Fast road 1293 turbo - aprox 150hp
Turbo Mini Forums

Hi, am embarking on my first engine build soon and need a spec to work to.

purchased a metro turbo engine as a start last weekend and have started to srip it ready.

I have read many previous posts using the search... yay for me ! and have come up with the spec below. It is my very first go at a spec so be nice ! I have put question marks where i think things need looking at.

Any thing you guys see thats wrong or could be better please comment, thanks guys

EDIT - Have edited the spec with the advice i have been getting on here, more advice welcome !


Fast Road 1293 Turbo Engine & Gearbox Spec – Aprox 150hp 10-12psi

*Where “Standard” is used, this means metro turbo standard parts*

Block + Crank
1275 metro turbo block
bored and honed to +0.020” (1293cc)
Plateau honed, refaced
11 stud head drill & tap
New oilway screw in plugs
New core plugs
Under-crown cooling - needed ?
Centre main strap
ARP mains bolts
Crank ground to next size IF Needed, hardened, cross drilled & balanced
New crank bearings
New cam bearings
Oil fed thrust washers - Neccecary ?

Pistons + Rods + C/R
?? compression ratio - any thoughts?/where do i find the AF Racing spreadsheet ?
MED +.020” Cast omega pistons 10cc dish - enough dish ?
Omega rings
Standard rods lightened
ARP rod bolts
Rods/Pistons Balanced

Cam + Rockers
Avonbar phase 2
Duplex timing chain
High grade followers
1.3 (After reading a post by avonbar) ratio Roller rockers - opinions ?

Head
Will prob use standard turbo head to exchange
for pre modified head, Any reccomandations ?
OR Benross to modify turbo head ?
Drilled for 11 stud fixing
ARP studs & nuts

Oil Pump
MED High Capacity

Gearbox
Toughened allen head gearbox fixings - TurboDave ?
Straight cut drop gears
Mini spares clubman S/C gear set
All new bearings etc.
Minispares cross pin diff
3.2:1 (possibly?) final drive ratio - i need to work this out but any reccomendations for a fast road setup ?
Centre oil pickup
Adapter for oil temp gauge

Flywheel + Clutch
MED Lightened flywheel and backplate - Machined for better clamping - TurboDave ?
Grey pre-verto clutch

Turbo
Refurbed Standard Metro T3 Turbocharger (as I have one !) - ok or not ?

Edited by Arge on 8th Oct, 2009.

Will my project ever be finished !!? hopefully you guys can help !
Its only been like 10 years in the making and I'm only just assembling my engine!

1) I wouldn't grind the crank as a matter of course. Have it measured and checked first, it may be OK at standard size.

2) I probably wouldn't bother with 5/16 block to box bolts either.

same as tom, i defo wouldnt bother with the block to box bolts. just use some caphead screws, ask Vegard

TurboDave does some toughened allen head gearbox to block bolts. they are much easier than redrilling the block/box

As for final gear ratios, have a look here:

http://www.guess-works.com/Gearbox/Technical/ratio.htm

Will help you plan your gear set etc.

Benross and Turbo Phil both do proven cylinder head modification.

You may as well get your rods lightened while your at it

Re. "can you offset bore at this size"

Yes, but is it really necessary ??? Vizard doesn't recomend it until very large bores.

Also, is your block one of the factory lined ones ??? If so I would definately NOT recommend offset boring as you would be making the liner very thin on one side.

edit - also you couldn't offset by much, if you went for say the standard 0.010" offset with a +020 rebore (which is only +010 per side, you wouldn't actually be reboring one side... (end edit)

Re. dish size - it all depends on the CR you want to run and what work is done on the head, what the deck height is etc.... Use the AF Racing spreadsheet to work it out.

Edited by Rod S on 6th Oct, 2009.

Schrödinger's cat - so which one am I ???

loads of stuff there you dont need ..
you DO need ..

strong pistons ,(although i think a few have run a good amount of boost on the stock pistons ,nick ?)
good cam ,
decent ported head ,
big intercooler ,
straight cut gear set ,
cross pin diff
well put together
..bingo.

Medusa + injection = too much torque for the dyno ..https://youtu.be/qg5o0_tJxYM

10cc cast MED pistons - Yep enough dish, the head can be modified to suit compression.

A duplex timing chain will be fine for the job!

From what ive seen alot of people dont bother with rockers, at least I think dont opt for the 1.5 ratio (got a feeling 1.3 is better suited?).

As for s/c drop gears and s/c gearset - minispares are great, the clubman gearset is the one you want.

Finale drive - really depends what you want to use the car for really? I thin ka good mix of short and tall is a 3.2 FD, good for track racing and not bad for dragging. All down to preferences really.

Flywheel and backplate - MED every time. Search for a post by TurboDave regarding machining a small amount off the backplate mounting lugs, to optimise clamping force.

The rest sounds pukka and the same spec as mine! I have a Benross head and can highly reccomend his work, he's on this forum!

Turbo Phil has also done plenty of proven heads and other parts.

These guys do other worthwhile work such as manifold to port matching and t3 turbo elbow porting.

If you have the cash/time/skills to do so, might be worth looking into alternative turbo setups? Although 150 can be achieved with a t3, perhaps not at 10psi though? Not entirely sure.

