Twisted_Metal

I just have a quick question. I have a new JP .21 FX-03. I broke it in to about 12 tanks., but the problem I'm having is the pinch at TDC is so tight the engine won't turn over with the plug removed. I have to heat the engine to about 200F with my heatgun. I'm pretty sure this is normal, but geez how am I supposed to heat up the engine when I don't have access to a heat source eg. (parking lot, race track etc.)

wingracer

iTrader: (24)

Just keep going. It will loosen up eventually. Just don't lean it out or go full bore until it does.

If no power is available, use a blow torch. Just go easy with it.

Twisted_Metal

I don't think my thumbs or my body can take it. I feel like this engine is tormenting me every time it gets stuck at TDC.
I can recall my AXE Rossi Cobra .21 being almost this stubborn, and it has about 4 gallons through it and still going. I know there's a reason for this madness, but sheesh! ...

Tank number 13 tomorrow ...

Geezatec

I've alway a tight pinch is always a good thing. Last longer in life of engine. When starting and stuck at TDC, Make note that when storing the engine, Bring piston down to BDC. You really don't have to use a heat gun. Just when cold, loosen the glow plug one turn. Install igniter, and crank till it starts. Leaving the igniter on 2 second, them remove igniter and tightening the glow plug. Engine will start with a loose GP. Pinch will disapate in time, you won't have to do this procedure. Let the engine break in on its own. Seized piston!! I remove the GP. Useing a plastic dowl, tap down the piston.Why You Ask!!! When the engine stops, Crankshaft and piston will always stop at BTDC. Easier to tap it down then turning the engine over TDC , may cause a bent conrod.

Break it in the natural way then imitating heat exspansion.

That My .02 on the subject.

Twisted_Metal

I've tried all explained above. The glow plug was removed to no luck the pinch just locks the piston in place at TDC and if I try to turn it over cold all it does is puts scratches and scuffs on the piston and locks it even tighter. I need a portable heat source.

Geezatec

Engine uses a Chromoly Sleeve W/ aluminum piston. One revolution of crank is 360 degree circle. Pinch start at approximatly at 270 degrees. At pinch compression starts. Compression start at 270degrees, so it starts BTDC, cuz the sleeve is tapered till pinch. It takes time for the sleeve to get into operating temp.

When cold it may be tight. If no heat gun. Here another procedure you can use, or try. Remove GP, Turn crank to BDC. Use two drops on ARO( after run oil) in the cylinder. Crank useing pull start. Use the complete cord of pull start. After a few atempts is should be able to complete a few rotation. Hold chassis firmly on ground. Install GP one turn loose, so some compression is lost. Apply igniter, and try to start engine. When it starts remove igniter, and thighten GP. resume break in.

360 degrees in one rotation, 90 degrees of compression. Sleeve made up of Chromoly Not much scratching caused. When you do a heat cycle. Pinch may still sieze, appoximately 30 minutes, but not as bad. Just loosen the GP one turn And start engine, remember to tighten GP. When it runs out of fuel, it'll be easy to refuel and restart, cuz it is hot(operating temp)

After running a gallon of fuel it should dissapate. You should be able to start normally.

Good Luck!!! I've used this procedure with tight pinch for 26 year with no problems.

Scott Fisher

iTrader: (28)

This is a racing engine..... No pullstart on racing engines

Geezatec

Even better if useing a box. Procedures work better on starter box. Especially with ARO & and loosening GP one turn. W/O GP two drops of ARO, on starter box, crank over 5 seconds, Install GP one turn loose, install igniter, when it starts remove ingniter, then tighten GP.

Like I've said, used thiis procedure for 25 years with no problem.

Good Luck!!

wingracer

iTrader: (24)

Then you have no experience with Nova based motors over the last couple years. They are not just tight, the things will completely LOCK UP at tdc when cold and new. They really need to be pre-heated for the first half gallon or so.

Your advice is perfectly fine for 99% of the motors made over the last 25 years. These new super tight monsters are a completely different animal.

helivaguy

iTrader: (42)

+1
be patient with the process and your engine will serve you well.

Geezatec

My experience come on Nova, Nova-Mega, Mega, NovaRossi, And RB product. And Mostly Ron Paris who been gone a while. RIP. For piston to be seized at TDC, You don't bring it down to BDC when storing. Like the guy said, what do I do when in a parking lot. Sure he can purchase a heat gun, then he need a Generater to run the heat gun. Or he can move to Vegas and leave the car in the sun is 100+!!!! Just don't put my procedure down till you try it. I garauntee you'll like the procedure.

I said b4. The engine stops, not at TDC, it stops at the beginning of the pinch, time after 270degrees of rotation. And its better for anyone to tap down the piston in opposite direction to avoid bending the conrod.

Like Helivaguy be patient with it. It'll loosen up after a gallon.

Twisted_Metal

The real problem is me just being impatient I suppose you are all right ... Anyhow, I got to run the car on the ground for 2 tanks but then the motor got stuck again. I purchased one of those mini butane flame-less heat guns the other day to take to the lot but it seems it wasn't that efficient in producing enough heat after the second tank even with the heat sink wrapped in foil.

*1speedy

iTrader: (12)

This is imo the best product yet to heat an engine. You can even leave it on while waiting for you qualifying heat.

Not only will this help with starting but imo will prolong the engine life.

helivaguy

iTrader: (42)

does it come with a generator?
looks nice tho..

JetMD

iTrader: (1)

If the heater is DC, you could run it with a battery. Don't know what powers it though. I had a 12V battery and inverter (which is cheaper than a generator) in my trailer.

I know it's a little late but, the break-in technique you use will determine how fast you loose pinch. Usually, the manufactures method will leave you with alot of pinch. This is great to make the motor last a while (as long as you change the rod). If you want to lose the pinch and get it up to race spec. quickly, I suggest this method next time http://cefx.net/catalog/breakin.php Very good and popular method to break-in any motor.