New 8V block for 16V head use- How to fit them together?

[dfom]

Hy everybody,

I´m writting to show my new old stock Fiat TC engine. I´ve bought this from Fiat last week, Fiat has put this engine on sale, i think they are freeing some space at their factory.

About this engine:

This block is a 2l TC used in Brazil for our Tempra Turbo version. It has an CR of 8:1 with the 8V head. It has pistons with a bowl in the centre. And a tick land between rings. I´ve also bought four C class pistons for this engine (it came with four A class piston).

I intend to use this engine with an 16V head, and i need some advice on how to change it for the task (i´ve read somewere that i would need to block two oil galerries, but not sure about it )

Some pictures:









Bye

[Guy Croft]

I've done quite a few 16v conversions, never had a leak when fitting the 16v head without blanking off oilways not used, but after a number of reports from private individuals doing same, I now do.

Photo shows which ones, you can thread the center and rear oil galleries (yellow boxes) with M8 grubscrews very easil. When I thread out I attach a vacuum device to the oil circuit to catch as much metal debris as possible and of course it is vital to unplug the main oil galleries to clean it after, otherwise debris from threading is going to go straight in the bearings. Make sure you put the rear right plug in deep enough to allow the gasket locating dowel to be fitted.

I use the OE Tipo 16v head gasket and bolts.

Hope this helps in the first instance,

GC

[dfom]

GC,

Thanks a lot. I´ll buy an 16V head soon, as the project evolve i´ll keep my post updated.
My goal is to fit an Eaton M45 Mercedes supercharger into my Tempra.

Thanks again.
Bye

Daniel Melo - Brazil

[Guy Croft]

I'm particularly interested in belt drives with these conversions.

With the early block (as shown in my photo) and its associated crankshaft, I use the wide 131 type crank nose toothed pulley ('driving gear' in Fiat parts list) with block mounted 131 tensioner and GC wide adjustable pulleys, this takes my 1" wide 148 tooth belt and is a proven setup.

With your unit I don't know what type of belt drive pulley it has on the crank, although I expect it is the short one similar to Tip and Integrale. That short pulley will not accept 1" belt and I would not want to drive a 16v setup off a 3/4" wide trapezoidal (rectangular style) belt - I'd be very concerned about the possibility of the belt 'jumping' under the high load imposed on it. However, Fiat's later generation belt (as used on Integrale and Tipo, Coupe 16v) is a proven design and will accept high rpm on that setup comfortably.

There are several types of late type short nose pulley available, one with integral key and one with separate key (the key locks into the crank nose to drive the pulley). The basic design (in terms of length, OD, ID) is used on all the later TC 8v and 16v models, but they differ in that the 8v ones like yours use a trapezoidal toothform (Integrale 8V, Delta 1600 ie) and the 16v using the unique Fiat type toothform (don't know the technical name, it's not HTD..). Given that the best pulley & belt to use on that motor on a 16v conversion is the later OE Fiat setup, it follows that the cam pulleys should be Integrale type which are aval from Kent and Piper, and the tensioner would be the one bolted to the head as on the Integrale. I have never had 8v and 16v pulleys on the bench on the same day - but from memory they seem identical apart from the toothform..

Do you have the pulley for your Tempra block? I'd like to see a photo if you have one. I figure it's trapeziodal, so we need to do investigate the availability of an Integrale type and hope it will fit your crank. So far I have been unable to get one from Fiat, or learn anything useful - so if anyone knows about the interchangeablity of the 8v and 16v late crank nose pulleys or a part number I'd very much like to know.

GC

[Guy Croft]

By the way, in case you do not know, to fit class C pistons in class A bores you will need to hone the bores bigger to give required running clearance.

GC

[tmvolumex]

Interesting looking breather / oil separator on your new engine block. It looks to have significantly larger flow capacity compared with the units on a normally aspirated engine. This makes sense as a turbo engine will have more blowby. Do you have any additional details or photos of this separator?

[dfom]

Interesting looking breather / oil separator on your new engine block. It looks to have significantly larger flow capacity compared with the units on a normally aspirated engine. This makes sense as a turbo engine will have more blowby. Do you have any additional details or photos of this separator?

