21 replies to this topic

[Kevwana]

Hey guys, looking for some help, I am meant to be picking up a 1275 mg metro engine tomorrow to drop into my recently acquired rolling shell..

Engine was advertised as follows

Mg metro 1275 engine -Including gearbox

1.5 roller rockers / Ported inlet / Polished chambers

Hi pressure oil pump / Piper 300 camshaft

Belt driven vernier timing gear

Comes with starter /alternator 

 

The more I've read on the piper 300 cam I realise this seems massive overkill with the limited mods carried out. What I need to know is will running this cam have caused any damage to engine or just had adverse effect on performance, basically am i likely to be picking up a goosed engine ! Am driving 4 1/2hrs to collect and dont want to waste my money...so would appreciate any feedback ...

 

Thanks

[Midas Mk1]

286 is max for the road, you'll hate it on the road past that to be honest. 

 

266/276 is a far more usable range, usable in terms of being faster too for more road conditions.

[Cooperman]

To run an engine with that cam will require it to be revved at well over 7000 rpm as peak power doesn't arrive until around 690 rpm (from memoory asn I don't have the cam graph to hand).

Now if it is a properly prepared race engine which means fully balanced with a wedged and treated crankshaft and better pistons (like Karl Schmidt or Omega), centre main bearing strap, lightened steel flywheel, ARP big-end bolts, polished and stress relieved rods, etc., that might not be a problem, but personally I would not fit that engine without fully stripping it and re-assembling after checking everything and accurately measuring.

I certainly wouldn't buy it for use in any sort of road or rally car.

The 1.5:1 rockers will move the power even higher up the rev range and knock off some bottom end torque.

It will most definitely need a close ratio straight cut gearbox and a very low final drive ratio (FDR) in order to keep it on the cam.

It is a race spec cam and one can only hope that the engine has been built for the narrow power/torque band and high revs.

[nicklouse]

We have steady answered this in your other topic.

You don't want that cam and you don't want the rockers.

[Cooperman]

It rather depends on what you are paying for the engine and whether you can see/hear it running.

Personally I wouldn't pay more than about £500 for that lot as the true history and build quality are unknown.

It will have to be stripped and fully checked before installing and if you are to keep the cam and use it only for racing it might need substantial additional work. A full-on race engine can easily cost over £10,000 with the gearbox once all the parts capable of giving the power and sustaining the ultra-high revs are included plus the expensive specialist labour.

If it is for a road car it would be better to buy a 1275 engine in need of rebuilding and DIY with the correct parts to optimise the engine for your intended use, rather than to buy an engine which has either been built (well built??) for racing then driven as intended, or put together by someone who doesn't even know how to select the correct cam for the application.

Please be very careful here.

[Kevwana]

To run an engine with that cam will require it to be revved at well over 7000 rpm as peak power doesn't arrive until around 690 rpm (from memoory asn I don't have the cam graph to hand).

Now if it is a properly prepared race engine which means fully balanced with a wedged and treated crankshaft and better pistons (like Karl Schmidt or Omega), centre main bearing strap, lightened steel flywheel, ARP big-end bolts, polished and stress relieved rods, etc., that might not be a problem, but personally I would not fit that engine without fully stripping it and re-assembling after checking everything and accurately measuring.

I certainly wouldn't buy it for use in any sort of road or rally car.

The 1.5:1 rockers will move the power even higher up the rev range and knock off some bottom end torque.

It will most definitely need a close ratio straight cut gearbox and a very low final drive ratio (FDR) in order to keep it on the cam.

It is a race spec cam and one can only hope that the engine has been built for the narrow power/torque band and high revs.

 

 

It rather depends on what you are paying for the engine and whether you can see/hear it running.

Personally I wouldn't pay more than about £500 for that lot as the true history and build quality are unknown.

