Technical Bigger valves

[minijohn]

Thanks - I didn't realise that . I obviously would have found out soon enough , but better now than later . Anyone know how much it needs to be lowered by ??

Mase -the Punto 75 head , complete with cam , inlet manifold , exhaust manifold & TB cost me £70. I'm back to the scrappy on Saturday to get the Punto 75 downpipe to give me a cheap 4-2-1 exhaust. A bit of welding will soon match it up to the rest of Cinq exhaust system

John

 

[custard]

have a look here minijohn

 

[minijohn]

Thanks - I can never find this stuff when I search
John

 

[smokeme]

Ok you guys are getting confused here.

The difference in hp between the 60 and 75 is the cam not the port size, the only reason the ports are bigger is so the injectors can spray onto the valves. The valves are only a few mm larger and not a big deal unless ported.

Another thing is the MPI manifold is a dry flow and will puddle if used on a wet flow setup , the MPI manifold will fit the SPI head but not vice versa unless an adapter is made because the two middle top bolts are higher on the MPI head.

 

[GhostWKD]

Another thing is the MPI manifold is a dry flow and will puddle if used on a wet flow setup , the MPI manifold will fit the SPI head but not vice versa unless an adapter is made because the two middle top bolts are higher on the MPI head.

maybe the punto 75 mpi is dif to sei spi/mpi, i know of someone with a mpi sei who's got a spi supersprint manifold fitted? sorry to throw spanner in works and confuse things more but im confused too

 

[smokeme]

maybe the punto 75 mpi is dif to sei spi/mpi, i know of someone with a mpi sei who's got a spi supersprint manifold fitted? sorry to throw spanner in works and confuse things more but im confused too

I know the sei head is different from the 75 head even though they are both MPI the sei has smaller valves. If anyone has a pic of a sei mpi head we can confirm , i got one of a 75 head just give me a while (i'm uploading my site )

 

[Tricker...]

I didn't realise that . I obviously would have found out soon enough , but better now than later .John

That’s why I wrote it - would be a bad feeling when you get all fitted and ready to start up and not able to go on the road because of the bonnet

Every advice and experience is needed when you do a swap like this

Ok you guys are getting confused here.

The difference in hp between the 60 and 75 is the cam not the port size, the only reason the ports are bigger is so the injectors can spray onto the valves. The valves are only a few mm larger and not a big deal unless ported.

I can only tell you what I know of experience - The cam from Punto 75 is not that big a different from the cam on Punto 55/60. Not saying there are not different at all but it's not much.
If port size doesn't matter then why do I have 95 bhp on my SPI head with a redesigned inlet manifold with bigger ports?
My engine setup is duplicated by another Cinq. owner I my club in DK only he is running with the Punto 75 engine. He has only 86 hp on the exactly same setup...
Off course the port size matters
You are right in the fact that the MPI inlet manifold is a dry and not a wet flow manifold, but the only way to find out if it works is to try it out and test it on the road. If it works it will be great - if not it would be worth the try

 

[smokeme]

That’s why I wrote it - would be a bad feeling when you get all fitted and ready to start up and not able to go on the road because of the bonnet

Every advice and experience is needed when you do a swap like this



I can only tell you what I know of experience - The cam from Punto 75 is not that big a different from the cam on Punto 55/60. Not saying there are not different at all but it's not much.
If port size doesn't matter then why do I have 95 bhp on my SPI head with a redesigned inlet manifold with bigger ports?
My engine setup is duplicated by another Cinq. owner I my club in DK only he is running with the Punto 75 engine. He has only 86 hp on the exactly same setup...
Off course the port size matters
You are right in the fact that the MPI inlet manifold is a dry and not a wet flow manifold, but the only way to find out if it works is to try it out and test it on the road. If it works it will be great - if not it would be worth the try

Simply said the difference in port size between the 60 and 75 heads is very small and only to allow the injectors to spray on the valves, the valves are slightly larger.