About the Breather

Indeed, this breather is larger than the N/A engine version. After gas pass thru the breather it reaches another device called by Fiat as "Separator"

This device is a simple box with an wall inside. Something like this drawing shows.

Brazilian Tempra Turbo Separator internals

Separador.JPG (15.71 KiB) Viewed 19808 times

As oil is unable to go upside, it goes down to sump.
In the sump there is a tube for connecting the hose that comes from the Separator unit.


About the Belts


Here 8V engine uses belts with this specs:

Width - 18mm
Lenght - 1351mm
Height - 4,25 mm
Numb. teeth - 142
Tooth to tooth distance - 9,525mm
Tooth height - 1,90mm

Goodyear code - 532LH071
Dayco Code - 142s180
Gates code - 41142x18

16V engine use belts with this specs:


Width - 18mm
Lenght - 1384mm
Height - 5,40 mm
Numb. teeth - 173
Tooth to tooth distance - 8mm
Tooth height - 3,08mm

Goodyear code - 173HP8180
Dayco Code - 173SHPN180H

So they are different tooth profile.

18mm is 0.71", almost 3/4". So our belts are not the wide version.
I was wondering about belt "enlargement" yesterday. Here Marea 2.4 5 cilinders use 24mm (1") belts with the same tooth profile for the 16V 2L, but with only 168 teeth, 16V belt minus five teeth.

I don´t know if my crank pulley would be large enough to fit this Marea belt, nor if i have enough clearance for tensioner (as it has minus 5 teeth)
Just by opening the belt protective cover i will be able to check it. This weekend i´ll do this.
Case it doesn´t fit i´ll look after a solution for the belt problem.

About the tooth jump problem, that happens with the 3/4" belt, it´s worth mentioning that here in Brazil the first two year producion 16V engines suffered from this problem.
Fiat has made a change in the belt system by inserting an extra bearing along the belt longer lenght side (the side oposite to the tensioner).
At the middle of the lenght between the crank and cam pulleys.

This bearing only touchs the back of the belt. It avoids the increased vibration of the belt along this side. Fiat said this solved the problem (not really)
For the early 16V Fiat produced an adptation kit that allows an easy fit of the extra bearing.

Dispite Fiat effort in reducing belt failure, our 16V are known by been an belt eater, i guess because of the narrow belt used.


About the pistons

This new engine block came with four A class pistons alreary mounted. The four C class pistons are backup ones, case a i make some mistake (hope never to use them)


Really thanks for the help and forgive-me for any typos (i am doing my best)

Bye

[Guy Croft]

Daniel, hi

As far as I know ('AFAIK') all Integrale/Thema/Tipo/Coupe 16v 2 liter type units (ie: the models with those annoying balance shafts) that I have seen had a back-tensioner from 'day one' from Fiat/Lancia (as shown below, yellow box), collocated with the balance shaft pulley. I am not aware of the balance-shaft type engines ever being produced in Europe without it.
Again, AFAIK 1800 units 8v and 16v (which carried the trapezoidal tooth form belt) had no back tensioner and just a long run from ex cam-crank.

Can you be more specific as to which models you know of (cubic capacity and 8v or 16v) were given this retro-fit extra tensioner kit please? I've never heard of it, which is not by way of saying it didn't exist, by the way! Photographic evidence would be great.

GC

[dfom]

Guy,

I´ve removed all my belts yesterday and made some measurements. Before showing the data i will aswer your question.

TCs in Brazil

Our TC engines are all 2L with 8 or 16 valve head. Balance shafts are not present (except for Tipo sedicivalvole) (i guess Fiat strategy to reduce costs).
So, compared to the picture you´ve shown our extra tensioner is placed right there, in fact i think a little bit higher. (I will take a picture from the belt and tensioners)

Belt´s tooth is called by goodyear "H8P" (not sure if this is the trapezoidal one you mention).

Probably Fiat realized that without the back tensioner (provided by the shafts) belt´s tooth jump was a major problem, so they modified brazilian´s TC original design.

