Budget Rally engine

[Kman1600]

Hi,

I’ve had a look through the various posts in this section and despite all the excellent info. contained within I’m still left with some questions. :shock:

I’ve introduced myself and given a short overview of my intentions within the Welcome section but to summarise I’m trying to build a “Retro Rally” P6 using an early 70’s Auto car as a basis. I also have a mid 80’s SD1 Vitesse to use as a donor car, I don’t have exact dates of the two cars as I only plan to collect them at the weekend.

During the preparation of the P6 the engine, gearbox, suspension will all be removed and thus during the rebuild stage I’d like to use the best combination of bits that I have plus any BUDGET (I don’t have money for an all out race or rally engine but, within reason, something’s could be bought) tuning parts that will help. The originality rules in Irish Retro Rallying are very loosely applied and I’d guess I wouldn’t be turned away even if I fitted the entire injection system off the Vitesse but I’d rather keep things more in keeping with the period as the possibility of doing other events outside Ireland can’t be ruled out.

Having read the thread “Improving Performance”

viewtopic.php?f=5&t=5668

Is it as simple as use the Vitesse engine with a 3.9EFI cam fitted and run it on re-needled SU’s?

Thanks

Tim

 

[chrisyork]

The simplest and cheapest performance upgrade is some more cubic inches care of a P38 Range Rover! No reason why you shouldn't use the SU's off the P6 (suitably re-needled) provided you're not after exploring the outer limits of the rev range! And with the sort of events you describe I'd have thought torque was more important than power. NOte that you will have to use the P6 (or SD1) front cover, which means you'll be buying a new cam to suit that front end and your capacity. The other advantage of this route is that you automatically get a cross bolted late type block.

Next on the list is a decent exhaust maniflod. There are currently two off the shelf sources, and of course you could get a bespoke one made up. The two sources are RPI and Classeparts. The RPI one is famously tight around the engine mountings, I have not yet heard reports of a Classeparts one actually fitted. These of course need a suitable system on the end of them, but you should be able to get that knocked up locally.

I would have thought that was the limit of what was really needed. I'd spend more time and effort keeping everything cool!

You definitely need an engine oil cooler. Neatest (but not cheap) solution is to omit the radiator cross member and substitute it with a V12 Etype cooler, which is long and thin and fits the space perfectly. You'll also need to upgrade the radiator - it can't cope in normal traffic, let alone competition. Cheapest upgrade is a three row core, but for competition use I might be inclined to go for one of Classeparts aluminium ones. And chuck the engine driven fan in favour of some electric ones for more horsepower, freer revving and better temperature control. You'll need to fit a radiator header tank while you're at it.

If you envisage a lot of low gera work you might want to fit a transmission cooler as well?

Please don't fit power steering, you don't need it after your suspension mods and you'll need a cooler on that too if you do!

Chris