mg midget engine 1500 swap ??

[timetraveller]

hi all
what would be the classification on the engine after the modifications
does the shape of the head alter the cylinder capacity to 1275 ??
or is it just a tuned 1098 with a better exhaust flow
neil

by the way george hurst i think im gonna go with a 1.75 exhaust system but thanks for the offer

[GeorgeHurst]

No worries Neil. I don't think the classification changes with regard to log book etc, but you should tell your insurance that it is a modified engine, and they will most likely want to know what increase in bhp the mods have made.

[twincamman]

hi all
what would be the classification on the engine after the modifications
does the shape of the head alter the cylinder capacity to 1275 ??
or is it just a tuned 1098 with a better exhaust flow
neil

by the way george hurst i think im gonna go with a 1.75 exhaust system but thanks for the offer

Altering the cylinder head doesn't change the engine capacity. You can tune the 1098 as much as you like, but unless you change the cylinder bore or stroke, it'll always be a 1098.

[timetraveller]

hi all
can someone tell me which would be the best gasket set to buy for the conversion

standard morris minor head gasket 1098cc or mini 1275.............??
where can i get a inlet manifold gasket to suit the lcb manifold

thanks
neil

[GeorgeHurst]

Have a look at minispares.com
They do a complete gasket set for the top end for about12 quid. You will need the 1275 gasket set

[bmcecosse]

It MUST be a 1275 head gasket - have you checked yet to see if there is clearance ? From the questions you are asking - I'm concerned you don't appreciate what's going on! If you get this wrong - you could do some severe damage.......

[timetraveller]

It MUST be a 1275 head gasket - have you checked yet to see if there is clearance ? From the questions you are asking - I'm concerned you don't appreciate what's going on! If you get this wrong - you could do some severe damage.......

hi
i do appreciate whats going on and know about the consequences which is why im asking these questions
from the outset there has been no complete set list of items needed and i havent done this before which is why im relying on you people who have done this before and made the mistakes to guide me through it in the correct manner

by the way and with all due respect posting 'have you checked yet to see if there is clearance?' doesnt actually mean anything to me so if your gonna post then post constructively and explain yourself better
if you have this conversion in your car then why not be helpful in listing ALL the parts required and any tips and pointers to set this up correctly

thanks
neil

[bmcecosse]

I have listed it over and over again - which is why I ask if you know what you need to do! And again you say you know what's going on. I mentioned earlier about checking there is 320 thou clearance - since you didn't query this at the time - I assumed you understood. There must be that 320 thou between exhaust valve face and head face - or the valves will smack the block.You also need 1275 rockers - may need to file the top of the water pump slightly to get clearance, and depending which era of head you get - you may need to block off the bypass stub on the water pump - or fit a pump without the stub.

[timetraveller]

I have listed it over and over again - which is why I ask if you know what you need to do! And again you say you know what's going on. I mentioned earlier about checking there is 320 thou clearance - since you didn't query this at the time - I assumed you understood.

ah confusion
320 thou clearance on the exhaust valves.....yes i remember that from a previous post however the head hasnt been delivered yet so i cant check it.

can you tell me where the parts are listed and under what heading/topic

if its a common occurence when people are asking about this conversion then it would be a good idea to post the procedure as a notice board sticky thats unremovable and people can not post comments or replies to it.
we have this facility on the ford100e.com site that i am a member of and it stops the same repeated questions being posted.

this is my first foray into tuning an a series engine....in fact its my first foray with AN a series engine,as from previous posts i was gonna get rid of it as i think its underpowered and put something a bit more powerful in but after reading a few posts and with a bit of encouragement from others it seems it is a very tunable,reliable,simple and highly underrated engine so if an engine swap is unnecessary then point me in the right direction and then i dont have to chop and change a perfectly good moggy

thanks
neil

[bmcecosse]

Only Mods can make 'stickies' - they have been asked many times in the past............ both for this and other useful threads........
Once you get the head - come back with any queries.

