd 20v and they are different to the toda one, and i have a trd 16v and a cometic 16v and they are different to the toda 16v, the main difference on the trd ones is the water galleries holes on the 16v are one side and on the 20v the other, but the head has holes both sides anyway, going buy your pic of the toda 20v i can use my 16v cometic as close as.
cheers

[Sam_Q]

beerhead, interesting points but a stock 20v cooling path and a rwd convert 20v with a rear bypass backing plate still has the exhuast side coolant flow in the same direction. Only the order and direction of flow on the intake side of the head is different