15 replies to this topic

[ozz1]

Ok, so I'm currently driving a 1978 Austin 1000 with a later (998) engine in it, of which the year is unknown (it has a later verto clutch) and I'm contemplating a new engine which I've been offered at a very good price. I would rebuild my current engine and put it back in, in the summer.

 

I'm 18 and currently have a very good insurance deal, I have declared my stage 1 kit and air filter and it hasn't raised my premium at all. Whilst I enjoy having to push a 998 to get the most out of it I'm looking for something a little bit more 'exciting', I still want it to be 998 for insurance reasons- and above all I love the way they rev!

 

If I upgrade to aftermarket performance components it will raise my premium, but if I use parts from other minis I'd like to think my premium wouldn't increase quite so dramatically. For instance, is the compression ratio on all 998's the same, I heard it was higher on some later minis? Is the rocker lift the same on all minis, I heard some cooper s rockers were 1:5.1? And is there a slightly higher lift 'standard' mini cam, I heard some metro cams mildly resembled the BL 731 rally cam? Maybe a 1098 head- how would this change the compression ratio?

 

Question is, if you had to cherry pick parts, from other minis, to create a relatively 'insurance friendly' engine, how would you go about it?

Edited by ozz1, 18 December 2013 - 02:44 PM.

[filski]

Will not be able to give you technical answers, but my set up was

 

- electric points

- 12g295

- Twin Carbs 1.1/4 with correct needles and springs (+k&n)

 

That kept me happy next thing would have been new cam

 

but if you want FUN while keeping insurance low then i would suggest not to do the above but invest in

 

- 10" wheel set up

- uprated cones

- better shocks preferably adjustables

- rip out carpets, rear seats (you could even take out passanger seat :) ), sound proofing from the floor (trsut me will save you heaps of weight)

- get rid of that yeallow foam stuff in the engine bay

- fiberglass bootlid and bonet

- basically save weight anywhere possible the above is the cheaper / free option

 

good luck

[lawrie124]

I would give it a good service, fit elec ign and matching coil (simonbbc or similar) then get it tuned by a mini specialist rolling road.

 

That'll do for starters, and all insurance friendly.

 

... and THEN I'd look at filski's wheel/suspension mods, which are a good idea if you aren't running 10's already.

[DomCr250]

I personally preferred the 998's and 1098's over the bigger engines.

 

Your head is probably a limiting factor, a 12G295 is a great addition but they are now expensive,.  You could use a 12G940 head and get the exhaust valves sunk further into the head (no block machining) - it would probably be the same cost as getting the 12G295 skimmed if it's not already had it done.  You might need hardened exhaust valve seats too ...so price that into the equation.

 

1099 (1100) head wont make much if any difference to what you have already.

 

The MG metro can was supposed to be better than a standard cam (I'm not 100% sure of that), but swapping a cam in a 998 is still not easy and you might need to think about oil pump drives - it's still probably an engine out task.

 

Best suggestion is above, electronic points and a good rolling road session, lots of feedback on the forum on who to use, from where you are minispeed is a close by and I have a few good report on their rolling road work ...I think they offer a basic setup for less than a full session?

[TimmyG]

If the engine you already have in the car has a verto clutch i’m pretty sure that means it’s an A+ engine, which i think all had the high compression ratio of 10.3:1. I know mine did.... To double check if it’s an A+ the front of the engine block should have strengthening ribs on it. All the later engines also had the worst rockers as standard, as far as lift is concerned.  The sintered ones.  I measured a best of 1.21 at full lift but i used them anyway because i had large enough valves/enough airflow and didn’t need more lift ;- with a small bore engine you can provide too much valve area too quickly with a high flow head AND high ratio rockers can actually reduce torque (and therefore power).  One or the other should be fine, i.e. you could potentially use 1.5 rockers with a standard head and realise an improvement, if those were the parts you had.....

Based on what i’ve researched about cams, the 731 is a bit of a damp squid and should be avoided. To quote Vizard’s book “install a 731 cam, lose all the bottom end power and gain almost nothing at the top end”

The MG metro cam is the one to use if you’re using standard cams, and is probably the one you’ve heard about as it has the same exhaust lobe as the 731, but reduced intake timing which makes it very drivable, but free-revving.  Exactly what’s good for fun road use which isn’t surprising given that it was designed for that purpose :)  Incidently i wouldn’t go looking for a 2^nd hand one when you can get a re-grind from Kent cams (KC500), something you’d be wise to do anyway with a second hand one.