The cam on the other hand has a lot more lift

I got the specks here http://smokeme.coconia.net/stock_part_specs.htm

the site is not fully uploaded yet so things are missing but the info is there

The 75 manifold won't wet flow, i've tried it for my 1242 turbo, it would surge when the engine tilted because the plenum fills with gasoline

EDIT:this picture shows the ports on the 75 head (mk1 which has the largest valves) the small difference in the ports can be seen (the smaller roundish part on top of the port)

Since i can't link pics off my site (private folders) you'll have to go here and look at the head pics http://smokeme.coconia.net/picture_gallery.htm it's the picture number 6 (last one second row)

 

[Tricker...]

Simply said the difference in port size between the 60 and 75 heads is very small and only to allow the injectors to spray on the valves, the valves are slightly larger.

The cam on the other hand has a lot more lift

I got the specks here http://smokeme.coconia.net/stock_part_specs.htm

the site is not fully uploaded yet so things are missing but the info is there

The 75 manifold won't wet flow, i've tried it for my 1242 turbo, it would surge when the engine tilted because the plenum fills with gasoline

EDIT:this picture shows the ports on the 75 head (mk1 which has the largest valves) the small difference in the ports can be seen (the smaller roundish part on top of the port)

Since i can't link pics off my site (private folders) you'll have to go here and look at the head pics http://smokeme.coconia.net/picture_gallery.htm it's the picture number 6 (last one second row)

I didn't know the plenum fills up with gasoline when fitting a SPI on a MPI manifold.
I don't know the specks. on the original cam. I can see at your website that the Punto 75 cam is a bit more hot than the Ceonto cam. Not much but it's there. Do you know how much bigger the lift on the Punto 75 cam is?
I can only say that my experience with the Punto 75 cam in the Cento engine is that different before/after is very small.

I respekt your experience with the MPI manifold + SPI injection.

 

[smokeme]

I have the lift info but can't seem to find it which is why i didn't place it on the site

best method in my opinion is to use the 75 head (mk1) and then fab a manifold to use the SPI setup, it should be cheap to make for someone with a welder , that way the clearance issues would also be avoided

 

[minijohn]

A bit more info .
Comparing my MK1 Punto 75 head to my MK2 Punto 60 head (both mpi) , the valves are the same size , but the 75 inlet ports are much bigger - so that's the one I'll use !!

Also , the 75 cam has visibly different cam timing - you can tell the cam lobes are in different positions when compared to the "60" cam .

Finally , the valve lift of the 75 cam is about 3mm more than the 60 cam

John

 

[Tricker...]

best method in my opinion is to use the 75 head (mk1) and then fab a manifold to use the SPI setup, it should be cheap to make for someone with a welder , that way the clearance issues would also be avoided

It is a cheap job to make a manifold, but damn it takes alot of hours to do it :yuck:
I know cause I did it my self

Finally , the valve lift of the 75 cam is about 3mm more than the 60 cam

John

That much

I didn't realize that... seems odd theres not bigger different in power gain when fitted .

 

[smokeme]

It is a cheap job to make a manifold, but damn it takes alot of hours to do it :yuck:
I know cause I did it my self





That much

I didn't realize that... seems odd theres not bigger different in power gain when fitted .

The only reason we don't see more gains with the extra lift is because it's no longer the choking point. You'll experience the most gains with a larger tb and exhaust then the stock

 

[TurboCinqy1250]

Are the exhaust ports and valves the same as the punto 60 head?

And does the exhaustmanifold fit straight or not.

The reason for this Question is that I need less restriction on my exhaust valves/ports and that's why I'm thinking to place a Punto 75 head with Intake manifold.
And will use the MPI injectors for turbo fueling and the SPI for partload running. (got a extra unit to control 6x16 Ohm injectors SMT-6)
(will search for a solution to get no full puddle) and place a 40mm TB on it.

If the exhaust manifold is difference to then I fabrique a Custom manifold from angle tubes.

And last but not least: Is the are possibility to get bigger exhaust valves in it or isn't there enough space. If possible just as big as the inlet valves. (Turbo setup)

 

[Oldschool]

No.

 

[HP]

75 head in the garage has 27mm exhaust and 31mm intake valves.

Anyone got a handy 1108 head to compare?

 

[TurboCinqy1250]

Exhaust 27.2 / 27.5

Intake 31.2 - 31.5 So they are simular.