3,0 im Bad Ass Bug

[Torben Alstrup]

Woops! Double post.

[Torben Alstrup]

Hi there.
I hope the others don´t kill us for writing in english. This is a little more than my German covers.

We have used different through bolts for the case, along with shuffle pins on center main and all 6. Same result. We broke a Scat Billet at 8 grand, - totally demolished the engine. Then a DPR race crank cracked. Then we reduced stroke to 84 mm. This one also cracked. Now we have reduced stroke to 80 mm. Hopefully it will hold up this time. Rod length was 6". We have gone down to 5,7" with the 80 mm stroke.

I will not claim that we are using the correct bolts, but I do not know what else than ARP to use. - Maybe machine the bolt holes to thicker bolts perhaps.

T.

[Mr.Boost/JBC]

What was your flywheel size and weight? I personally do not like shuffle pins and believe they do nothing to prevent case movement. The reason in my opinion is because there is too much tolerance between the pin and the the hole in the other case half. It's hard to say that is a cause for the crank breaking because when a crank breaks or even wobbles, the case is trash anyway. On the other hand, 8000+ rpm on that stroke is pushing it. Remmele's 3L, 3.1l and 3.2L redline at 7500. They could and would rev higher but they don't make power above 7000, so it doesn't make sense to rev higher.He also uses very light pistons with a very low compression height. The pistons reduce rotating mass and kinetic energy quite a lot.Reducing pressure within the case helps on everything involving reliability. That is often neglected.

[Torben Alstrup]

200 mm. 5,7 kg.Stage 3 pressure plate.
These pins work I think, as it is a BIATCH to disassemble. There are a good deal of pro´s and con´s in the matter with the shuffle pins. Especially on these longer strokes I think it is a good thing. The more steady you can keep the crank and housing the higher chance that it will stay together. We also do it on autocross engines, and they seem to "stay toigether", butr they are also only 78 mm stroke and 100 mm bore and pull 240 ish hp.
We are in no mans land, as very few have done similar before. I have been talking to Russel Fellows about it. He pulls over 600 hp out of a 2,5 l. type 4. But he only has 76 mm stroke and VW type 1 rod journals. So he has much more journal overlap, and he also "only" revs to about 7400 rpm.

T

[Mr.Boost/JBC]

The more steady you can keep the crank and housing the higher chance that it will stay together.

That´s the whole idea,which is exactly why I do not like them. As you said, there are many different opinions about them. My thoughts on installing shuffle pins etc. are they weaken the bearing saddles. They do the same thing as massive through bolts, but not near as good because you are not applying torque to them to add stability and reduce movement. Also, you are installing a steel dowel into an aluminum block. For that to work properly,the other case half must have a steel bushing for the steel dowel to go in to, otherwise it will wear out due to vibration and stress and will be useless.That is exactly what I have seen 99% of the time,a steel dowel that inserts into the aluminum case.That can not work as advertised. Additionally, if not installed correctly the pins themselves move around in their hole and wear the bearing saddle out and the case moves and most people who install them rely on the stock case hardware, which is not good enough for any high revving or long stroke engine. It is a matter of what you prefer, but for me it is a placebo solution. The case is probably the most neglected part of the whole engine, but in reality it is very crucial that all tolerances and machine work is spot on ,because it is what holds the engine together. If not, the engine will fuck up in a hurry, especially with high displacement and high horsepower.The forum is full of fucked up engine threads, because the attention to detail and proper material is simply neglected.

Is Russ Fellows still running Porsche heads? Will you be in Spa this year?

-Mark

[Torben Alstrup]

Yes he is still running Porsche heads.
WRT Spa, I do not know yet. My work contract only covers 3 months at a time, so I do not know "where I will be" come summer.

T
PS. We better stroll back to german again

[crazy-habanero]

wat neues hier?

[orlando-magic]

Warte auf die lieferung aus den usa,
Schiff is unterrwegs.
Dann gehts endlich los