LOL

Can any one give me the measurement for a P5 crank pin new please. I want to get mine measured and see if mine is worn...

4.98-4.99 new
Recommend being leary of re-rod anything less than 4.92mm

Thanks Monty ill get the machinest at work to run his magic over it

you gonna try the "insert" crankpin method?

i am real skeptical of that i have seen two cranks that have had that done , it worked but something just says "red flag" to me on that


rick brake used to but might still turn down the crank pin round again and insert new rod bushingto match with the standard factory clearances , that worked pretty well also

So, I disassembled the 21-4C that was giving me a hard time the other day, and there were a couple of minor suprizes.
One thing was there was a massive ammount of carbon buildup, in the ports there was what I'd describe as a .5 mil thick layer of crud with some actual lumps, on the rod there was a layer of carbon, in the combustion chamber/button head there was a thick layer of crud again around the circle around where the plug sits, and on top of the piston there was an unusually thick layer of crud which seemed to be sort of sandy/uneven in texture.

The sleeve was stuck on the button head, and I mean really stuck, I couldn't get it off it. Is this normal?

Then for the sake of it I measured the lower hole on the rod, and it was 4.99mm from side to side, and 5.05mm from top to bottom, does this say anything about use?

Anyhow, I figure this engine seems to have seen some use? am I right?

I'm looking for my first Nova engine. I've been looking at the 4btt for my mugen mbx6r. Is this a good one bone stock or should I get a modded one. Any of you guys have experience both stock and mod. Is it worth it

Thanks

Steven

Monty was just going to get him to check for roundness and size if its under or out of round ill throw a new crank in

depends what you are after.... stock they are quite nice, they have good bottom/midrange and a reasonable top end...... Some people love them the way they are, others find them to be a little too mild....I cant speak for others but my modified version is a pretty substantial bump in power and RPM over stock....bottom end we gain a little, midrange we gain a fair bit and the top end of the modified absolutely sings compared to stock.......The modified version carries all the same characteristics as stock, except its a whole pile faster......... Some love them the way they are, others will like the modified version better..... just depends on how much juice you want .

Thanks Maximo. Can I pm you on what I want as I don't want this to become a war on motors.

Of course !

My first thought: You are running a too cold plug or old Novarossi plugs (+1 year old)? Try a brand new C5 or C6 plug or even a O'Donnell 77T plug.

Dont know about the rod and crankshaft pin

so running in some nova engines on a hudy bench anyone else got suggestions on the best methods and or time to run on the bench etc etc
cheers

I was running a brand new P3, but the engine was a 2nd hand unit so don't know what people have been running before..

I'm just trying to evaluate whether this engine "has had it" or not.

That should be hot enough! . Will follow your post and learn from it

Temps between 100 and 110º C. With full tank it shall be 100ºC. When the tank is nearly empty the temp will climp to a little under 110ºC.
Ambient temp between 15 and 25ºC.
3 tank at idle speed.
The next 4 tanks with a little more throttle after each tank so you start the 7th tank at 50% speed. The last 8th tank with various RPM and no full speed runs for more than a second or so at a time.
Maybe an extra shim under the head.

This is how I do it.