1275 from metro turbo
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hi guys i've this spec of engine:
mg metro sport head with the metro turbo exhaust valves
metro turbo block in stock specification
gearbox standard metro turbo stock
metro sport cam
standard rocker
jonspeed decompression plate 9cc
t3 from the metro turbo

if someone can help in what do i miss or should be better to do to do a reliavable engine with about 100 bhp at wheels

cheers styves as tieeger

Edited by AlexB on 29th May, 2007.

I am sure that the MG metro chambers are the same volume as the mety turbo 21.4cc so no need for a decomp plate (horrible things anyway .. better getting the head modded).

If I am right the 9.4:1 CR will be fine upto about 10psi with an intercooler which should see you meet your goal. But you need that intercooler!!!

The money you save on the decomp plate should go towards a 4 pin diff which will be essential if you want the transmission reliable. So long as the rest of the box is in good order and you don't drive like a prat then it should hang together reasonably well.

Only thing I think you may have missed is that to run the mety turbo ex valves you need the larger bore guides too ... if your going to that trouble your far better off getting a genuine turbo head IMHO

Every day is a school day ...........

How fast and how expensive ...... the same question...

Agree with Roger, what ever you do DONT use a decompression plate...opening a can of worms springs to mind...LOl

BENROSS on here is a top bloke and will sort your head chambers out to lower your CR.

Personally I wouldn't bother using Metty turbo exhaust valves just run some good quality non-sodium valves...Im using the minispare stainlesss race valves, there nice valves and not too expensive.

You may want to run an orange clutch plate, as it will grip better than a standard plate.

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1/4mile in 13.2sec @ 111 terminal on 15psi

ok i will try what you say. thanks for help
cheers styves

there is no difference between a decomp plate and running with the pistons down the bore as you wants to Matt!:)

except an extra sealing face to deal with.

Thought Matty was convinced by JohnK's and my sums saying not necessary anyway for the K conversion ... might be wrong.

Every day is a school day ...........

How fast and how expensive ...... the same question...

André I was think more along the lines of having to use an extra head gasket. Especially when theres other options (like opening the head chambers out) available.

An option not (yet available/tried and tested) with the K head.

Roger still undecided..... Im more thinking along the lines of 8.8:1 CR. Ideally an SA crank and 970 rods...but funds won't allow that....Lol

Shortening the stroke a little using S rods seems more practical (from money point of veiw), and bringing the block down to my desired CR. Still thinking of flat tops as I could re-use them if I decide to go higher compression in the future.

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1/4mile in 13.2sec @ 111 terminal on 15psi

Decompression plate will also further mess up valve train geometry. Stay away!

I can't see what's wrong with decompression plates. The name of the game is squish, so if you have the chambers of the plate matched to your head and bowls and use thin gaskets, there should be no problems. Whether you can order one of these or not is up to you to find out. Getting one made is not as awful as it sounds. That's the route I aimed to take but I found that I could scoop out a huge chamber with my die grinder which did the job. Forget inlet valves, you need exhaust flow IMO.

I'm running a N/A engine again and I reckon that the best course of action is getting a shitty overskimmed, useless race head and whacking it on a decompression plate. A fat one. Get some longer rods (crossflow, etc) and turn them down to the right length.

I don't like the idea of short rods as squish is very important. I suppose if you could be arsed, you could grind some off the caps and then bore a shorter distance.

I reckon the winner is (jim?) who had circular chambers. You just set the mill up and drill them out. Not wanting to go into detail about how stuff burns under higher compression, the old weslake beak chamber shape is less significant. If you ask me, the cirular chambers are the way to go....

As soon as I've got my fat cheque from the taxman, I'm going K head with no blower.

Got my mega gearbox sorted.

Bugger off, I'm getting there.

how does it mess up geometry on the valve train ?
if the valve head ,and pivot point stay the same ,isnt the only change in the 1 or 2 mm more you have to wind the tappet adjuster down ?
the arc over the valve head stays the same as it was ?
am i being a numpty ??lol

Medusa + injection = too much torque for the dyno ..https://youtu.be/qg5o0_tJxYM