New engine

[Elnef]

Well 5 weekend in a row was the end of my crank it is broken again
I can rotate flywheel so I belive it is broken just behind end bearing hmm
It was making so much rpm that my rotor explode

[Neil Davies]

That's terrible luck. I've never seen a rotor arm explode like that though!

[Erlend / bug66]

The most unlucky engine ever? I feel for you..


Could there be a common fault here? A crank balancing machine thats not quite right etc?

[Airspeed]

The most unlucky engine ever? I feel for you..


Could there be a common fault here? A crank balancing machine thats not quite right etc?

Not unlucky and probably not a balancing fault either.
Imo a 86 stroke with long rods and 104mm bore pistons at far over 7K gives (way) more crank flex then smaller strokes with smaller bores unless everthing is extreme lightweight, like Titanium rods and those kinda things.
Extreme stiff cranks are what you need AND extreme light weight rotating mass with those RPM's is the only cure to keep it in one piece imo. Everything that helps stiffness (larger mains, better steel, better surface treatments, etc) should be looked into. All those steps usually costs way more $$ then the 'off-the-shelf' parts.
But thats just my opinion and probably not a new fact to Elnef ;-)

Just saying that - imo - it surely hasn't anything to do with luck or bad balancing imo.

[Elnef]

I think I have found the end of what the parts I have bought can handle 80x105
Today I got time/energy to look at it again
Just about everything need to be replaced block crank rod piston liners etc etc
But this time I think its time to step op a bit but what to buy any info is welcome 😉
I think pauter but I know about nothing if it will last or not

[mikko k]

Welded crank is NO NO for racing!

Pauter can handle 1000+ hp. It might be enought for you? 

[Elnef]

I broke a scat billet 86mm years ago thats why I tryed a 80mm dpr its god german steel

1000hp yes thats way enought I am no turbo guy 😉

[Garrick Clark]

I believe AIRSPEED has given the correct answer with regards the crank. The fact that the crank broke at the flywheel end tell me that the motor must have been at high revs with a side step off the clutch and bang went the crank. I've seen/read about it before. This is the reason I stick with 66 mm cranks on my T4 turbo motor.

All the best for the your next motor.

[richie]

Welded crank is NO NO for racing!

Pauter can handle 1000+ hp. It might be enought for you? 

I am using a welded DPR in my 67, it makes about 300hp and I shift at 7800rpm, been in car for last 3 years or so, plenty people using them in higher hp and more rpm than me and they are living ok so they can work ok, as John has broken at least one other brand crank I think there is another issue going on here but I don't know enough about type 4 issues to comments on what that might be

cheers Richie   

[Airspeed]

but I don't know enough about type 4 issues to comments on what that might be

cheers Richie   

Don't immediately assume it then must be a type 4 'issue' mate 

I know the 1303 CSP racer with its 3 ltr type 4 engine with 86 stroke runs way over 8K rpm and over 300hp afaik and never heard him break a crank. Maybe you can contact him or Udo as they seem to work together, even though Udo hates type4's as well 

BTW, Scat does sell real forged type 4 cranks as well as their cheap billet forged cranks (they don't advertise these iirc)...there is a difference ;-)

[richie]

Don't immediately assume it then must be a type 4 'issue' mate 

    Of course it is  ;





































A type 1 would have broken a lot quicker   but seriously there is something funky going on here, am wondering if t4 crank being longer has anything to do with it, maybe flexes more, I wouldn't expect a 86mm t1 crank with t4 size mains to fail like this but maybe I am being optimistic 

[Airspeed]

Predictable 

[Elnef]

Thanks for all your input
It was when I shifted to 2nd it broke
I am i contact with udo this time and also last time it broke
Csp 1303 was with a 86mm scat billet
My scat crank was about 1500$ I dont know if it is the cheap one but dont think so

[Garrick Clark]

Does the end of the crank look like it's been twisting and then let go or is it a clean break. Wondering if it was faulty from the start. It's rare for it to break like that.

[Airspeed]

My scat crank was about 1500$ I dont know if it is the cheap one but dont think so

Sorry, but yes, it is...

[Elnef]

My scat crank was about 1500$ I dont know if it is the cheap one but dont think so

Sorry, but yes, it is...

No problem 😉 it was about 10years ago I bought it so cant renember

[Elnef]

Does the end of the crank look like it's been twisting and then let go or is it a clean break. Wondering if it was faulty from the start. It's rare for it to break like that.

At my first look it is not tvisted more like clean break

[Garrick Clark]

How's the rest of the engine.

[Elnef]

Bad.......just about everything between heds need replace
Heads need new spring and maybe valves and guides

Time for a little brake tomorrow I will go to Sweden to see gasolin street week (swedish drag week) 😃

[wph]

What is the material of your crankshaft pulley? Steel or aluminum?

I would be very concerned about using heavy pulley on the other end of the crankshft especially if it is long due to torsional vibrations.
Crankshaft, pulley and the flywheel are a system with a certain rpm's when it is "excited" and torsional vibrations total amplitude might
peak higher with a heavier pulley than a lighter one. A lot of engineering goes into designing crankshaft vibration dampers and generally
it is not recommended to install one into an engine which the part was not originally designed for. Same thing applies for removing OEM damper.
Just a food for thought, I am deffinetly not an expert on the subject.

Pekka 
   

[Elnef]

Back home from street week what a great event 5 days 5 tracks a lot of racing about 7 hours every day 🙂🙂

My pulley is a heavy steel

[Elnef]

Time for a little update
All my type4 engineparts is sold to a good friend and I have bought another engine belive it or not its a type 1 😜
Its a old jpm build 2387 he did for johan dryselius 👍

[andy198712]

Wow!

is that going on E85 or?

[Elnef]

At JPM it was dynoed on vp race fuel a friend of mine selling sunoco race fuel so I think I will try sunoco gt+

[mikko k]

Interesting engine! How fast it has gone and how much were the weight of car?

[Elnef]

Johan ran 9.85 in a 520kg car + driver
My car weight 660kg + driver so a 10sek something in my car

[mikko k]

👍

[Elnef]

Almost a year since I bought this engine but been busy with the green oval but now I got time to take the new engine appart
Everything look fine just a clean and back again

[Elnef]

Getting closer to start up 😉

[Elnef]

Time to put engine in car and make some drysump lines