Repairs and upgrades to a 1585 TC

[124CC]

Soon after I got my 124 Sport Coupe CC on the road, I noticed that the performance was way lower than what everybody described so I decided to take it to my workshop.

After removing the cylinder head we found out the following.

The engine is a 1585cc 132 engine and not the original 1592cc one.
Exhaust valves damaged (therefore much lower compression)
A very thick 1.9 millimeter gasket (nobony knows why, as the valves would not touch the pistons in any case)
Low compression pistons.
Cylinder head lowered.
Cylinders in excellent condition and standrad size.

The engine produces 98hp according to specs I found on the internet and I would like a little bit more than this so I was thinking about the following:

I have a set of higher compression pistons from a Lancia Beta which should increase the compression ratio to the range of 9.8:1
Twin Weber 40 IDF's
I also have a cylinder head from a 1608 engine with big intake valves which needs some minor modifications to the water passages according to Guy Croft, but I am not sure if this would actually make an improvement.
The cylinder head currently installed on the engine is a standrad 1585,1592,1995 head which has been lowered and had minor intake port polishing.

Opinions please?






 

[jasonh131]

Head lowered , meaning its been skimmed to get rid of the warping off the surface .
  and the valve need a good seal on any head so replace damaged one's and chech your 1608 head

[124CC]

I think mine was skimmed not only to get rid of warping but in an effort to increase the compression ratio.
Would it make a difference if the 1608 head would be installed? (which has the bigger intake valves etc)

The pistons on the left are like the ones currently installed on the engine and the ones on the right are the ones I intend to install for the compression ratio to be increased.

[131 Lover]

Hi!
shouldn't the 124 sport coupe cc 73-75 have the 1756 engine with the 9,8-1 in comp?
Alf

[124CC]

Mine is the 1600 version and should have the 1592cc engine but unfortunatelly it doesn't...
The cylinders of the 1585cc engine current;y installed on the car are in excellent condition so I decided to keep it and upgrade it.

[131 Lover]

Hi!
The 1585 we have, have pistons with 8mm dome as standard to reach 9,35-1 in komp,the one you have looks like the 5,2mm dome for the 1756 with 9,8-1 standard komp.
Don't you have any regata,Ritmo105,lancia Prisma head, who has 43,5mm inlet valves,and are standard on these models.

Alf

[124CC]

I found a head with number 5936188 with large diameter 43.5 mm valves.
The friend who gave it to me removed it from a 130tc engine, but according to Guy Croft, it comes from a VolumeX.

Any ideas?

[131 Lover]

Hi !
You will need a head from a 1600tc,the 2l have bigger combustionchambers than the 1600, 48cc and the 2l have 54cc, and if its a volumex even bigger I think.

You will lose a lot of comp with a 2l head, if it wasn't so expensive shipping I could supply you with a head and pistons so you had the 43,5mm intake and 9,35-1 in comp!

Alf

[124CC]

Since the bore is the same on both the 1.6lt and 2lt cylinder heads (84mm), should I assume that my 2lt head has slightly bigger height than the 1.6lt one, thus resulting in a bigger combustion chamber?
If this the case, I could take the head to a workshop and lower it to the desired combustion chamber size 
 

[Tas131]

Measure it before you cut it. Easy to CC the chambers.

[131 Lover]

Hi!
When I get time,in between the dipers I can take take some measurements since I have both heads.
But I think they have different chambers just not in height,so don't skim the head so you get valve to piston issues and not alot in gain in comp!

Alf

[124CC]

OK we measured the 130tc head and is is about 52-54 cc as Alf suggested.

With the big dome pistons we installed the compression will be at around 9.35-1.

My standard cylinder head (which has been lowered to the limit) will give compression around 10.0-1.
So the dilemma is, 130tc head with big valves and ports and 9.35-1 comp. or my head with standard valves and ports and around 10.0-1 comp?

[vode131]

I would use the smaller head (ported off course) because 1,6 litre engine does not need big ports of 130tc head. With bigger compression and smaller ports it is more driveable.

Fiat 8v twincam head is actually quite easy head to work with. Here is some pictures from the small port head I ported.
http://vode131.kuvat.fi/#/kuvat/Turismo++Competizione/

Here some porting pictures too. This is from my friends 131 racing engine I did for him. If I do this kind of "street porting" job it takes maybe 6-7 hours.

http://vode131.kuvat.fi/#/kuvat/Sekalaista/131+Racing+moottori/

[124CC]

What about finding a 105 TC head?
It will produce compression around 10-1 and has big valves and ports.
The engine is going to be used for historic racing purposes on my 124 sport coupe CC.

[Tas131]

What cams, carbs, exhaust are you going to use? No point upping the compression if everything else remains standard.