10 replies to this topic

[chris211083]

Hi Guy's,
My wifes mini has come to the point where where we needed a new engine or to rebuild our current one. We got a rebuilt 998 engine and gearbox off ebay for £550. This will replace the original 998 engine and gearbox currently in the car but I've decided to up the performance a bit. The car is a 1988 998cc saloon and was bog standard when we bought it and had been stored for a long time. I recommissioned it and we have used it since Feb this year. It's the wife's everyday car and she loves it to bits so we decided to spend some more cash on it to give it some more oomph. We bought a sports exhaust+LCB and alloy inlet manifold with a K&N in the airbox and I changed the needle to suit and she loved it but wanted more poke. So with the rebuilt engine on the ground I thought it would be nice to change the cam while the engines out. A Minisport CA3 cam arrived today and I plan to fit it tomorrow. I've also ordered the Specialist Components 5 port EFI kit which should arrive on Friday. I ordered the EFI kit as I was getting annoyed with the sub standard parts(ignition/rubber bushes and mounts etc) and wanted the car to be more reliable and be tuned more easily. I also know how much better it is over dizzy's and carbs. I'm a Triumph man and have gone through the same thing on my Spitfire with the final result(efi) being the best mod Ive done.

So. Whats my question?

After the engine is run in and everything is known to be fine, I want to upgrade the head. I've been told the 12G295 head is the one to use on the 998 engine but how much of an upgrage is it over the standard 998 head both in standard form???

And does it just bolt on in standard form?

Next which is better when professionally ported, a standard 998 head or the 12G295 head both professionally ported? I'm not after screaming the nuts off it but She who must be obeyed needs more oomph so i'm asking which head to use with minimal fuss.

Finally what do you guy's think of this Ebay listing.
http://www.ebay.co.u...t_4156wt_1271

Or am I better getting a standard 12G295 head and getting some one to port it like minisport???

looking forward to your reply's.

Cheers,

Chris Sherrington.

Edited by chris211083, 23 August 2012 - 01:04 AM.

[coopdog]

yeah that link is very expensive,
i would just keep an eye out for one they always pop up for a good price

[danny79]

very interesed in this topic also,
will you be starting a build trend.

very curious how the Specialist Components 5 port EFI kit proforms on a 998 and what type of preformance you get.
been looking at this kit for a long time but anybody who has started a trend on this forum has either failed to update or not completed project.

make sure you get lots of pics.

[lrostoke]

The 12g295 is a highly recommened head, but worth remembering they have not been in production for a long time, so difficult to get a good one.
They do have to be modified...the combustion chambers are bigger than a standard 998 head so the head needs skimming to bring the compression ratio back up...BUT the head will need to be checked first because its possible work as already been done.
I also believe you need a smaller water pump pulley or it fouls on the head.

Another option is the 12g940 (1275 head)....various opinions on this one, but more readily available but more work involved

[coopdog]

The 12g295 is a highly recommened head, but worth remembering they have not been in production for a long time, so difficult to get a good one.
They do have to be modified...the combustion chambers are bigger than a standard 998 head so the head needs skimming to bring the compression ratio back up...BUT the head will need to be checked first because its possible work as already been done.
I also believe you need a smaller water pump pulley or it fouls on the head.

Another option is the 12g940 (1275 head)....various opinions on this one, but more readily available but more work involved

nah just take the water pully off ad grind down about 2mm from the inner edge and it shouldnt touch,


also what is the Specialist Components 5 port EFI kit?

Edited by coopdog, 23 August 2012 - 08:39 AM.

[chris211083]

very interesed in this topic also,
will you be starting a build trend.

Yes I probably will, as I said it's the wife's car but we both love it. I'll also be putting up forsale the parts we take off. I should have the EFI fitted and functioning the same day it arrives. I'll start a build thread just for the SC 5 port kit with lots of photo's.

Here is a link to my own Triumph car thread.
http://sideways-tech...is-sherrington/

Does anyone know which head would perform better a 12G295 full ported and worked or a standard 998 mini head fully ported and worked???

Chris.

[chris211083]

Ok the Specialist Components 5 port EFI kit.

http://www.twinkam.c...aid=SC208B.001

Its a complete Electronic Fuel injection System that basicly replaces a carb and you dizzy and gives you unlimited adjustability. There are no moving parts so nothing wears mechanically. The ECU is fully adjustable and can be mapped by yourself running a LC1 wideband sensor. So any change you make to the car (exhaust/head) you can easily adjust the fuelling without having to swap needles etc. Also the ignition doesn't need to be a curve like a dizzy must have so you can get more power and more torque because you give the engine the ignition advance it needs. Starting is easier with efi and there is no dizzy to get wet or cheap parts that fail before they should, I'll be removing my dizzy completely. The EFI will also allow you to run cams that before were too lumpy to use everyday. It also allows you to get max mpg as well as max power so you get the best of both worlds. This system with the 45mm throttle(998 throttle size) is good for 100bhp, the 50mm version will match a weber carb for performance on top end but will out perform it in the low and mid range because of the adjustability.

In short it's the *******. However it's not a performance upgrade!!! It simply allows what you have to be used to its potential. It does not solve port robbing etc it just allows you to get the most from your motor no matter what state of tune it's in.

[Ethel]

Modding a standard 998 (CAMwoteva) is much more hassle as there's loads more metal to remove. Even then you can never get it as good as a 295 before you break through the other side. You could do a 12g940 but the ports will be a little big to retain full low rpm driveability and you'd most likely have to pocket the block for the valves with a hi lift cam.

If your new engine has flat top pistons getting the CR up will be a bit easier.

[Foxy10]

while im here...

http://www.ebay.co.u...1#ht_500wt_1203

http://www.ebay.co.u...1#ht_500wt_1203

:)

[chris211083]

Foxy Im one of your watchers. Unfortunately Ive hit a problem with the rebuilt engine. It wont turn very well, I need to start a new post for this though.

Chris.

[Foxy10]

The green one sold last night, red one still available http://www.ebay.co.u...1#ht_500wt_1203