About my belt enlargement issue

I´ve collected this measurement:

1 - Cam pulleys - Width 24,75 mm
2 - Crank pulley - width 19,5 mm

So, as seen by the data presented, i´ll need a larger Crank pulley. I´m in doubt if also a larger cam pulley is needed. Would the 24,75mm pulley fit an 24mm belt without problems? Or must i provide more clearance?

I´ve also concluded that a tensioner repositining is a must for the shorter Marea belt.
A last question: Have you any idea if Fiat 2.0 20v ou 2.4 20v crank pulleys fit over TC crank?

Bye, thanks for the adivices.

Daniel Melo - Brazil

[Guy Croft]

Dan, you're losing me with all this data.


Members! I don't exactly have much time to read, a picture, as we say, is worth a thousand words, which is one reason my posts are generously illustrated.


Our TC engines are all 2L with 8 or 16 valve head. Balance shafts are not present. Can you name the models please? All the 16v 2 liter engines in UK have balance shafts. You have some 16v 2 liter with none? Which one, photo please.

More on belt choice later.

GC

[dfom]

Guy,

I´ve arrived from office and taken some pictures. I´ve tried to take the best shots possible, but as the engine is inside bay and pictures are not the best.

Tempra 16v Brazil -

P4070157.JPG (101.71 KiB) Viewed 19585 times

Tempra 16V Brazil - Tensioner (left) - Auxliary bearing (right )

P4070159.JPG (87.34 KiB) Viewed 19577 times

This picture shows the placement of the so called "auxiliar bearing".
This engine was built in 1998. Until 1994 16V engines did not have this bearing. So the straight exaust cam to crank pulley path was used.
Later Fiat changed it by adding this bearing and releasing a KIT for mounting the bearing in early block that didn´t come with it.

The auxiliar bearing is placed at the engine block, tensioner at the head.

Some pictures from an old auxiliar bearing.

P4070188.JPG (30.04 KiB) Viewed 19541 times

P4070189.JPG (28.88 KiB) Viewed 19545 times

P4070190.JPG (40.73 KiB) Viewed 19542 times

P4070191.JPG (34.91 KiB) Viewed 19544 times

Tempra 16V Brazil - Exaust pipes - No balance shafts.

P4070161.JPG (85.37 KiB) Viewed 19570 times

Tempra 16V Brazil - Exaust Cam Pulley and OE belt.

P4070167.JPG (80.56 KiB) Viewed 19567 times

Tempra 16V Brazil - intake and exaust cam pulleys and OE belt.

P4070166.JPG (94.89 KiB) Viewed 19561 times

This picture shows how small is the OE belt compared with the pulleys.
Pulleys are 24,75 mm and belt only 18mm. I am not sure if there is enough space for the 24mm belt with these OE pulleys.

Bye,
Daniel Melo - Brazil.

[Guy Croft]

Well done, some good material in those photos.

Is that 16v Tempra with no balance shafts a 2liter?

GC

[dfom]

Guy,

Yes. This is 16V 2L without balance shafts and with the extra "auxiliar" bearing along the exaust-crank side of belt

Daniel Melo - Brazil

[Guy Croft]

I think that is 'news'. Am I right?

I have not seen any late type 16v unit without balance shafts at 2 liter capacity in Europe.


GC

[dfom]

Guy,

Indeed! I´m suprised by the fact that all european 16V 2l have balance shafts.

Here in Brazil only two 2L 16V FIATs do have balance shafts: tipo sedicivalvole and coupe. Both imported from italy.
Others were built in Brazil. I don´t know if the engine code at brazilian Fiat catalog would mean anything for you, but they are as follow:

1 - Tempra 2l 16V engine block OE code : 7077995 (with pistons, crank, oil pump)
2 - Tempra 2l 16V engine block OE code: 50005933 --->Late replaced by ---> 50005934 (engine block only)


Those code begining with "5000..." ,by my previous experience with other parts, are from itens brought directly from europe, but not 100% sure about that, may also have been cast in Argentina.

Sorry about the extra data and numbers in this post, but i think it would be nice to register those engine diferences for others to read.
I think those information may be valuable for someone in future. (at least for people from Brazil and Argentina)

Bye.

Daniel Melo - Brazil