droidswarm

Hey,
Finally got the weather to test my firestorm out today, and as I thought I have an engine leak between the heatsink and the engine. [sm=disappointed.gif]

I thought I had a leak so went to a shop near work to get a new gasket. They only had one aluminium gasket in stock instead of the 3 brass gaskets that come fitted, so he said to use the alu one and one brass one (cos the alu one is twice the thickness of the brass). So ive done that and its got worse, when it is running you can actually see the fuel bubbling and spitting out. [sm=angry.gif]

What gaskets should I actually use? What can I do?

I really need you help.....

Thanks Alot

A

46u

My Feedback: (3)

I have had the heads off my MANY engines numerous times and never changed the head ship (head gasket) and I have never had a problem with leakage. All so changing the thickness of the shims can create a problem if you do not know what you are doing. Changing the thickness of the head shim affects compression ratio. You most tighten the head bolts evenly or it is easy to get the head cocked where it will not seal.

droidswarm

Im not sure if I should believe what he's telling me. The manual shows 3 gaskets (HPI part No 1418), which is the aluminium one I bought so Id be surprised if it was a different thickness to the factory fitted ones, but as a noob i took the advice I was being given.

BTW the tightenend up the screws evenly and in the correct order (opposites)

Should I just go back to the old 3 gaskets?

rclynx

droidswarm

He's telling you the truth...........those gaskets you call them are also called shims and they are for compression..............making sure the 2 surfaces are flat and torque the head properly are the most important factors. (torque the head can be very tricky)[:-]

46u

My Feedback: (3)

Is the engine new? Yes I would go back to the ones they came with as long as they are not damaged. You shim the head for better performance and what fuel you run but you need to know what you are doing. You are safer to use the stock amount (thickness).

Sorry to say I have found very few hobby shops that really know what they are doing and keep in mind most employees are minimum wage. All so they are there to sell parts.

droidswarm

The engine is only a couple of months old. But I have only been changing things to try and stop the leak I already had, not change the compression ratio or anything like that.

I am still confused - The car came fitted with 3 shims (to get the right lingo), the manual says you should use 3 off #1418, but the guy in the shop says use 1 #1418 + 1 old one (as they only had 1 #1418 in stock). I have checked the HPI website and it only shows this part number as a standard part on the Savage. Could there be a problem in the manual?

Thanks for the replies

46u

My Feedback: (3)

If you change the head shims or the total thickness of the head shims you change the compression ratio! So if you only run one shim unless it is the thickness of the three combined you are changing the compression. You might not have a problem running just one but you all so take a chance on frying your engine if you do not know what to watch out four.

neilt6

He said he had 3 brass shims originally, and since the aluminum shim he bought was as thick as two brass shims, he used it and one brass shim to get back to the original height, therefore providing he's got his facts straight, he's not changing his compression.

Brass Shim
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Aluminum Shim
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3 Brass Shims
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1 Brass Shim + 1 Aluminum Shim
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droidswarm

Ive just taken it apart again, and I dont think the alu shim is twice as thick as the brass ones. Think the guy in the shop got it wrong!!

Anyway, swopped it back to the original shims and it seems alot better - Its not spitting out at all while its running , however once it stopped I picked it up to check and fuel did run out of the heatsink area. The engine now looks oily all down the back. Is this normal?

Also after running about half a tank of fuel i checked the engine temp with my new temp gun - All I got was 113F!! I took the reading down the centre of the heatshrink, is this the correct place to measure?

Ta

neilt6

Yup, aim it right at the glow plug from about 1" away, straight down. And are you sure it's not your glowplug that's leaking? Make sure the little brass ring is still on it and it's tight, seems to me if you boosted your compression with a loose glowplug it would leak pretty badly. You might even try replacing it all together, perhaps it's broken somewhere.

46u

My Feedback: (3)

So from what he said this is not correct!!!!!!!!!!!![X(] What temp gun did you get? 113F is way cold and I find this hard to believe after running a half a tank. Is the engine still leaking around the head shims? Yes defiantly check the glow plug seal

rclynx

What kind of fuel are you running? If your getting that low a temp reading, its running way to fat (rich) and this could attribute to the leaking due to lack of metal expansion. If you have quite a bit of smoke out the tail pipe you should lean your mixture down 1/8 of a turn at a time till there is just a little bit of smoke when your going by at full speed. Give that a go and see what happens M8[&o]

neilt6

113F is so cold I can't believe it's still running[X(]!!! If you run an ABC engine below 200F the sleeve won't expand and the TDC pinch will have completely worn off, ruining your performance and possibly seizing it[]! Are you sure that's not 113C??? Also, ya running it too rich could really be the cause of it leaking. Try leaning it up a bit... Or a lot...

droidswarm

OK, Im back to the original 3 shims now and I took alot of time to ensure i tightened the heatsink evenly and in the right order.