[timetraveller]

when using the top right search box
i cant seem to find a definitive list of parts regarding this conversion
does this conversion have a name
neil

[Declan_Burns]

Neil,
Just for info.
This shows what I used to sink the valves and it doesn't really take long. There are other ways I'm sure but this is the way I went about it.
1) Measuring the distance from valve to base of cylinder head. Take several measurements[frame][/frame]
[frame][/frame]
2) Sinking the valve with a valve seat cutter to 320thou (8mm)[frame][/frame]
Grind in the all valves-this takes a bit longer


3) I replaced the bypass stub with a stainless steel one as it was badly corroded-or block it off-mentioned above. It's a strange thread -I think 5/8"x 16 UNS (S=special)[frame][/frame]
You need to file a small amount from the water pump housing so the head sits flush with the block
You need the 1275CC head gasket
Replace the valve stem seals when fitting the valves.

4) You need to make up a transition piece for the heater valve or fit the older brass valve.You need to modify the bracket on the engine steady bracket-file a notch to clear the lower part of the transition for the heater valve.[frame][/frame]
You need a new thermostat housing and gasket. The one from a pre 1967 MGB is not bad but the angle on the one from Birmingham Morris minor centre is better. Part no 12M220. The MGB housing has to be dressed with a file to fit.
Some have just modified a minor bottom hose instead of replacing the thermostat housing.
Regards
Declan

[timetraveller]

hi

can i use the standard rockers if i re align them or do i have to use 1275 rockers

head has arrived so i will be inspecting it tommorrow and hopefully the fun will start there

thanks
neil

[bmcecosse]

The original 'pressed steel' 1098 rockers are better - so yes - if you are prepared to re-align them over the valves properly that is the best way to do it. I didn't have any problems with heater valve/engine steady or thermostat housing! You may NOT need to sink the exhaust valves - measure first - then decide.

[GeorgeHurst]

An alternative to the possible heater valve issue is to use one of these: http://www.minispares.com/Product.aspx? ... 696&title=

[Declan_Burns]

Quite pricey-£18.79 inc vat !
Declan

[timetraveller]

hi
received the head measured the valve clearances and miles away so head is currently in machine shop having seats ground out

i found this info which is relevant to this conversion and may be of help to others looking into it

http://www.calverst.com/articles/ch-cyl ... _%20no.htm

thanks neil

[bmcecosse]

Yes - well --Mr Calver and his wild extravagant claims for power increases are well known ! The idea is not exactly new - I fitted a genuine Cooper S head to my 998 racing engine more than 40 years ago now - it worked extremely well! I'm surprised your head is 'miles away' - many can be used 'as is' - or just need a light grind-in to get the 320 thou - which in any case still leaves the thickness of the gasket and the valve gap at the rocker 'for safety'. However - some heads - including the one I am using at present - need ~ 40 thou taken off the exhaust valve seat to get a good clearance. In this case - a 40 thou spacer (washer!) should be fitted under the exhaust valve springs to keep the compression in the springs same as before. As it's a 1098 engine - don't be tempted to use double springs! You don't want to rev it over 6000 anyway. If the valves look 'pocketed' - it is possible to un-pocket them using a small pointed grindstone in an electric drill. It's also WELL WORTH spending a little time down the exhaust valve throats - where the gases have to squeeze past the valve guide boss and the 90 deg turn in the throat. It's only a few minutes work to open up this area to double the cross section - which relieves congestion at this point! Don't take anything off the actual guide - just the boss and the head directly opposite the boss. And - do use 15 thou gap on the exhaust valves - 12 thou on inlets is ok.

[timetraveller]

info was more to help distinguish origin of cylinder head if your unsure of what your buying

as for my cylinder head well not really miles away but not near the 320 thou needed they measured 265 thou so after grinding out ill have to space the valve springs approx 55 thou for everything to be ok

thanks
neil

[bmcecosse]

Crikey! Not heard of anything more than 40 thou necessary before - hope they measured correctly. It is only the exhaust valves you need to do - don't do the inlets!