8 replies to this topic

[new_van_man]

Hi,

I have an engine out of an MG Metro (c-reg). I intend to rebuild this, I am goin to strip this down completely. But before i do I am trying to get a handle on the level of work required.

I am hoping to be able to get the engine to be very relaible and drivable rather than for performance. Efficency is also an issue and would like to keep the engine as efficent aspossible. Hence the main reason for rebuild, whilst I am interested in improving the power output I am on a limited budget (approx 1k max for engine and box).

Cylinder head:

Skim head.
Replace all valves, seats and guides and springs. Is there any advantage in going for bigger valves than standard? or is this just more unnecessary expense?
Maybe replace rockers for high lift? (this is quite an expensive modification IMHO so what would be the benefits of this? improved power, more fuel consumption, effect on overall efficiency?
Clean waterways and chemical clean of head. Currently waterways in head are full of a white crusty powdery substance? Any ideas what this is? Also the engine used to get hot under idle, but was fine as going along.....

What wear should i be looking for around the valves?
How best to clean of any carbonisation of valves and head? Wire brush on drill or grinder or too aggressive?

Block:

Skim block (if required)
Bores (either hone and leave as 1275cc or bore out to 1293cc) - Obviously boring out to 1293 means new pistons and is going to eat into my budget so what condition would the bores need to be in to not justify boring out? Does anyone have any pictures of shocking bores vs good bores so i can compare to my own block? What effect would high lift rockers have on different bore of 1275 vs 1293?
New followers
new oil pump and filter
Regrind Crank (again what signs of wear should i look for? what would worn bearings imply?
new water pump (i know this knackered)
Camshaft hope to reuse the MG metro one? Is this likley to knackered?
New timing chain and gears
New gaskets
New rings and pistons if required due to rebore?
new bearings.

I take it if the bores look ok, then removing the pistons and crank is not recommended? or should i remove and replace the rings and bearings only, with a check of the crank?

Gearbox

I was going to attempt rebuilding the box myself but I think now it maybe worth getting a professional to do this. I was going to add a central oil pick up and get it reconditioned. If i have to go to 1293 will i need to upradte the diff? If so would i get away with teh cheap one mini spares do? Hoping to get this done for 300 odd quid leaving 700 for the engine, is this realistic?

Does anyone know an idea of rough costs for each step so i can try and decide which bits are necessary and those which would be a nice to have?

I know theres a lot of questions here and i tried to be as clear as possible, but not having rebuilt an engine before it kind of the blind speaking to the educated....

many thanks in advance

[MRA]

Not if you want any reasonable amount of reliability, even using a kit, this figure will fairly quickly be used up. now you could get a cheaper rebuild kit, using budget parts and reusing any parts that are not completely scrap....... however you mentioned reliability as a key point.

[new_van_man]

Not if you want any reasonable amount of reliability, even using a kit, this figure will fairly quickly be used up. now you could get a cheaper rebuild kit, using budget parts and reusing any parts that are not completely scrap....... however you mentioned reliability as a key point.

What would you recommend? Obviously it is quite a lot of effort to go to so I would like it done properly. How much would i need to increase my budget by in your opinion to get something which is reliable. Reliability is my key criteria.

[mk3 Cooper S]

Concentrate on the engine.
Crank,shells, thrusts etc, pistons and bores, cam and bearings and timing gear.
Gearbox, ensure all is good - send to Guessworks!!

The head etc you can be less concerned about as it is fairly straightforward to remove and work on whilst the engine is still in the car. Personally I would not bother with roller rockers.

[new_van_man]

Concentrate on the engine.
Crank,shells, thrusts etc, pistons and bores, cam and bearings and timing gear.
Gearbox, ensure all is good - send to Guessworks!!

The head etc you can be less concerned about as it is fairly straightforward to remove and work on whilst the engine is still in the car. Personally I would not bother with roller rockers.

Thanks for your advice, will ditch the rockers. Just a quick question though what am i missing in my list of works that would make the engine unreliable? Everything effectively going to be replaced bar the cam and crank (regrind?), and depending upon condition of bores and pistons maybe these or maybe not?

[MRA]

using old pistons & bores is pretty much false economy, unless you have so little wear, a few 10ths (0.0003") is not an issue however I have seen blocks that are supposedly "new" with almost 8 thou of extra bore to piston clearance.... they wouldn't last 30 days

Using an old camshaft again is false economy, do you have the exact followers in the exact positions that they where fitted to the second hand cam ?? if not then elevated wear will occur, primarily on the lobe nose, followed by rapid failure of the followers.......

You want reliability but you want a budget engine, unfortunately the two do not match very well

[bmcecosse]

Certainly avoid high lift rockers - roller or otherwise! Lots of expense for very little gain

[MRA]

offset rockers give good increases in torque, they don't necessarily show up as high BHP gains, however I know what I would prefer

However I would have to agree that sticking with a good standard set will allow you to spend your hard earned coppers in a more worthwhile direction

[new_van_man]

So in short my best bet seeing as engine is now out of the car,

is to strip down and bore the block out to 1293 and buy new pistons and rings as a definate, reuse con rods but with all new bearings, check and regrind crank; also to replace the cam(i take it you would recommend this also) was going to replace followers for definate anyway. is it worth the extra money going for a duplex timing chain or is the single one ok? (budget of £465 - 500 inc machining and all new parts - no new cam)

intend to replace all valves and seats etc in head. (budget of £220 - 250 inc machining and all new parts)

Can i still use the old pushrods and rockers if straight and not to worn? Would it be prudent to get a new sahft for the rockers?

And will send gearbox for reconditioning also. (£330)

Is tehre anything I have missed? Will replace oil and water pumps too.

The other thjing is that my engine is missingit engine number tag on the block, does this matter? Will it be stamped on the inside of block? I know it came out of C reg MG Metro as i took it out when bought it as few years back (10 to be precise!)

With regard to pistons, i had a look on mini sport, and they have a choice of two one with a compresson ratio of 8.8 to 1 and 10.1 to 1. I take the higher the compression ratio the better? Is this correct? or is there not much in it apart from price?

Sorry so many questions, am just trying to price up project before i start spending and it snowballs out of control and am unable to finish it. I got a fair bit of welding needing doing to so cant go crazy on engine costs so need to be efficient wuith the availble coin.

Many thanks for your help people is very much appreciated.