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My new engine

Posted: Mon Jun 22, 2009 12:56 pm
by sgrant
MED are suggesting I look at their RC engine which, coupled with my Weber and bored out to 1380cc, should make 110-115bhp at the flywheel.

This is a *lot* more power than I was thinking of. Am I going to need to worry about box/half-shafts/anything else at that output? And will I end up having to go round the rest of the car uprating brakes and so on?

stephen

Re: My new engine

Posted: Mon Jun 22, 2009 4:36 pm
by Mknight702
Homer Simpson mode on "Mmmm, power" Homer Simpson mode off.

I'm guessing that at that level things are likely to go bang much more quickly, halfshafts and gearbox probably first. After all, the halfshafts already snap like carrots and the gearbox was designed for somewhat less power in the A35.

Re: My new engine

Posted: Mon Jun 22, 2009 8:46 pm
by erictharg
It all depends how much of that power you use and how often! Best way to preserve the drive train is a sympathetic right foot. Whilst the gearbox and halfshafts are not the strongest, bear in mind the car is lighter than a Midget. As long as you don't do endless drag starts they'll last fine if on good nick. I would suggest staying away from the 1380 version as that needs more serious offset boring than just a 1293 or 1340 (+020 & +060 thou). Having said that , given your healthy passion for understressed reliability, you may want to go for the uprated Peter May halfshafts. Halfshafts go without warning whereas you usually get some sign that a gearbox is on its way out. Thing is, with a 45 and a good cylinder head, plus decent compression ratio, it's going to be hard to get less than 100HP.

Re: My new engine

Posted: Tue Jun 23, 2009 8:19 am
by sgrant
Unless I just swap to a ported head and 1.5 rockers and leave everything else alone? In which case i'm looking at 85bhpish presumably?

Re: My new engine

Posted: Tue Jun 23, 2009 9:58 am
by brian
I installed an MED XT before Le Mans and had managed to put about 1000 miles on it to shake everything down. I subscribed to the erictharg view that a careful right foot would prolong the life of the rest of the drivetrain.
However, the night before departure I took the car for one more drive. Coming out of a roundabout in 2nd, a wheel hit a pothole on the 'beautifully maintained' (according to our local council) road. In consequence, my right foot shot forward on the accelerator and a distinct 'snap' sound was followed by a complete lack of drive.
I spent most of the next day trying to extract the broken halfshaft and didn't manage to get hold of a driveshaft until mid-day on Friday.
I've been talking to Frontline about their uprated chromalloy driveshafts but didn't know about the Peter May ones. If I do get them I'll stick an LSD in at the same time.
Brian

Re: My new engine

Posted: Tue Jun 23, 2009 12:04 pm
by sgrant
I heard about that; sounds like a bit of a mare. I'm sorry you couldn't have made it.

I wish I understood the difference between all the MED engines. I can see it all on the website, but I struggle to work out the differences, not helped by the fact that they don't quote any approximate power figures.....And why is the kit £900ish, but the built engine £2.4k, but you only save £400 if you do the engine build yourself? I'm a bit confused there. What's not in the kit?

s

Re: My new engine

Posted: Sun Jun 28, 2009 6:04 pm
by Mknight702
Stephen,

One of the reasons that the DIY kits are so much cheaper is that the self build starter kits do not come with the cylinder head where as the built engines do. That would suit me fine as I am happy with my head. If you do decide to have your own head ported let me know and I can see if I can find the number for Paul Ivey who makes the Rimflo valves.

Matthew

Re: My new engine

Posted: Wed Jul 01, 2009 9:38 am
by sgrant
Thanks Matt; i'm just talking to a few folk at the moment about getting a new ported head. Someone called Bryan Slark? Seems to know what he's doing....

s