Just ran a whole tank of fuel through it (it sounded really rough), was running rich cos there was smoke all of the time but its wasnt so rich it was spitting fuel out the exhaust.

There is no fuel around the glowplug, so i dont think the leak is there.

At the end of the run I checked the temp - It was 85F (20C), the heatsink was barely warm to the touch.

Im running 20% fuel. The temp gun is a Microtemp MT002 (which the guy in the shop recommended).

I must admit im scared to run it again, as I dont want to damage it like neilt6 suggested, I didnt go anywhere near WOT running today.

Couple of pics showing how bad the leak is....


Please help.....[sm=confused_smile.gif][sm=confused.gif][sm=cry_smile.gif][sm=crying.gif][sm=frown.gif][sm=48_48.gif][sm=angry.gif]

VIPER458

could it be your exhaust leaking or loose? when i first got my rc10gt i didnt put loctite on the header screws and it threw oil like that everywhere after running a few tanks thru it. and dang if ure engine is only 86 degrees wow!!!! thats way cold. you def need to lean it out as said earlier.

ben805

tune your car back to factory setting, use a hotter plug like OS #8, lean out slowly and read the engine temp again, your temp gauge might be faulty so do the water drop test on the heatsink and see how many seconds it takes to evaporate.

as for leaking, can you do a compression test? you can also go to auto part store to get some high temperature silicon (gasket maker) and put a very thin layer on the shim, then tighten up all screws evenly. Wait for couple hours then fire her up and see what happen.

46u

My Feedback: (3)

If I am not mistaken HPI engines take standard long plugs and not the short OS plug but double check. I know My HPI 4.6 does. I would think if your head were leaking that bad you would be able to hear the compression leaking or see bubbles while it was running. Yes check the exhaust for leakage. If you are running that cold you have to be running so rich that even a small leak will look bigger then it is. Clean it all off and run it for a short time and see if you can tell where it is leaking.
Good Luck!

One other thing you might want to take your pull starter off and makes sure screws in the backing plate are tight!

droidswarm

Viper458, Checked all the screws on the engine, they are all as tight as I could make them.

Ben805, How long should the water drop take to evaporate? How do i do a compression test?

46U, I cant see any bubbles or leakage when running, it seems to run out after I have stopped.

I will try to tune it tonight and let you all know how I get on.

Thanks for the help!!

46u

My Feedback: (3)

Does this include taking the pull starter OFF and checking the backing plate screws? Over tightening screws can all so warp something. You want them good and snug but not over tightened as these things have small screws.

VIPER458

yeah not to mention they are threading into aluminum. be very careful not to strip them out. also did you check your exhaust gasket? it might have torn when/if you took your header off. i believe for the water drop test it should be there for like 2 seconds. but like you said if its barely warm to the touch then yeah something isnt right about your settings

neilt6

Ok, here's what to do. First, take your hi-speed needle out and thouroughly examine it for damage then clean it. I just spent 3 weeks trying to diagnose my engine running perpetually 330F before my LHS discovered my hi-speed needle had come off it's o-ring and was in fact not moving in or out when turned, leaving it with way too much air, but enough fuel to appear rich. Yours might be stuck really rich. After you've fixed that, reset your engine to slighty richer than the factory settings and start leaning it out 1/8 of a turn at a time while simultainiously checking your temperature until the temp gets up to around 220F - 230F after some runs, then go down to 1/16 or 1/32 of a turn at a time and perfect your tune while keeping your temperature under 280F. Also, if the water actually steams off you are running within the 230F - 240F range. If it just sits there forever you're below 220F, and if it fizzles off in under 1 & 1/2 seconds you're too hot. Judging by the pictures, your problem must be near the exhaust system since what you're seeing is caster oil that's already been through combustion. If it was a compression problem there would be fuel there too.

Hope that helps!

droidswarm

Sorted it!!

You were all right!! The needles were all set horribly fat, I have tuned it now and the temp is up where it should be, there is a fuel leak which I can now see is the exhaust gasket.

Neilt6 - One last question, how could you tell the oil was castor oil?

46U, rclynx, neilt6 and viper458 - Thanks for all your invaluable assistance, its guys like you which allow us noobs to get a foothold in this hobby. If any of you lived on the same continent as me I would buy you a pint!! [sm=teeth_smile.gif][sm=shades_smile.gif][sm=biggrin.gif][sm=cool.gif].

Cheers,

Andrew

rclynx

I'm not Neil but other than smell the only way I know of to check what oil it is (chemical test)[&:]

ferrarimk13

im pretty sure he didnt do that, lol