It will have to be stripped and fully checked before installing and if you are to keep the cam and use it only for racing it might need substantial additional work. A full-on race engine can easily cost over £10,000 with the gearbox once all the parts capable of giving the power and sustaining the ultra-high revs are included plus the expensive specialist labour.

If it is for a road car it would be better to buy a 1275 engine in need of rebuilding and DIY with the correct parts to optimise the engine for your intended use, rather than to buy an engine which has either been built (well built??) for racing then driven as intended, or put together by someone who doesn't even know how to select the correct cam for the application.

Please be very careful here.

Thanks 'Cooperman'  engine is already out so can't be heard.. your replies on my last topic highlighted that was obviously unsuitable cam for this engine with its limited mods.. I just wanted to try and establish if it would be a case of replacing cam with something more suitable or if damage to engine would likely have been caused already ?

Thanks for your input. much appreciated..

[Kevwana]

We have steady answered this in your other topic.

You don't want that cam and you don't want the rockers.

I'm aware from last topic's replies that this cam is unsuitable for purpose, thats not what i was asking, was asking if it was likely to have caused any damage running this cam or would it just have resulted in poor bottom end.

[Dusky]

Like I Said in your other thread : if it was used as it should it will have seen 7k rpm regularly and thus I wouldn't expect it to be very good.
However, its a trend to overcam an engine and keep the revs low in the mini scene. So it might as well be a very good base engine to just swap the cam in.
I D take a compression tester, attaching a starter and turning it over to test the compression is easy enough with the engine out. Or you could ask to remove the cylinder head and inspect the bores to get an idea.

[carbon]

A race cam in a 1275 used to its full potential will give the centre main bearing a very hard time.

 

If the engine can be inspected before purchase then it might be possible to check 'nip' on centre main bearing. With one of the centre mains bolts slackened off you should be able to get a 3 thou feeler into the gap between cap and block.

 

If there is no gap then the centre main housing may be oversize as result of hard use. Before using the block this would need to be sorted.

[ACDodd]

This engine is fit for rebuild nothing else.

Ac

[racingbob]

yes when buying it allow for a full rebuild i had a piper 300

 

in my hisotric race mini for a while and revved to 8000

 

so it dont last long

[Kevwana]

Thanks for your input guys.. Decided to give this one a swerve, have seen a complete car advertised a lot closer with a 1275 "bored out to 1350 with high lift cam", gonna go have a look but I at least know what questions to ask re engine rebore/cams etc cheers

[Carlos W]

Thanks for your input guys.. Decided to give this one a swerve, have seen a complete car advertised a lot closer with a 1275 "bored out to 1350 with high lift cam", gonna go have a look but I at least know what questions to ask re engine rebore/cams etc cheers

 

1350 is a very odd size. 

 

Id' be asking who built it and whether it was off set bored. 

[Cooperman]

How do you get a 1350 cc A-Series? At + 0.060" it is 1330 cc and that is as far as you can go without offset boring. To get 1350 cc would surely mean an offset-ground crankshaft using 'S' size (1.625") big end journals. That would be an odd thing to do.

 

The best thing the OP can do is to get a 1275 or 1293 block, with crank, rods and head and build it to his desired specification for the intended use. That way there will be no nasty surprises.

 

I once had a newly-built 1380 brought to me which had been re-built 3 years earlier by a so-called 'expert engine builder' (hence out of warranty) and it had just been started and was throwing out oil and smoke. It turned out that it had not been offset-bored, but the bores were an average of 0.005" oversize for the pistons. The owner had to buy another block which then had to be offset-bored. It was an expensive lesson.

 

If you buy a 'race or rally prepared' engine be very careful because if it has been driven as intended it will probably be 'shagged out' and in need of a full re-build.

[Kevwana]

Have asked for paperwork for engine build, so will see what they come back with,
http://www.ebay.co.u...=STRK:MEBIDX:IT
Engine is in car still and running/driving so will go and have a look as is not far from me, if there is no proof of build spec will prob leave it and try find a standard block/crank to start with and go from there..