fuel leaking out head

[fishaddict]

After doing a little bashing in my alley this evening I brought the car in and pulled the cover off to wipe it down and noticed there is fuel spattered all around the back. So I fired it back up to see where its coming from, and its coming from between the head and the block. So I pulled off the head and there is no gasket or seal or anything, just metal on metal. Is this the way its supposed to be? Can I put a ring of that high temp sealant between them? Keep in mind this is my 1st nitro so I'm still learning. But it just doesn't seem to make sense that there's no seal. Not only are you loosing fuel but your loosing compression.

 

[Mn Monster]

there should be a copper shim between the head and block. i would not use a sealant. what rig are you running? and what motor?



this is what they look like, if your running a Traxxas rig

http://www.ebay.com/itm/Traxxas-522...ccessories&hash=item5ae8550323#ht_2058wt_1111

 

[fishaddict]

there should be a copper shim between the head and block. i would not use a sealant. what rig are you running? and what motor?



this is what they look like, if your running a Traxxas rig

http://www.ebay.com/itm/Traxxas-522...ccessories&hash=item5ae8550323#ht_2058wt_1111

Nope there is no gasket that looks like that, just metal on metal. It is a vertex .26 engine, unfortunately I haven't found a whole lot of info on them.

 

[Mn Monster]

wish i could help more, don't know anything about the vertex ! is there a copper ring around your glow plug?

 

[fishaddict]

wish i could help more, don't know anything about the vertex ! is there a copper ring around your glow plug?

If you mean the small washer that goes around the bottom of the glow plug then yes.

 

[Mn Monster]

i was trying to find a part list for vertex .26 but so far have had no luck. i did find this for the vertex .21 and it shows a head shim

http://www.himotoracing.com/product/engine/engine_004/details.php

 

[Snook Man]

Look closely at the head, sometimes the gasket/shim is silver and will stick on the head and blend in making it look like there is no gasket.
If the head bolts were tight and it was leaking, you will most likely need a new gasket/shim even if it was there to start with.

 

[WinnersCircle]

After doing a little bashing in my alley this evening I brought the car in and pulled the cover off to wipe it down and noticed there is fuel spattered all around the back. So I fired it back up to see where its coming from, and its coming from between the head and the block. So I pulled off the head and there is no gasket or seal or anything, just metal on metal. Is this the way its supposed to be? Can I put a ring of that high temp sealant between them? Keep in mind this is my 1st nitro so I'm still learning. But it just doesn't seem to make sense that there's no seal. Not only are you loosing fuel but your loosing compression.

There is no seal between the combustion head and the block. There are some shims that may be aluminum or brass colored. These need to be there because they control your compression ratio and they are changed based on the percentage of nitro you are using. Do not use any sealer!

Look at where the exhaust leaves the engine to make sure that the rubber gasket that fits between the engine and the exhaust pipe is OK. When this is damaged the engine will frequently have fluid on the back of the engine.

Lee

 

[fishaddict]

There is no seal between the combustion head and the block. There are some shims that may be aluminum or brass colored. These need to be there because they control your compression ratio and they are changed based on the percentage of nitro you are using. Do not use any sealer!

Look at where the exhaust leaves the engine to make sure that the rubber gasket that fits between the engine and the exhaust pipe is OK. When this is damaged the engine will frequently have fluid on the back of the engine.

Lee

Its deffinetly leaking between the head and the block. I can see the fuel spitting and bubbling.

 

[olds97_lss]

That missing shim is what makes the seal. It's softer metal that molds to any imperfections on the head or sleeve when you tighten down the head bolts.

Odd that there isn't one. Your 100% sure it's not stuck on the head?

 

[batmanninja]

There is no seal between the combustion head and the block. There are some shims that may be aluminum or brass colored. These need to be there because they control your compression ratio and they are changed based on the percentage of nitro you are using. Do not use any sealer!

Look at where the exhaust leaves the engine to make sure that the rubber gasket that fits between the engine and the exhaust pipe is OK. When this is damaged the engine will frequently have fluid on the back of the engine.

Lee

I am having this same issue. How many shims should there b if i am running 25% on a hpi nitro star 3.0??

 

[batmanninja]

Fixed this issue. I thought i didnt have any on there either. But they were there. I had 2 on there. Pulled them out and hit them with a torch till they were glowing orange, soften them up a bit. Put them back on and tighten the hell outa the heat sink. No more leaks.

 

[amack4]

I am having the same problem but with the vertex .18 motor. i have just finished sealing it for air leaks and now there is a leak between the head and the block and not much compression and i can see the fuel coming out. The problem wasn't there before i had it apart. What is it that you do with heating the rings?

 

[batmanninja]

Heat them up with a torch till they r nice n red hot. B carefull not to melt them tho. Prolly shood hold them woth some pliers. This will soften them up. Let them cool by themself dont use water that will hake them hard. Then u can install them back on to ur engine and they will seal up properly.

 

[amack4]

Thanks. my problem ended up being some loctite that gotten in between one of the shims and the top of the sleeve and stopped it sealing. I had to scrape it off and that seemed to fix my problem but I think that I should try heating the shims as well incase they were a bit hard as well.