Get Megajolt, its brilliant and so worth it.

Seeing as you're in Reading, get Stuart Gurr at VmaxScart to get it all tuned up for you.

i used 1.5 rockers and it worked well enough for me

id oil feed the thrust bearing as its easy to do, we get 1-2 cars a month in the garage with fubar thrusts due to grey covers, its also not good for the block and pistons when they do go.

i recon megajolts the easyest way to go if you want that power reliably

my coputer just spazzed out soz for the double

Edited by MONSTER HEDGEHOG on 6th Oct, 2009.

Thanks for the replys so far guys, some really good sounding advice so far. Knew i could count on you guys to sort me out !

Have updated the origonal post with the advice i have read but there are still a few things that need ironing out so to speak. Need to get this spec sorted before i start to send bits away to be machined etc.

thanks guys

EDIT
Richminiturbo - You say your spec is basically the same, what sort of power and torque are you producing ?
How are the road manners, good for a fast road mini ?

Edited by Arge on 6th Oct, 2009.

Will my project ever be finished !!? hopefully you guys can help !
Its only been like 10 years in the making and I'm only just assembling my engine!

I havnt actually finished mine yet haha.

I'm expecting to crack 150bhp, 170 would be nice I guess, planning on running 15psi though.

As for on the road, I can imagine it will be a bit of an animal.

If you have the cash an LSD would be nice!!

mine is a similar spec but a 1380 and a med head.

im not sure on bhp, but at 10 psi its a handful on the road and feels quicker than my last car (s2 elise)

If you're aiming for ~150HP then I suppose you would be running about 0.7bar boost. A CR around 9:1 would probably be in the right area but CR is quite subjective. Some people go more conservative than others. What are your plans for an IC?

As for the T3, it is quite antiquated now but will still produce the required power. The current trend hs been to use the GT1752 for that kind of power. Again, it's up to you if you want to go with a quicker spooling, more efficient turbo.

The majority of people now forgo under-crown cooling. It was an absolute pain in the arse on my engine, but that's a small bore. It doesn't cost alot to do though, so you may want it for peace of mind.

I would stick with standard rockers. They are an easy part to bolt on at a later date. Your build will more than likely go over budget so you may regret spending on non-essentials like rockers at an early stage.

As said previously, a 3.2 is a good compromise on FD. I found a 3.4 a pain on motorways but I do tend to overtake alot.

The spec you have chosen looks like a very good starting point and you seem to have done a fair bit or reading

Edited by GaryOS on 6th Oct, 2009.

On 12th Nov, 2009 Paul S said:

I think Gary OS has taken over my role as the forum smart arse

From your updated first post, the spreadsheet is here,

http://www.afracing.co.uk/CR.xls

Copy it to your hard drive !!!

Schrödinger's cat - so which one am I ???

Have just finished stripping the engine and all looks good except 2 halves of the big end bearings (different rods)

see pics....





That looks pretty bad to me! all the crank journels look good and smooth, just wondering what may have caused this and if it will be a problem for me using this as my donar engine ?

Also do the rods look ok ? they are smooth, just have this, what looks like wear on them....

Will my project ever be finished !!? hopefully you guys can help !
Its only been like 10 years in the making and I'm only just assembling my engine!

Top halves (in the rod itself) or bottom halves (in the caps) and which cylinders ???

Never seen them that bad and still running.

Looks like most of the the lead bronze has gone as well as the lead indium, but to one side only.

Possibly rods installed the wrong way around on those two (it can be done and that is the result I would expect)....

Schrödinger's cat - so which one am I ???

they were both the halves in the RODS, not sure what cylinders, will look tomorow. - Edit cylinders 1 and 3

I was under the impression the engine hadnt been apart before but could be wrong

EDIT - Duh ! in the rods not the caps ! silly me

Edited by Arge on 9th Oct, 2009.

Will my project ever be finished !!? hopefully you guys can help !
Its only been like 10 years in the making and I'm only just assembling my engine!

Even more strange then,

You would expect most damage to be in the rod half of the shell, not the cap half.

Obvious wear to one side only is usually a sign of mis-alignment, hence my suggestion the rods might be the wrong way around - but I would expect it to show on the top half (rod part) of the shells, not the bottom half.

Have a look at the sides of the rod (adjacent to the shells) for any signs of wear, especially uneven wear.

Schrödinger's cat - so which one am I ???

cold be the crank journel tapered?

Sort of ran out of time tonite but will have a good look tomorow and report back

Will my project ever be finished !!? hopefully you guys can help !
Its only been like 10 years in the making and I'm only just assembling my engine!

bent rod

"Turbo's make torque, and torque makes fun"

"did you know you can toast potato waffles?"

Sorry, is that a deffinate or just a possibility ?

If it did turn out to be a bent rod, I have a set of a+ rods in an old engine. Are these the same, could they be used ?

Will my project ever be finished !!? hopefully you guys can help !
Its only been like 10 years in the making and I'm only just assembling my engine!

Surely it's up to Rod to announce that

Edited by apbellamy on 7th Oct, 2009.

haha quality apbellamy,

any input on the busted bearings though ? as for me this is a more pressing matter ! lol

Will my project ever be finished !!? hopefully you guys can help !
Its only been like 10 years in the making and I'm only just assembling my engine!