17 replies to this topic

[cbyrne]

hi im looking for more torque from my mini without going mad a mate of mine has a 1275 on carbs and my mini is quicker, saying that do im using cyclo octane boost. if i tapeered the throttle body for more air flow would this help? so far my mini dose 105mph at 5200rpm. any help is welcome

cbyrne.

[jaydee]

Honestly what you first need is some head porting, the spi heads dont have actually a good flow, believe me, that has a massive influence on torque.
Another point, torque has nothing to do with top speed, its the BHP that can increase the capability of your engine to reach higher revs in the top gear.
Torque gives you more acceleration.

[cbyrne]

would it be better if i jus replace the head??

[AndrewJ530]

Grab a copy of david vizard's 'Tuning the A-Series Engine' and have a go at porting a spare head yourself. Pretty self explanitory and you save a load of money.

[cbyrne]

im looking for a head cheap but no one has one ang if they do they wont post to eire!!

[Dylan8660]

I have an mpi head available, €60.

[cbyrne]

I have an mpi head available, €60.

im looking for a spi head or 1.25 roller rockers

[Dylan8660]

It doesn't take much to convert it, a couple of drilled holes and a 5/8 tap.

[cbyrne]

so if you do the work how much we talking??

[Sprocket]

It doesn't take much to convert it, a couple of drilled holes and a 5/8 tap.

Please explain, as I think the MPi head will fit SPi no problem

[cbyrne]

hi sprocket long time no see. im just thinking would the mpi head not have a diff set up to the spi??. my plan is to sent it away and get it fully flowed

Edited by cbyrne, 02 October 2009 - 10:36 AM.

[Dylan8660]

The difference in the heads is the temp guage position and the heater take off. the heater take off has been blanked and needs drilled out (if the spi needs it?), to fit the temp guage you need to drill the head at the posistion of the bottom bolt of the alternator bracket through to where the thermostat sits and tap it to 5/8. It can also be retro fitted back to mpi by using a 5/8 bolt as the bottom bolt.
I have a 5/8 tap but not the right drill size for it. Pop in if your ever down this way and I'll show you exactly how simple it is and provide tea.

[Sprocket]

The SPi needs neither the heater take off nor the temp gauge sender hole

[Dylan8660]

So the only difference between mpi and spi are the holes for the alternator bracket, mpi/spi head for sale €60

[bananaman]

Does a straight swap of an MPi head onto an SPi make that much of a difference?