As you have fitted a stage 1 kit already (and had it set up properly on the rollers), the cylinder head is the priority for derestricting s so i would concentrate your efforts there. I believe the 1100 heads were ever so slightly better but you'd probably be better off doing a re-con and improve your head and get better results with simple and cheap mods around the valve area.

Another option is to fit an MG metro head...this is what i did, along with a full rebuild and pocketed block (apparently not always necessary so the head could be a bolt on mod).

Built properly, or even as a bolt-on if the engines in good nick, you should/could be looking at between 60 and 65bhp with this set up. Makes for a very fun and economical mini !

Hope this helps!

[ado15]

Not all A+ 998's are high CR. If you have flat top pistons, they were the factory high CR option (10.3:1). Dished top were low CR (8.3:1).

 

All factory rockers were supposedly 1.245:1.... in reality, they were all over the place!

 

I think others have covered the cylinder head options pretty well. Any change to a 12G295 (Cooper 998 or Midget/Sprite 1098) or 12G202 (1098) will require skimming a fair bit off to get the CR back. They both have larger chamber volumes than the 998. 295 heads fetch silly money and are often cracked!

 

I too, have heard of good results from using the MG Metro cam in a 998. But I don't have any direct experience of this.

[ACDodd]

The best way to get the best from a 998 is to get it to produce more torque. This means capacity. I usually fit a 1098 crank and +0.060" pistons to give 1149cc. The extra stroke makes a proper torque pump out of a small bore engine. I would also use a more modern cam too get a broader spread of torque. Older cams are short on lift and high on overlap lift meaning a cammy delivery and higher exhaust emmissions. Aim for a cam low on overtlap lift and high on lobe lift/ relatively short on Duration. Also aim for valve size, intake diameter is key, the bigger the better. An 80lft torque small bore long stroke big intake valve engine hhas has big engine feel. Don't fit the 940 head as the intake ports are too big for a torque pump. The best combinations in my experience are a flowed 295 with stock intake port and a 33.2mm intake and 26.4mm exhaust valves. Keep metal removal from the ports to the minimum, work the valve throats and seats, torque in abundance is to be found under the seats. As for a cam aim for Piper BP255 Kent 246, SW5-07, or from me the ACD - RT or ACD - RS (RS currently out of stock - most popular grind!) profiles. Use Stock A+ rockers with all cams for maximum punch between 2 & 5K rpm.

 

Go with 9.5:1 CR with SW5-07 & ACD - RT profiles and 9.75:1CR with Piper BP255, kent 246, and ACD - RS profiles.

 

AC

Edited by ACDodd, 18 December 2013 - 04:18 PM.

[ozz1]

Thanks for such in depth advice, given me some fantastic ideas!!

[jayy2895]

if you dont mind me asking
how did you get insurance at 18?
classic car insurance?
ive been look at insirance iswell but no luck
cant find any companys that will insure me at 18 on a classic car

[ozz1]

if you dont mind me asking
how did you get insurance at 18?
classic car insurance?
ive been look at insirance iswell but no luck
cant find any companys that will insure me at 18 on a classic car

Try Aviva online, strangely gave me the best quote out of anywhere- with less than a years driving experience I'm paying £1100. I have friend (17) with 1098 clubman paying a similar price through Aviva as well, £1000-£1300 seems to be fairly standard. Adrian flux isn't too bad either if you can bear having a black box...

[Vipernoir]

Swapping the crank will certainly get more performance, but it isn't a 998 any more !

 

My warm 1100 is pretty much the same spec as my warm 998 (both have a big overbore, 12G295 head & MG Metro cam but different compression ratios and inlet manifolds) and the performance is utterly different.  The ultimate power is probably about the same, but like you say the 1100 is a torque monster.

[Laundrymike]

You'd be surprised what difference the gearing/final drive will make...downside is even more noise and lower top end

[jayy2895]

if you dont mind me asking
how did you get insurance at 18?
classic car insurance?
ive been look at insirance iswell but no luck
cant find any companys that will insure me at 18 on a classic car

Try Aviva online, strangely gave me the best quote out of anywhere- with less than a years driving experience I'm paying £1100. I have friend (17) with 1098 clubman paying a similar price through Aviva as well, £1000-£1300 seems to be fairly standard. Adrian flux isn't too bad either if you can bear having a black box...

[jayy2895]

are you insured as the main driver? or just a name driver ?

[ozz1]

are you insured as the main driver? or just a name driver ?

Main driver!