New Engine spec
Turbo Mini Forums

Hi I have never owned a turbo mini before and am new to this site,

however I have been out in turbo Tims on many occassions and GOD do they shift.

After owning a 112hp 1450cc on a dcoe, I am now after more power so need some advise from as many people as pos with varied engine specs

I love the power delivery of normally aspirated as I love playing on roadabouts but to get big power is an expensive game

SO the big question is what would be the best TURBO engine spec to go for to keep some drivability off boost and give smooth delivery, with the most power possible.

I know the 1293 can run 20psi + but what about the other CC?
Some info on cam choice and head would also be good

Cheers Jase

This is pretty much a well known spec that does the job: (cut/pasted from another post)

Remember a few basics:
Any post '86 block has the 'turbo' bearings.
Turbo and nat-asp rods are the same
Turbo gearboxes are the same, except for a slightly larger (and VERY expensive) 1st motion nose bearing and slightly different FD than the standard 1300 A+ gearbox.
Heads are the same, except turbo has 'special' exhaust valves and double springs.


So!
1) Get a 1275 metro block bored to 1293, and prepped along with new cam bearings, cooling mods, acid dipped, cleaned, etc.
2) Set of omega 'turbo' cast pistons
3) ARP Rod bolts
4)Avonbar 'turbo' oil pump
5) Avonbar phase 2 Cam with new followers timed at 108-109 degrees
6) SC/CR gearset
7) Trannex (not minisport) 4 pin diff
3.44:1 FD for 10" or 3.6 for 13"
9) SC drops
10) re-ground crank if needed (doesn't have to be crossdrilled, wedged or bladed!) fitted with steel flywheel, backplate, organic cllutch and grey coverplate
11) drilled clutch cover to release the heat from standing starts
12) 'MinTec' floating primary gear bush to avoid seizure during standing starts
13) large (28cc ideal) chamber head, with 35/29 valves - but with large seat width on exhaust valve. Larger valves will be better - but thats scope for future work!
14) Payen BK450 head gasket (standard Rover 1275) with standard headstuds at correct torque (no more!!!)
15) Renault 5GT water cooled turbo fitted to modified manifold, manifold ports matched to head
16) Carb modified as per this link
http://www.manchester-minis.cwc.net/technical/turbo-carb.htm
17) The intercooler selected and installed as per this link http://www.manchester-minis.cwc.net/techni...ntercoolers.htm

By the time you build this, an electronic ignition retard will be on the market for under ?300 which will sort out the ignition.

If you build all that, and put it in a light car, I GUARANTEE you will have a mini that will run sub 14's on a regular basis once you've mastered the launch, and at least 5.0-5.5 seconds 0-60.

oh, note i haven't included 1.5 rockers in the list... That's because mine has turned into a pig (which is probably acceptable for most - but not me!) since fitting these. No-one has yet done a decent comparison, but if you really wanted 1.5 rockers, then go for a softer cam - ie kent 500 / piper 255 to retain off-boost drivability...

Edited by TurboDave16V on 10th Aug, 2004.

That engine spec sounds good.

Also I had a look at the website on the links, that is really useful cheers

Just one question, in step (1) you mention cooling mods, any more info please? Is this grinding the block next to the water pump to allow more water around the back of the cylinders?

yep, but also pulling out all the core plugs and removing any casting flash that may be impeding coolant flow...

use a deep cast impellor water pump 2 core rad 6 blade fan oil squirters under the pistons to keep them cool, cross flow water cooling ,ceramic coatings on everything that gets hot , tubular exhaust manifold ,fuel injection etc etc
where must the line be drawn !!

------------------------

fastest turbo mini at york raceway in '97 ! 13.901 @99mph aah those were the days!

Thanks for that dave I have a budget of 3 grand for the engine and box so, do you think there are any other things that could be upgraded for that money,

I am going to morspeed on friday with tim to see what he can offer as a kit any opinion

on the 500 cam were is the power band

one last thing which re-mappable ecu do you advise using and is it possible to run throttle bodies

Thank Jase

I run the Emerlad ECU, dave one DTA, both do pretty much the same job, It's really down to what rolling roads you have near you, and which system they know best.

injection on a 5 port head is a nightmare. But is soemthing turbodave is looking into long term

Team www.sheepspeed.com Racing