14 replies to this topic

[pinkmini99]

Just pick up a short block off eBay. Spec are as follows
74mm pistons so 1400cc
276 Kent cam which I will change to a piper 300
Center main strap
Turbo oil pump

Going to do a few little things like change the cam. Lighten followers super light flywheel

Just need some idea on what sort of head to run

[nicklouse]

First thing I would do is strip it and check it, then I would bin the turbo oil pump unless you are building a turbo as it is not needed and caused more issues than you want.

Head well you need to workout the CCd you need for the cam you plan and what the Pistons give. Then get a head done to suit.

[pinkmini99]

First thing I would do is strip it and check it, then I would bin the turbo oil pump unless you are building a turbo as it is not needed and caused more issues than you want.

Head well you need to workout the CCd you need for the cam you plan and what the Pistons give. Then get a head done to suit.

How would I go about this ?
The chap I got the block off said somethink about 24cc and it is written on the block.

Any advice would be great new to the engine building side of mini ownership.

[Carlos W]

 I would bin the turbo oil pump unless you are building a turbo as it is not needed and caused more issues than you want.

Great advise, unless you're running a turbo or an oil cooler all a turbo oil pump will do is sap power and pump oil past the pressure relief valve.

 

 

Have a read of the post on here by Cooperman.

 

http://www.theminifo...pression-ratio/

 

Put yourself an arbitrary number in for the head, like 24CC and see what CR you get. 

 

As Nick says, you've got no idea of the standard of the build, cleanliness etc, You're aiming for the kind of clean you'd want if you were having surgery.

[carbon]

The pistons do look like they have a very deep dish. Could be 24cc, in which case this was likely run as turbo unit. The bad news is that if the volume in pistons/block really is 24cc, then this block is unlikely to work as basis for normally aspirated high output.

 

With a 300 degree cam you're likely going to need compression ration of 12.0:1 or more to make best power on 99 octane fuel. With a 1400 that's a total of 32cc combustion chamber volume (head & gasket & pistons).

 

With 24cc in the pistons/block, plus 3.5cc for gasket that leaves a volume of 5.5cc in the head. There's no A-series head I know of which can take that much skimming.

 

On the other hand if you're planning a turbo unit then it should work fine. But not with a 300 degree cam.

[pinkmini99]

Ok thanks guys

So what your saying is turbo or supercharger it.

The chap I did buy it off races metros and seam to know his stuff.
He did say there was a little room to take it off the block as well as the head.
I'm hoping it put it in to my pickup so don't really want to go down the turbo route (don't want to chop up the bulkhead)

Also I've been looking on the inter web and kad say 74mm pistons with standard con rods is 1399cc but with 86 MM. Con rods would be 1480cc
Would this help me or make it worse?

Or would I be best to move the short block on and start again ?

Looking for over 100bhp at the wheels

Edited by pinkmini99, 28 July 2016 - 03:12 AM.

[Spider]

Just looking at your new short block, I agree with Carbon that it does look to have LC Pistons fitted, but this is only our guesses. Before loosing sleep or money on th project, CC the short block to actually measure what it is you have and have some real hard numbers to work from before deciding what is possible and which direction you should take.

 

I would also recommend in the highest terms to forget a 300 degree Cam and consider something maybe as much as about 285-ish for the street at the bigger end, even shorter to make it more driver and road friendly (and enjoyable you'd find).

 

I recently did a 1380 for a friend, fitted with a 266 type of Cam (from the US though) and that was able to develop 80 HP at the wheels on the rollers (roughly 95 at the flywheel), though they all ran out of time and is still not set up to get the best from it, so could see maybe another 2 or even 3 ponies on top of this. Very road drivable and very quick indeed.

Edited by Moke Spider, 28 July 2016 - 05:39 AM.

[carbon]

100bhp at the wheels for a road going mini pickup?

 

Think that to be tractable that would either be forced induction or very trick head such as 16 valve.

 

And careful attention to suspension set-up if you're going to use it on wet roads, as there is not much weight over the rear wheels.

[pinkmini99]

[quote name="Moke Spider" post="3406638" timestamp="1469684165
 
I recently did a 1380 for a friend, fitted with a 266 type of Cam (from the US though) and that was able to develop 80 HP at the wheels on the rollers (roughly 95 at the flywheel), though they all ran out of time and is still not set up to get the best from it, so could see maybe another 2 or even 3 ponies on top of this. Very road drivable and very quick indeed.[/quote]

I've got about 80ish at the moment with my 1310 with a 276 cam ,Webber and played with head. Which is in my clubman. Which I have a lot of fun with but I need more power in my pickup lol for track days

[pinkmini99]

100bhp at the wheels for a road going mini pickup?
 
Think that to be tractable that would either be forced induction or very trick head such as 16 valve.
 
And careful attention to suspension set-up if you're going to use it on wet roads, as there is not much weight over the rear wheels.

I hear what your saying I've had the arse end out a few times with a standard 1275 metro lumb in it but was fun. As soon as I lowered it and put some gas filled shock and some A032R on it. It was like a different animal.

[Icey]

(don't want to chop up the bulkhead)

Supercharging won't need that and there are manifold and turbo combinations that don't either.

[Dusky]

300 deg is full race.
If you s Ever Drive it on the road I d Go for a 544 or an ac dodd cam. With a 300 deg cam you' ll idle at 2k and wont Even get off the line under 3k.

[pinkmini99]

300 deg is full race.
If you s Ever Drive it on the road I d Go for a 544 or an ac dodd cam. With a 300 deg cam you' ll idle at 2k and wont Even get off the line under 3k.

I know. A friend of mine has got a 300 cam in his and it still drivable on the road

[nicklouse]

 

300 deg is full race.
If you s Ever Drive it on the road I d Go for a 544 or an ac dodd cam. With a 300 deg cam you' ll idle at 2k and wont Even get off the line under 3k.

I know. A friend of mine has got a 300 cam in his and it still drivable on the road

 

unlikely to be honest.  but with some clever trick mapping and electronics and injectors big cams can be tamed a little. but still I would not use mine on the road.

[Dusky]

Depends what you call drivable. Maybe "manageable" would Be the better word?