Wisconsin Nitro

I bought this stuff cuz there i didint know what to use for sealing the engine

http://www.permatex.com/products/Aut...er_Sealant.htm

is that going to work or do I have to return it and get something else?

drivefastgto

That is NOT what you want to use...it probably won't handle the heat or the fuel.

I use Permatex "Ultra Black" RTV silicone, the same stuff I have used for years on 1:1 cars...it's the best of its kind. Others also use the Ultra Copper, works the same but is kinda ugly IMO, lol. Try either and you'll see how well it sticks.

If you REALLY want the best stuff, try to find ThreeBond gasket sealer...Last I checked, it was over $20/tube. The Ultra Black has given me zero problems though...I tried regular black RTV at first because that was all I had at the time, and I will never do that again.

black mamba

Permatex Ultra Copper is the stuff to use for sealing a nitro engine.

Wisconsin Nitro

yeah I just went out and got the ultra copper stuff

thanks though

any instructions on how I should apply the stuff?

SportsFans

I use this [link=http://www.racers-edge.com/store/customer/product.php?productid=24948&cat=0&page=]STUFF[/link].

black mamba

Just apply it however. Some people smear it on with their finger, some use a q-tip, toothpick, etc, etc.

Wisconsin Nitro

i used that tube that came with it and didin't put that much on

when it is dry can it be removed like the o rings that are on there?

black mamba

Yep, it just peels right off.

MTboy

This may be a stupid question but why and when do you need to seal it.. Should I have done this to mine when I bought it? Should I pull apart and do? Sorry but not sure about this...

Wisconsin Nitro

I just did it because today while running mine I pulled it in and shut it off to refuel I started it back up and the idle was way off so it was just going so I'm thinking I have a leak some were and that this should fix it

Wisconsin Nitro

how long should I leave it for? says it dries in an hour but takes 24 hours to cure?

and should I have done the cooling head as well?

BudBud

Here is a post I did on the Picco P3 sealing, maybe it will help somebody here. I vote for the copper as well, great stuff, even if it is red. BB

Here is the most unusual Picco issue. They used a plastic carb body for insulation and aluminum end bells. On some of the carbs, the plastic and the aluminum expand at different rates, probably all of them. I used red RTV to seal the first couple, then tried tire (CA) glue. If you Picco starts going wacky as it warms up, then in a few minutes it cools off to normal again, the jets setting is not the problem. This fix costs next to nothing and takes twenty minutes if that. I apply the glue in three or four coats. Just be careful so it does not run down inside the carb. I always remove the slide just to be safe. BB





I am not sure I ever had one leak here, but I always take the engines apart to inspect for metal machine shavings inside. Why not take a few seconds to apply a thin coat of sealer on the back of the block to eliminate that problem while we are in there?



I was going to make a video and decided to just take photos. Why after run oil? When I take the head off and clean everything up, I like to lube the piston during assembly and then put a drop on the crank pin before installing the rod, I put another drop in after installing the rod. That is all the lube it is going to get until fuel gets there. No sense starting dry. The alcohol is to clean all the surfaces.



It also takes next to no time to apply a thin coat on the carb base where it seals to the block.



When you get done, it looks like this, this one is an Orion 26, but it is Picco in every way. BB







This particular engine is a bump start Orion 26, everything is identical to the Picco. It was made by Picco.

MTboy

Thanks for that write up.. I know that really helped me..

BudBud

If a few seconds posting saves somebody a ton of tuning issues, it was time very well spent on my part! BB

drivefastgto

Good write-up BudBud! I sealed my HPI carb the same way (CA glue).

So, am I the only one who knows Ultra Copper and Ultra Black are virtually the same? The copper is rated for slightly higher temps, but both kinds are made to work WAY above the temps these motors will ever see...in fact, copper RTV is actually intended for automotive exhaust systems, which can exceed 600 degrees. I'll never say not to use the Ultra Copper, but the fact is the Ultra Black works every bit as well. In fact, there's even Ultra Gray RTV, again it works the same, just another color.

EDIT: I took a look at Permatex's site...I see recently they've updated their listings to try and differentiate between the different ones...
-Ultra Copper-highest heat resistance (700 degrees vs. 500 degrees for the others)
-Ultra Black-maximum oil resistance
-Ultra Blue-multi-purpose (huh?)
-Ultra Grey-"rigid high-torque" RTV, maximum vibration resistance (another huh?)

What I found funny is that the applications for each one were pretty much the same for all of them...I sold all of these for years, and most experienced techs simply color-matched the RTV to the motor they were working on...Orange for Chevy V-8, grey for aluminum-finish motors, blue for the old Fords, black for oil pans and diffs, and so on...

I looked around a bit more and I found what I may try next...a specific 2-stoke sealant, MotoSeal 1... http://www.permatex.com/products/Aut...sket_maker.htm
Among other things, it's fuel-resistant and fully seals in 20 minutes...sounds like it's worth a try!

black mamba

I love Ultra Copper. Once I seal a nitro engine with it, it stays sealed. Some of the others on the market cannot do that, in fact, I know Hi Temp Red cannot keep a nitro engine sealed. I have never tried Ultra Black on a RC engine, so I can't comment on its sealing ability. [8D]

go-to

My Feedback: (2)

100% agreed. Ultra Black is some amazing stuff for what you pay.

Wisconsin Nitro

anyone?

still haven't had a chance to run it yet so I still can atm...

BudBud

I have never sealed the head with RTV. It should have some sort of copper, brass or aluminum shim or gasket in it. Check the bolts though to be sure they are tight, loose head bolts can drive you crazy. When tightening the head, tighten all the screws in increments instead of running one in tight, then going to the next one. If you look at the top of the head and it has four bolts, pick one and turn it to the 12 o'clock position, turn it in a couple of turns, then go to the six o'clock bolt, then 9 and finally 3. The idea is to pull the head squarely into the block. BB

black mamba

No need to seal the head. The only areas sealed are the backplate and carb base.

BudBud

Normally true, but there are some places that may need your attention, the needles, the base and any joints of the main needle tube, the slide boot, the end bells on the carb, the pinch bolts, and never overlook bearings. Three times now I have purchased a new engine with a leaky front bearing. It was not mine, but a friend got a 4.6 with a fault line in the block casting, it would heat up and suck air. BB

black mamba

Well, I mentioned the most commonly RTV'd problem areas one will always encounter. As you mentioned, other areas may require attention.

Wisconsin Nitro

I ran it today and man it runs greater, possibly better then before I had it sealed i might be inclined to say

black mamba

That's always the case because a engine with a air leak or leaks will not run right no matter how you tune it. People have wasted hours of their lives chasing a tune when a air leak was the root cause the whole time.

smeyers2

Thanks Guys.. I know this is an old post... but the info is still invaluable. I am going to seal my new LRP and 4.6 tomorrow.