Bore flex - Myth or Math.
Turbo Mini Forums

yes marina alegro blocs are different in casting, correct me if I'm wrong but I think they also have a thicker deck, they have an oil filter as an mpi bloc.

It is only the Marina that uses the Mpi oil filter head. The Allegro uses the same block as the late 1275 GT. THis is the block Vizard say is the best block to use. There are at least three, possibly four different 1275 A blocks, not including the S ones.

Vegard,
I dismantled an Allegro last month and it had an A+ with mpi filter head...
it is certainly a good bloc as it was high milage (120 000km) and bore bearings crank were in very good condition, could have been reused as this.

I have never seen an Allegro with an MPI filter block. I suspect that the engine was not original and explains the good condition.

http://www.twin-turbo.co.uk
http://www.hillclimbandsprint.co.uk/default.asp

A man without a project is like a like a woman without a shopping list.

I must agree with Ben. The Allegro was never sold with A+ engines.

I'll look for engine numbers to know were is it from.

the block could have been fitted in the after market, i now dsn shipped about 100 of these blocks abroad some were about 8 years ago.

i think one major problem to look for as far as 1380 goes is to makes sure the engine has been looked after in a previous life eg regular antifeeze changes because i did have a block which broke through into the water way when being bored out because the previous owner never kept up regular antifreeze changes and the block corroded in towards the cylinder liner. this i can see to be a major factor so always have a look in the water pump whole and see if its a nice clean rusty colour or has gone very bumpy and a deep orange ( if it is avoid like the plaque).


but think about it all these so called engine builders like avonbar med ect are all now doing 1380 turbo kits weres before they didnt , wether thats because the thought there was a flex issue i dont know but they are getting on the babd waggon.

my next build will be a 1293 but my 1380 still looks spot on so she will go for another year. and thats now 6 years of thrashed to an inch of its life 2 of which were high cr turbo build running pretty close to det and still looks spot on.

always looking for them bigger bunches of bannanas

That's a good point. In Norway everyone use anti freeze whereas in Uk it seems as noone does. Lots of blocks and heads I've picked up in the UK have been very corroded internally.

Not sure am still mearly an amature but wasnt the allegro cast out of a higher grade of iron also. May be thinking of something else but could be fact. Correct me if i am wrong.

i suspect that steve at MED reads the threads on TM

antifreeze does 2 jobs ist its a antifreeze and 2nd its a anti corrosion inhipter.

the anti corrosion ihipter is what deteriates with age and thats why it should be changed every 2 years.

you look in a block which has had it changed regular and its like new in the water ways.

just because its summer you still need antifreeze. also it raises the boiling point of the water as well which can be upto about 110 115 deg c.

always looking for them bigger bunches of bannanas

Infact, antifreeze reduces the boiling point of water.

http://www.redlineoil.com/products_coolant...&coolantFlash=1

Edited by Vegard on 26th Oct, 2006.

http://www.team.net/sol/tech/coolant.html

I'll get some pics up in the morning with what i know about a+ blocks, hopefull others can pull more info together to get a full picture.

I've seen the future and tbh its Pie

vegard i sugest you try boiling a 50 50 mix and let me what you find.

im sure with antifreeze and a holding pressure of 10 psi boiling point is raised to 115 deg c ish

always looking for them bigger bunches of bannanas

Why at 10 psi?

Holding water at 10 psi should raise the boiling point to approx 118 degrees on its own, if the 50 50 mix is boiling at 115 degrees it suggests to me the boiling point has lowered.

Edited by Joe C on 27th Oct, 2006.

Quote "The function of the coolant base is to extend the liquid range of the coolant. In a 50% mixture, the glycols will lower the freezing point to about -45C and raise the boiling point to about 115C"

I suspect this is at atmospheric, knowing a little about glycol and its use.

http://www.eetcorp.com/antifreeze/antifreeze-faq.htm#q3

Edited by Sprocket on 27th Oct, 2006.

[quote=mini13,27th of Oct, 2006 at 09:58pm]Why at 10 psi?

because the cooling system is pressurised. i think most rad caps lift at 13psi as standard

I'll have a look at my bores when I have my 1380 to bits.

Pure water has the highest Cp of all and so putting anything in it will reduce that. Off the top of my head, when you boil a mixture, the lowest boiling stuff comes off first...distillation. It's how you separate things!!!! Anyway, if you want to get good coolant. Freeze a load of distilled water into a block and put it in a plastic bag. Add a bit of salt to depress the freezing point and then whack that in your car. The water will have it's dissolved gases removed in this process, hence no oxygen. Assuming your system is full to the top, no air will be admitted and corossion won't happen. I tend to shag engines before the corrosion is a serious issue.

Stu

Bugger off, I'm getting there.

seems like the original topic has expanded [ 'spose thy're doing the same thing !? ]
What about you chemists/physicists starting your own thread

Anyway , after reading all this and Vizard [ turbo+nitrous sections ] and talking to as many top engine builders as i could , Seems to me that for big power /boost to go over +0.040 is not worth the chance you've got a perfect block.
Seems that Modern top quality turbo pistons use a 4-ring pack to stop blow by , so any small amount of bore flex
would be shite

Carl

Edited by Sprocket on 29th Oct, 2006.

WTF????

Double post but i only pushed the button once!!!

Honest mister

Edited by Sprocket on 29th Oct, 2006.