Need help for engine specs
Turbo Mini Forums

Hi there guys,
I am going to rebuild my engine and use the following:
15cc forged pistons, 1.5 roller rockers, 29cc chambers, 30mm exhaust valves, 35.6 inlet, phase2 camshaft, drive belt conversion kit, Std T3 turbo, std gerabox, std crank. Do you see any problems with this compination? what do you suggest? What about c/r?
Thank you

maybe use 1.3 roller rockers with the cam as thats the recomended on there website, although i know people on here d use the 1.5's i think.

My build thread..

http://www.turbominis.co.uk/forums/index.php?p=vt&tid=542985

yup, i like my 1.5's with it.

Well with 15cc pistons and 29cc chambers your going to have a low CR which suggest lots of boost (compounded by your choice of staying T3) but you also state your going for a std box. This sounds a little odd to me. Either use that boost to get big bananas which means you'll have to do something about the box / drops / diff or build a higher CR motor which will be nicer to drive on lower boost as you are limited to around 140bhp (guestimate) with the standard box even if it is rebuilt really carefully with all the right bits and a cross pin diff.

Comes down to what you want the car for as always.

Every day is a school day ...........

How fast and how expensive ...... the same question...

Do you guys ever really have issues with gearboxes? Here in Aus there are people putting 150hp (at the fly) through standard 4 synchro boxes and jsut not thrashing the crap ut of them.

I know of many poeple using N/A big bore minis making around 120hp at the fly using stock boxes.

How much power do you expect from that setup?

<edit> Whoops missed the 140bhp bit above yeah I'd say that would be your limit, for the setup.

Edited by slinkey inc on 29th Apr, 2007.

Supercharged 1964 Morris 850 - Now 1330cc with 7psi.

I don't like 1.5 with phase2 , it does give only a few above 4500/4800 for slower boost respons, and less torque before these revs .
you aren't talking boost and intercoooler
what does this set up give in term of cr?
I have sorted about 7.3 thios eem to be quite too low, I would up this to 8.2/8.5
(45cc head volume (15 piston 3 head hgskt 3 deck 24 cyl head))
about the gearbox, it will live if you treat it correctly, this is why some aren't survive and some others do it

Yeah the helical cut gear in the standard box is probably stronger than a straight cut set, but its the drops and diff that will fail under high bhp and spirited driving.
Its then a case of what gear ratio and final drive you want? and that’s when you will need to upgrade the box to the straight cut set.

its the side loading of the bearings that damages the standerd gears, especialy the drop gears.
stright cut loses the side loading, so is better on the bearings.
thats how i understand it anyway.

My build thread..

http://www.turbominis.co.uk/forums/index.php?p=vt&tid=542985

spot on josh, the heicla is stronger routine i dubt very much, with spirited driving on tuned 1275 NA engines ive seen quiet afew broken teeth on the input gear, none on a sc set, only willys blue atomic bomb he drives around.

but looking at the engine spec i would go for sc drops and gear set with 4 pin diff and a good 3.1 final drive, that would last for donkeys with out much greive, how ever go helical route you would need to be very kind to here at slow speeds if you want it to last.

always looking for them bigger bunches of bannanas

Oh yes, heavy standing starts are more or less a no-no if you stay helical and have around the 140bhp mark. I normally limit boost in first to actuator setting (normally 4.5psi) if staying helical. Even then a good bit of wheel spin at the lights could well be the end of it!!

I've broken teeth under my 122bhp NA on standard box as well ..... but it does get more abuse than a choir boy.

Every day is a school day ...........

How fast and how expensive ...... the same question...

the way i see it is, whats the point in spending money and having 100+ bhp in a mini and drive it like a granny??
makes no sence to me! lol
what cc are you going to have?

My build thread..

http://www.turbominis.co.uk/forums/index.php?p=vt&tid=542985

Josh .... I see your point but, ask yourself this question.

"I use my car everyday as my only means of transport and my family live 3 hours away, can I really live with a SC box and drops?"

If you answer yes then your either deaf already, never drive an SC boxed car on a long motorway journey (trust me, don't) or a little bit prone to self harm!!!

Every day is a school day ...........

How fast and how expensive ...... the same question...

i see your point roger but, thats one reason why iv got two mini!! lol i supose im lucky as i have the space and not having to pay loads of bills etc (yet)

cheers
josh

My build thread..

http://www.turbominis.co.uk/forums/index.php?p=vt&tid=542985

Hi,
Josh .. You don't have to drive it like a Granny all the time, just be kind to it
Cheers,
Gavin :)

VEMs Authorised Installer / Re-seller. K head kits now available!

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Visit www.doyouneedabrain.co.uk

My Mini build diary

Ive only got 10cc dished pistons and want to run 10 low - 15 high boost. What size chambers will i need on the head or is 29cc the limit?

Sorry not trying to highjack the thread just wondered is all!

Rich

what cc is your engine?? 1293? by any chance?
if so then it would be...

1293cc
10cc dish
2.8 hg
pistons flush with deck
29cc chambers in head

8.73:1

thats what i worked it out to be anyway! lol

(rich, if your interested in a head with 29cc chambers and ported, check the for sale section on this site as i have one for sale now)

My build thread..

http://www.turbominis.co.uk/forums/index.php?p=vt&tid=542985

On 29th of Apr, 2007 at 06:53pm RogerM said:
Josh .... I see your point but, ask yourself this question.

If you answer yes then your either deaf already, never drive an SC boxed car on a long motorway journey (trust me, don't) or a little bit prone to self harm!!!




Cheers Roger, im really looking forward to my near 300 miles journey to Newquay now! If I keep asking you to repeat yourself then you know why....Lol

https://www.facebook.com/pages/Fusion-Fabri..._homepage_panel

www.fusionfabs.co.uk



1/4mile in 13.2sec @ 111 terminal on 15psi

clubman turbo take Fabs advice

On 30th of Apr, 2007 at 05:54pm josh_tacon said:
what cc is your engine?? 1293? by any chance?
if so then it would be...

1293cc
10cc dish
2.8 hg
pistons flush with deck
29cc chambers in head

8.73:1

thats what i worked it out to be anyway! lol

(rich, if your interested in a head with 29cc chambers and ported, check the for sale section on this site as i have one for sale now)

Edited by richminiturbo. on 1st May, 2007.