Hello
Can I convert my 998 cc engine to 1275cc or 1275cc+

Any idea?

 

If you mean can a 998 become a 1275 by boring or stroking, the answer is no.

You can remove the 998 from the trans and install a 1275 though.

BTW, I have a friend that has one for sale cheap - $650 with trans. It should be inspected and refurbished before install. It had excellent compression and oil pressure when I checked it.

 

do you have any pic of it ?

 

Minimad, where's the engine located?

Steve

 

Lakeland FL

http://www.sunshineminis.org/forums/...ic.php?t=12472

 

Can i use this --> Half Engine Kit or Short Engine Kit



^^

 

Yes, but shipping from the UK is a killer.

I'd prefer the short kit cuz you'd wanna spec your cam for intended use and put in a new oil pump anyway. Plus this kit you need a 12G940 (big valve) cylinder head to take advantage of the displacement. Add in an 1 3/4" SU, intake manifold, LCB manifold and a larger RC40 exhaust too....it adds up fast.

Your alternative is to take the 998 you have and build it with the Stage 1 or 2 kit offered. The prob with stock engines is breathing. While there is no substitution for displacement, intake, exhaust & head mods can significantly help the 998.

 

^^ thank you for your help

 

Just to add fuel to the fire, Putting a stage one kit on your 998 and some head work and you basically have a basic 1275 type of powerband.

Everyone wants 1275s so your not alone but I have driven some wickely strong 998s, Tony M in Florida blew past me in my 90hp converted 1275 MPI mini in his 998 mini, Okay, he is a lifetime british car mechanic but it shows what can be done with a Normally aspriated 998.

Sure saves a lot of money to not change engines.

Cheers. Peter

 

So, as one with a 998 and a stage 1 (1-1/2" SU, Mini Sport manifold, LCB) already in place, your recommendation to me would be to replace the head with a 12G940 instead of replacing the 998 with a 1275? 'Nigel' runs pretty good, but is still a little flat on exceleration. I'm thinking it could be a timing issue or something like improper dashpot oil damping or some other SU issue. I still need to explore further. BTW, this is just a 'road' car; not one used in races, autocross, etc.

 

You don't mention what exhaust system? Air cleaner?

 

K&N wannabe filter, dunno the exhaust - I don't know the car's history and am not familiar with the Mini exhaust systems.

 

the RC40 is the "gold standard" for Minis, either single muffler or twin depending on how much noise you like. I've found the twin perfect for a sporty sound w/o sacraficing performance.

 

Dumb question: How can I identify an RC40 exhaust? Looking under the car, I've got (well, it has) twin mufflers and single 2" SS tailpipe. And to me, it sounds pretty sweet.

 

That's what i've done to mine and my mechanic tells me it runs like a stock 1275. I've also replaced my exhaust and have a k&n CAI. That's about all I've done performance-wise.

 

The muffler on an RC40 is stamped "RC-40", clever, huh?

Larger pipes do not mean better performance, necessarily. The LCB comes in two diameters for large bore & small bore motors, for example. The larger pipe will slow exhaust gasses down in a small bore application. The A-series is very dependent on maintaining certain flow characteristics. Same goes for intake mods.

You should obtain a copy of David Vizard's "Tuning the A-series" engine or "How to modify your Mini" and read through it before embarking on the project or shelling out major $$$.

 

LCB sizing per MiniMania:

 

Head info:

http://www.minimania.com/web/SCatago...2/ArticleV.cfm