Forum Messages

Forum Home Page

Date Name Message
02/08/2004 07:39:17   paul   Hi there.
Im gonna fit a tacho to my 96, and was wondering does anyone know what a reasonable red line is for the 1500 v4 for everyday (fast) driving (i dont want to rebuild it every 10000 miles!!), i havnt got it to sound like a bag of nails yet so im not sure. Do you rally boys out there get your engines balanced? does it help much since the v4 has terrible natural balance anyway (well done ford, a 60 degree v4!), how much would this raise the redline by for rally driving??
Any advice much appreciated thanks.  
02/08/2004 07:53:09   Richard   You are probably only using 4500-5000rpm on a std engine depending on carburation flat out. I run the rally car with long throw crank to 6700rpm (but I try to change gear at 6000-6500), short throw std crank rally engine can rev higher than this.
For a road car you are better using lowers revs and using the torque of the V4.  
02/08/2004 10:15:31   Senor Burt   They will rev up to 5500 before the valves start bouncing. The limiting factor is the valve springs. Harder springs will give you a higher redline. If the engine/carb/exhaust are standard though there is little to be gained.  
02/08/2004 12:16:53   Alistair   Depends on the age of the engine - early ones (silver & red) had softer valve springs and would only rev to just over 5000 before you hit valve bounce, later ones (blue and black) will make 5500-6000 but by then you're so far past peak power (at 4800!) - it's not worth wringing its nuts that far.

Put it this way - with standard gearing and 155 tyres, 6000 equates to about 42mph in 2nd and about 68 in 3rd (give or take) so I doubt you're getting any further than that in either gear!

If you sort the carb & exhaust and choose to go for harder springs to increase the top end, your next problem is the fibre balance shaft gear which is rated for only about 6300, though as Rich can testify they will cope with more revs for a short while ;-)

The solution is a steel gear.  
02/08/2004 12:24:07   Richard   Valve bounce limits the engine revs as Burt says. I have not driven a std car with rev counter or bothered to work it out so 5500 sounds right for the valves to bounce. My rev counter is in my ears and head.  
03/08/2004 13:31:14   steve h   Ive always been under the impression that the max published revs for a standard engine are 5400. The gear change indicators on old style speedos would tend to confirm this against my tacho. Those sorts of revs on a standard carb/exhaust set up are very undignified, pretty pointless powerwise and sounds silly. However change the set up and the engine feels like it just wants to go on and on, especially with a twin pipe.  

Post Reply