what should i rev too?

[wedggie]

Well, a nice chap came to see my 390 today and loved it but didn't buy the car because he thinks there's something up with the engine. It revs up to 5250rpm and hits what sounds / feels like a limiter. It gets there in no time and doesnt sound off in any way... It doesnt miss a beat, but he still thinks theres a problem.

so here's my question (obviously) what should a 390se rev too? The video might help show how its running...

http://www.youtube.com/watch?v=3_OutnRdyYQ

Help appreciated.. If its supposed to be even quicker theres no way id be able to part with her!

[superwedge]

sounds good to me ,sounds like my 350i,maybe he got too much wax in his ears

[wedggie]

superwedge said:

sounds good to me ,sounds like my 350i,maybe he got too much wax in his ears

is that about your max revs too? just looking on the books and tvr quote speeds achieved in each gar at 6000rpm...

[mrzigazaga]

Hi mate..Sounds healthy...Not sure what the 390SE are limited to but i think most are limited to around 5600-5800rpm...Ziga

[wedggie]

mrzigazaga said:

Hi mate..Sounds healthy...Not sure what the 390SE are limited to but i think most are limited to around 5600-5800rpm...Ziga

Thanks Zig, I wondered if the timing was a little off, but it seems to run too smoothly

[mrzigazaga]

The timing is always worth checking but by the sound of it the motor is fine...Does your friend know V8's?...They are not high revers like modern cars..Its all about the low down torque...Sometimes problems are created with these cars by tweaks and adjustments that are really not needed..The only way you can really see what is happening s on a Dyno so if you know a good one then its worth the money.....Ziga

[keatsie]

Stock 390 engine maximum RPM is around 6500 for short bursts only, as maximum power is around 5200 rpm. Personally anything past 6000 rpm is wasted and I wouldn't really run much past this, but that's only my personal opinion.

[matt-man]

Mine doesnt like reving past 5K..the furthest i would take it is 5200 but its always been like that and you lose all power after that.

Here is a shot of the dyno reading for my car...this was a few years back - 2008 (wow time flys!!) and i really should do another (BBWF hopefully...)



Anyhow, as you can see, i told them to stop at 5100 and you can see what was happening to the power...I have no idea what cam i am running, assuming stock.

[ElvisWedgely]

If that is his excuse for not buying the car he is a dreamer. I would have told him to go and waste someone else's time.

Tony. TCB.

[keatsie]

I strongly agree with Tony..

[PHJayV8]

ElvisWedgely said:

If that is his excuse for not buying the car he is a dreamer. I would have told him to go and waste someone else's time.

Tony. TCB.

I agree too, a ridiculous excuse not to buy a car.... :/

[PHJayV8]

ElvisWedgely said:

If that is his excuse for not buying the car he is a dreamer. I would have told him to go and waste someone else's time.

Tony. TCB.

I agree too, a ridiculous excuse not to buy a car.... :/

[marcus1875]

PHJayV8 said:

I agree too, a ridiculous excuse not to buy a car.... :/

yup, I fully agree.
marcus

[mrzigazaga]

Tell him to stick his earhole near the exhaust as you think you hear a weird noise...Then give it full beans..He might not be able to hear you for a minute but everyone can lip read the words.."fk off"...

[matt-man]

haha - nice comments chaps!!

If he's a numskull(and lets face it, there are plenty out there) and the have red online about how rover v8 engines 'Eat camshafts' then if he test drives a car that has a redline at 6K on the the tacho (which i know mine does) and it wont go near then he might be concerned...

But after hearing that vid, its obvious there is nothing wrong and the guy is a t$at!!

[keatsie]

It is possible you have a standard rover fuel map in your ecu, On the standard Range Rover fuel map does not increase the amount of fuel above 5400 rpm, but simply carries on fueling as if the engine was still at 5400 rpm, this does reduce power quite quickly.

[V8 Fettler]

Is the rev counter accurate?

[350zwelgje]

Rev counter is not accurate and reving over 5250 is no use on my standard 350i. It is possible for me to rev to 6250, would asume you to. Could be that it is useful on a 390se. Probably wedg1e can help you on this.
Seems you have a range rover ecu, which is limited and hydraulic lifters (if fitted) can keep the valves open. Both can act as a rev limiter.
Seems the buyer has missed a good opportunity....

Rob

[wooly350i]

My old 3.5 engine used to give me concerns when I could detect a top end rattle at around 3000 revs, pinking perhaps is the correct term but yes weak valve springs might explain it

[Wedg1e]

My 390SE revs past 6000 easily enough but there's little point in doing so as peak torque is about 4200 IIRC and max power about 5300.
The car does have an electronic rev limiter fitted but I disconnected it when I was trying to figure out what was causing an artificial rev limit at about 5500... it turned out to be the pickup coil in the distributor dying: wih it replaced, normal service was resumed but I never did reconnect the limiter...