2.2 race motor rebuild

[Walko]

Mark is your cage all chrome molly??

Would that be the reason why it only weighed 46kg

Michael

[bumble]

Michael,

Yes, the whole cage is Chrome Molly built by PRT. Many $$$ and several CAD designs before we got an engineer's sign-off that would pass CAMS approval. I doubt there is a better cage in a 914/6 anywhere in the world...

Ryan had his built by Bonds I think - you might want to ask him how much it weighs....

Andrew Kirkbride (AMK) had his built by PRT (also Chrome Molly I think?). You could ask him for details...

Cheers,

Mark

[snowman]

Your cylinder heads have ports so large that they will support much more power than you can ever realize. So just make sure your ports are matched and all the flashing is gone. The Power is in the following areas:
1. Compression- do everything you can to increase the compression, as its free hp.
2. Cam- even the stock T cam can make 160Hp if properly timed, other cams can make up to 200HP at fairly high RPM. BUT if you don't have piston squirters and extra oil coolers, don't do it.
3. balancing and shot peening are free, do it.
4. have everything bolted togather for a final flow test, should flow almost the same as just bare heads if everything is good.
5. Dyno- jet it on a dyno, do it right.

Real power is only obtained using a dyno, no other, reasonable, way.

[Walko]

Snowman,

Thanks for your input.

I see that one of the areas which I should be able to gain some HP is by fine tuning the advance curve.(trial and error) as well as the MFI

Michael

[cnavarro]

Walko, the weight savings of the Nickies are just a bonus. Especially in the case of the 2.2, the Nickies will reduce your head temperatures drastically, 100-150F, and that's good for 10-15% more horsepower, torque, and fuel economy, over the stock cylinders. Oil temps should drop by 20F or so. You might even be able to afford reducing your fan speed and gain a few more horses that way too, with the extra cooling of course :-)

Charles Navarro
LN Engineering
http://www.LNengineering.com
Aircooled Precision Performance

[BigD9146gt]

Mark, could you post some pics of your roll bar?

[snowman]

Walko,

Don't expect anything out the advance curve for a race car. Why? because most all advance curves are maxed out by about 3000 RPM and most race cars never run that low.

The max advance is the only thing you have to work with. About 32 degrees up to 36 degrees or so.

[Walko]

Charles,

Thanks for your input.

Michael

[Walko]

Snowman,

You must remember that this car will be used for Tarmac Rallies as well as Circuit racing and there are quite some first and second gear corners. So it is possible that the revs may go under 3000 in first and second gear corners.

Michael

[Grady Clay]

Michael,

Your issue with an engine that can stay together for a long time has to do with RPM. An engine you shift at 7300 (or even 7500) will last a long time if built properly. If you turn it 8000 – 8500 all the time then I like a 25 hour rebuild schedule. The maintenance overhauls are SO much less expensive than some disastrous malfunction.


Mark, I don’t consider boat tailing the case, knife edging the crank, mooning the cylinder spigots, and more to not be worthwhile for a high rev engine – 7000 RPM. This significantly reduces pumping losses inside the crankcase.

Michael’s reasons for using Nikasil cylinders are just fine but it also includes better ring sealing and performance. Nickes = horsepower.

Anything you can legally do to raise the compression ratio makes more power. You just need suitable high octane fuel and keep the cylinders and heads cool.

One of the things I noticed in the rules is you ability to use a higher ratio fan drive. That has a net HP gain and helps the engine longevity by keeping the cylinders and heads cool.

Do the rules allow the “Rubbermaid Solution”? Search on this Forum.

If you can legally use twin plugs – go for it!

With camgrinder’s hotter cams, perhaps you can use even higher CR – say 11.5:1?


I’ll go re-read the rules posted. There is usually much to be gained.

Best,
Grady

[Walko]

Grady,

Thanks for your input.

To stay in SS you can't run dual plug.

When you say maintenance overhauls every 25 hours what would you put into the motor.

My logic would be to ensure that oil and filters were done every 10 hours. surely turning a higher RPM would not dramactically decrease the life span of the bearings and rings. I am no expert so if some one can advise why the shorter life tim eon higher revving motors I would appreciate it.

Michael

[bumble]

Grady,

(Quote) I don’t consider boat tailing the case, knife edging the crank, mooning the cylinder spigots, and more to not be worthwhile for a high rev engine – 7000 RPM. This significantly reduces pumping losses inside the crankcase.

I agree - for a race engine that will see sustained high revs it is logical, but others seem to be rather sceptical. Done properly, the worst that can happen is to lighten your wallet .

The issue that Michael faces (and others of us for that matter) is optimizing his setup for multiple use (Tarmac Rallys and club sprints) within a sensible budget which includes not only the engine, but transmission ratios, suspension set up and so on. A car optimised for the track can be a complete dog in a tarmac rally. As we all know, making the last 10 or 20 HP can be a very expensive excersize, money which may be better spent elswhere. In any event, the Standard Specification (SS) category deliberately restricts modifications by several catch-all clauses. I would be amazed if anyone here could conjour up much more than 200HP from a 2.2 given these regs. I am however allways prepared to be amazed

Don,

Being a professional technologist but a personal Luddite, I am sans the digital camera thingy. However, here is a picure of my cage prior to being installed in the car. If this doesn't work, you can find it at www.prtechnology.com.au, click on Performance Products, scroll down to Roll Cages and click on the picture. Mine is the first cage displayed in the upper left of this page. The cage forward of the main hoop is removeable. Being 6'2", we needed to make as much room as possible, so removed the section of bulhead between the seats, welded in the main hoop and then welded the section of bulhead back in around the cage cross-bar. I now have good leg room. Not shown are the rear facing bars which are welded back to the chassis below the shock mounts, necessary to pass our CAMS engineersing requirements but has the added benefit of stiffening the whole chassis by a huge amount.



Cheers,

Mark Lamberton

[snowman]

Originally posted by Walko
Grady,

Thanks for your input.
....surely turning a higher RPM would not dramactically decrease the life span of the bearings and rings.......

Michael

That extra 1500 RPM is the most expensive thing you can do to an engine. Wear goes up exponentially along with cost. An engine that can live for many years at 7000 RPM might only last minutes at 8000 RPM . With lots and lots of extra bucks the minutes can be made into hours. For competative racing you must be on the edge to win, if you are not you will not win. What that means is the person who pushes everything to the point where it breaks one second after the race ends is the one who wins. Add to that skill and you have only the best driving things, that are just about to break, winning. Then there is the rest of us.