quick noob at circuit racing question.

but why would you want to rev out to 10,000 rpm on a circuit?

 

Ok...

2.3RR - cool engine, but not in my budget, especially not with international freight costs.

Thanks for the blog link zEvo, I will check it out today.

10,000rpm... well it's all relative. 2.0L circuit engine may have a usable power band of 5,000 - 10,000rpm - a 2.3L might be usable from 3,000 - 8,000. Both have the same effective power band.

IMO, it really comes down to personal preference in the end. I like an engine that revs hard, and I like to do things differently. To that end, I have been researching 2.2L setups, as I believe they may offer an ideal compromise between revs and lower rpm torque, while also being a better design from a mechanical engineering perspective (rod ratio, piston speed etc).

It's all very fascinating and an educating experience though! I have a few months (at the earliest) before I need to make a decision on the engine, so plenty of time to get things right!

 

Bushur I am sure has the goods you are looking for. Ask Dave I love that he is so down to earth and willing to talk to you.

 

It's really quite simple. The greater the frequency of rpm changes on a given course, the more advantageous a larger displacement engine will be.

 

Nice man, very nice.

 

Current thinking at this stage is to build a 2.2L (94mm stroke) with increased SCR.

FYI, 2.0L (88mm stroke) at 10,000rpm has a piston speed of around 29m/s. The 2.2L (94mm) crank will achieve 9,500rpm at that same piston speed of 29m/s. While I am not saying I would rev the 2.2L to that rpm, it shows that the 2.2L has a much better piston speed when you consider that you only sacrifice 500rpm for a 200cc capacity increase.

Search is now on for a quality 2.2L crank. Any suggestions?

 

I would stay at a lower piston speed .... say 25m/s max

 

Does anybody know what the length of the rods in the Cosworth 2.2L kit is? Their marketing constantly says "ideal rod ratio" but I can't find anywhere what the actual rod length is.

 

Found the length of the Cosworth rods... 150mm... hmmm, not too impressed.

I'm currently doing the maths to find out how far the wrist pin can be moved on a piston, to allow for a longer rod. I know of one working combination for increasing the rod length on a 2.0L, and am looking at what's involved to do a similar thing to achieve close(r) to a 2.2L capacity.

There are so many possible combinations, and when you look into custom rod and piston designs, it's just infinite.

I think the only thing holding me back from a 2.2L (apart from money) will be finding a crank that I am satisfied with from a structural point of view.

Thanks to you guys for all your help so far. If you think of anything else, feel free to add it in here!

 

you will find that the good 2.2 cranks are very expensive. you could go with an eagle 94mm crank if you wanted to keep costs down. other than that the other sources that do a 2.2 with long rods are marco at www.magnusmotorsports.com and mark at www.madevelopments.com. you may also want to consider running a destroked 4g64 2.2 setup, which is more economical to build. you can run a 94mm crank, 160mm rods and custom 87mm pistons. norris designs, www.norrisdesigns.com, builds motors like these and probably can supply you will the internals as a kit. short of that you can contact moses, moses@amsperformance.co.uk or moses@gscmotorsports.co.uk, who sometime stocks such a kit.
good luck.