4forall

Point taken on the insecurity, we are all victim of course.

We get a lot of trolls and or silly question on here all the time. The way you phrased your question just came off as silly. Also its very common knowledge that 10k+ is not safe for our motors, so that is probably why everyone (myself included) started the banter.

But what does it say about you who pretended to be an ogre, sitting there looking dim and slow, then when opportunity presented itself you bashed us over the head with you knowledge?

If you would have put some of the backstory in your orininal post, you would have gotten a better reception from everyone. Just my 2 cents, since i was one of the people who acted insecure and joined in the banter.

Good luck, ive always admired the rally cars and hill climb cars for their insane limits.

spets

It may be easier/more beneficial to consider changing transmission gearing or the differential final drive than trying to make this engine go to 10,000 rpm.

The dyno plots for this engine have the car topping out at redline anyway, and it is a well breathing motor from the factory. You wouldn't gain much power from trying to spin it even faster without something like ITBs, exhaust, etc. If the only reason to go to 10k+ is because "everybody else does it", I would reconsider.

Nickleby4

Sincerely Thanks to all who replied with info on this - I see it has been edited somewhat - my bad that I was not clearer from the off. Sincerely then - I apologise for my part in it.

This then in the spirit of adding closure to some very good advice re max (sensible) rpm limits, and the pitfalls around it. Apologies for the delay - personal issues have meant that the car has stood far too long now.

As background I've got this engine in a 70's Ford Escort which (while road legal) is basically a >2L spec Rally car - the key point is >2L fits a class rule over here. This is all in the UK / europe so the model names may seem odd elsewhere. Ignoring my personal problems (2 funerals and an ex), which have meant the car has stood for a year since first build, I've been battling through some shake down issues.

On the rev limit issues, I was initially very dissapointed with the engine (read on before you swear). I chose it as a stock unit, capable of making good power, but without the radical modifications that lead to high cost and lifecyling. In original trim, this thing just about got in it's stride and hit the rev limit - every time. Really difficult to drive on instinct, and I don't watch the dashboard as much as I maybe should.

Now I've fixed some of the issues though the car is transformed (that's why I said read on). It pulls clean to 9K on my tell tale revcounter, and is backing out the power so all of your instincts grab the next gear (not true previously). I've got this coupled through the standard rally spec rear end (6 link, proper diff etc), geared to ~ 120mph max. I have to say even with my cheap road tyres it bites up and just goes. Based on sundays enthusiasm (on private land officer) this thing is awsome - thursday now and I've stopped grinning.

The bizarre bit is the 2 (3?) things I have fixed to get to this:

1. Injectors. I had a partial injector failure (bad spray pattern) probably as a result of metal in the fuel (I also had a fuel pump failure - I'm not lucky with this on a brand new Bosch 044).
2. Oil pressure. the oil pressure was dropping out with the 2nd cam switching in. I was only running ~60psi @ 8K rpm. The fix for this was a larger feed pipe from the dry sump tank and you wil not be surprised to hear that I didn't try it much until I fixed it!
3. Air pump. I'm still battling a cold start mil on issue with the European air pump circuit. The last step was to wire up the original relay (with no load on it).

Out of all of this I come to realise that the factory ECU is smarter than me. I'm guessing it didn't like the dodgy injector and shut it down early. Has anyone any experience of this?

Thanks agian to all of clever b*gg*rs

Rich B.

Murphg05

This thread made me giggle...
Good luck with the project!!!!

vtec9

There is a point to increasing RPMs above 8500, even though power drops off after that.

It's about Total area UNDER the power curve, not power at one specific point on the curve.

Here's a dyno I found to highlight this.. just a theoretical example here so don't hold me to it.



Example 1) You're going 105mph in 4th gear. ~8500 RPM in an AP1. When you upshift to 5th, your RPMs will drop to ~6850.

Example 2) You're going 111 in 4th gear. ~8900 RPM in an AP1. When you shift to 5th, your RPMs will drop to ~7200.

According to the dyno graph, torque aside, the car makes MORE power between 8500 and 8900 than it does between 6850 and 7200. The area under the graph between 7200 and 8900 is larger than between 6850 and 8500, so it makes sense to run through the higher RPMs to extract the power there than it does to run through the lower RPMs and lose power.