differences in head gaskets (E15 vs E15ET)

neoexa · Post by **neoexa** » Mon Jul 15, 2013 6:47 am

hi guys just wanted to know if there is a difference between the E15 carb head gasket and the E15ET head gasket? reason for asking is coz i just built an engine (stroker E15) non turbo. im using a very high comp piston so far i have gone through 3 gaskets and i had my head resurfaced by the engineers. now im thinking that my comp is a bit too high. so i have 3 options i can either remove the pistons and have them machined a bit or i can have a copper gasket made to reduce the compression or remove the engine and have it rechecked by another engineering shop just for difference of opinion but before i do this i first wanna try another head gasket and thats why i want to know if the turbo gasket can take more compression than the N/A gasket. Thanks in advance

Damo · Post by **Damo** » Tue Jul 16, 2013 6:37 am

The gaskets are/should be made to the exact same dimensions. You will find however that over time (since the conception and introduction of the engine) that updates have been made to the gaskets to promote flow in certain parts of the head. ie, coolant passages have been either restricted or blocked off all together, so don't be fussed if the new gaskets you are using have only have half the coolant holes.
As for the turbo gasket being made stronger than the NA version, maybe, but I have used NA $25 head gaskets on my turbo donk for years with good results. The engine is far from standard and the gaskets don't show signs of failure due to material construction (in the short term anyway).
It all boils down to one thing, your engine is detonating and taking out the weakest link which i'd suspect would be the gasket. I would suggest staying clear of a 'better one' as the next 'link' will be the pistons.
How much compression is the engine running on what fuel?

Damo

neoexa · Post by **neoexa** » Wed Jul 17, 2013 3:01 am

thanks for the info and advice buddy.... i dont know what CR i have but i dont have detonation problems i only have headgaskets blowing. my most recent episode of a blown gasket i had my oil was almost the same colour of milk. and oh here in South Africa we use a 95 lead replacement fuel. im sure u probably have it there in your country aswell. oh and 1 thing i also know is that the guy that i bought the bottom end from has fitted a brand new oil pump to it but he also increased the oil pressure by placing a 10 nut inside the pump to act as a shim to increase the pump pressure.

Damo · Post by **Damo** » Wed Jul 17, 2013 10:56 pm

Is this happening straight away, of after a 1000ks or so? You are getting coolant into your oil, and it may not be due to blowing a head gasket! I'd be doing a pressure test of the cooling system/head to find where your coolant leak is. It sounds as though there is a crack from one of the water galleries into an oil drain area of the head.
It would be a very rare occurrence to 'blow' a head gasket to cause a leak from a water gallery to an oil drain.
Also, detonation (if the block and head surface are true) is the only way you will blow a head gasket! Turbo or not.
I had shimmed up an oil pump in the past to increase oil pressure at idle, how much pressure is it pushing?
LRP doesn't exist in Australia anymore, but was terrible shit here, and I would avoid it at all costs.

Damo

neoexa · Post by **neoexa** » Thu Jul 18, 2013 3:44 am

after like 2 3 races my oil will start to change colour then 2 3 rides after that then my oil would be very white. ill also have it pressure tested to check for any leaks. also bear in mind i got a very big bore so might it not be possible that due to my water channels being very close to my bore the compression is now pusing into my water ways and is now forcing its way ino the oil channels coz i checked my gasket today and from what i can see the gasket blew between a water way and a oil way.

Damo · Post by **Damo** » Fri Jul 19, 2013 12:27 pm

What I would suggest would be to start a members ride page, it makes it far simpler to keep track of questions which relate to each other, plus it give more of an insight into the whole of the package and how the answers relate to everything you have done, and plan on doing.
I spotted the other post you made regarding oversize pistons, so I will answer that here rather than keeping track of multiple posts.

In order, what you should do is:

Determine exactly how much oil pressure your pump is pushing, as this may be causing all your dramas. At least you can rule it out if the numbers are ok.

Do a cooling system pressure test to find if you have a cracked head.

Have the oil analysed to find out whether you are getting water in your oil, or if it is something else.

As for the cylinders being bored enough to allow combustion pressure through, that isn't going to happen period. There isn't enough material between the outside cylinders to allow the block to be bored enough to get close to the water jackets.

For the oversize piston question, you won't be able to tell the difference between stock to 40thou over. To be honest, I would stick with the smallest oversize you can get away with if you need to oversize at all. The more meat you keep in the block walls, the better the bottom end will be.

A couple of pics of the gasket would be great.

Damo

neoexa · Post by **neoexa** » Sat Jul 20, 2013 9:08 am

thanks alot damo...... your advice just saved me alot of money. ill try to upload some pics as soon as i can and ill also highlight the blown section on the gasket. thanks buddy....

Damo · Post by **Damo** » Sat Jul 20, 2013 9:27 pm

No worries. Just remember no matter what the advice, always take it with a grain of salt. There are a million different guys who are happy to spend your money for you!

Damo

neoexa · Post by **neoexa** » Mon Jul 22, 2013 5:01 am

true that....