DOHC 2.0 Conversion; What Do You Think?

Head is the Croma style head, reversed port...so basically tilting engine forward the same as the Croma / Thema. The Fiat Croma / Lancia Thema gearbox would be the one I would use if I was going to turbo charge etc, as it shifts the stater motor to the "rear" side of the engine...away from the hot exhaust / turbo in the Croma application...not many manual Fiat Croma's in Australia and I don't feel like importing a heavy transmission of unknown provenance from overseas...I have plenty of Beta transmissions...internally Beta/Croma/Thema are very similar.

The cam drive end is supported using the Croma/Regata style water pump, the front engine mount bolts to the water pump which is bolted to the block with M8 bolts (not M6 bolts like your 124 etc)...I tilted the engine forward and remade the front mount...top engine stay bar looks just like an X19 one but with a small S bend to the bar and I lengthened it slightly....lower cross member mounts to the bodywork just like stock...I remade this so the mount support allowed the lower mount (an industrial rubber isolation mount) to sit with a slight forward tilt instead of the slight rearward tilt it initially had... went from 10 degrees rear tilt to 10 degrees forward tilt so a 20 degree shift in total. Three engine mounts fit up just like the standard component, rear trans mount on the beta lines up quite nicely with the rear transverse chassis rail so there's a simple mount welded to the body which the stock beta mount bolts to.

130TC trans is harder to find again and a bt of a unique beast...Ritmo 105tc / Regata 100s trans is simple to find, but not as robust...again beta trans are virtually bullet proof whereas the 105tc trans is basically an x19 five speed trans with the same forks/hubs/synchro rings ...so a no brainer to use the lancia beta trans.

You could stand the engine straight up and use a 105TC trans... looking at the bellhousing the internal shift rod bore could possibly be bored all the way thru to allow the linkage rod to exit at the front and not the rear...could possibly allow the stock X19 rod shifter mechanism to be used so there would be no need for shifter mods / pattern reversal / cables etc... but given the 105TC and X19 five speed transmissions inherent differential weakness I don't think it would last well with the power (and especially the torque) that my 2 litre engine makes...so I opted for the heavier and bullet proof beta trans.

Sump is an alloy 130TC aftermarket Alquati sump... oil pump is early Croma / Ritmo 130tc in sump type (later engines used a crank nose driven pump) that has a detachable snout pickup which sits pretty well dead middle of the sump...sump is baffled and pickup modified...no oiling problems when it was tilting rearwards...haven't driven the vehicle yet with the re engineered pickup and 10 degree forward tilt (waiting to find the time to paint the car)

I use a 1978 beta engine block, licensing laws in Western Australia require that with engine swaps the emissions requirements for the vehicle need to match the engine used...i.e. if I used a 1986 Croma block/engine complete I would need to meet 1986 emissions requirements (unleaded filler and cat conv) but if I use an engine bock from the same year of manufacture as the car, then the emissions requirements don't change... hence the late head on an early block build.

SteveC
 
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I like the way this is headed.

I think now my bodywork is mostly complete, the next long term project (after the dash) should be a more powerful engine. I like the idea of keeping it Fiat, and DOHC. If I do go this route, I would feel building a proper Dallara wing would be appropriate :)

The basic parts are the (what years, if I'm searching?) Lancia Beta block, 86 - Chroma head, and Beta trans if I'm reading the above posts correctly? What source for cams? What axles?

Is there an overall parts list somewhere?

"rear trans mount on the beta lines up quite nicely with the rear transverse chassis rail so there's a simple mount welded to the body which the stock beta mount bolts to."

This project sounds like the prefect rationale to get rid of the stock X1/9 trans mount :D
 
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Thank you Steve, as always a throrough answer while you sift through your memory of a series of build ups that started back in 2004, was redone in 2011 (according to T124 threads) and here we are talking it through again in 2018.

Going with a factory 16v head seems like a easier path to higher horsepower without going to extremes with a 8v head. I suppose there are fewer cams for the 16v Chroma/Thema head as most of those were turbo charged or is this an incorrect assumption?

Greatly appreciate the summation about the transmissions, as I just had my X transmission recently rebuilt by SteveH (its the way it came to me, needing a rebuild), I can appreciate a stout transmission. So in your mind a Beta 5 speed would be as good as a Scorpion transmission in regards to getting to a shifting solution? The Beta likely going to a cable solution versus trying to get to a lever fulcrum etc solution on the Scorpion one.

I note when looking at cars like the 130TC that they use a reverse flow head but the return flow of coolant comes from the old position with a cross pipe to the back of the engine where the later 8 and 16v units have the rear outlet. Does this pose a problem relative to the earlier block in terms of how flow comes up from the block to the head or is this just a matter of where the flow goes and one end or the other ends up a bit hotter no matter how you look at it? (This relates to the ongoing argument that 3 and 4 end up hotter due to the heater outlet pipe flow being intermittent due to season).

In any case, it would be of value to have a list of the optimal parts for this conversion as Hussein asks (clearly not your responsibility) and your input would be extremely valuable.

Thank you

Karl
 
Some photos and parts lists from what I presume was the original build of the car from 2004 and then some updates as found in the thread Hasbro (thanks) found on the T124 thread. https://t124.com/forum/forum/fiat-fans/fiat-fans-aa/871-my-x1-9-twin-cam-conversion

A partial list of parts from that thread (updated with corrections and additions from Steve’s post below):

2.0 Lancia Beta block (following block data from here: http://www.villevieri.com/tc/tclist.htm plenty of other info of interest there)
828B1.000...................1995................(->78)......- 2000/Trevi/Coupe 2000
(79->)
828B1.0405..................1995................87..............- California-model
134AS.000...................1995................120.............- Montecarlo EU
828B4.000...................1995................122.............- F.I. (fuel injection)
828B4.0405..................1995................108 / 106.......- F.I, California-model

8v reverse flow head 8valve reversed cylinder head, two oil up holes, very late combustion chamber design, 43.5 intake / 36.5 exhaust valve sizes, cast in number 7676150

16v Turbo head (preferred) the head to look for has the casting number 7669070, and looks like this. Turbo and NA heads are the same head, but with a different exhaust valve (material not size) different valve guide and stem seal (again material not size)

Croma/Tipo 16v VIS reverse port pistons

Late style bolt only rods, much stronger rod, use ARP bolts which are available

Reverse flow camboxes 8v Integrale or late Croma/Thema turbo head) as these have only TWO central oil up holes and the feed to the front/rear cam journals is routed internally thru the cambox, use appropriate gaskets


Beta transmission (Scorpion transmission alternatively if available)

2 short X axles to work with the Lancia axle extension

Scorpion shift linkage if possible

(Fiat Chroma/Thema transmission alternatively if one could be sourced)



Regata 100s water pump-must

130TC oil pump-must



Alloy sump with oil temp sensor originally designed for a 130TC

A Scorpion sump would be most ideal

Stock steel Croma/Thema sump

Alternatively a standard 2.0l 124 sump could be used with modifications, particularly the ‘hammerhead’ mod to add volume and clearance for the reverse flow exhaust coming off the front.


Chassis mods:

As I said the bodywork only needed a small amount cut out to clear the transmission casing, from the left chassis rail, right about where the standard flex brake line mount is inside the wheel arch. I’ve had to move this bracket also, otherwise the brake rubber line will rub on the gearbox end casing. Also the alloy of the gearbox casing needs to be sculpted in a few places to provide a little extra clearance. You have to cut the body or the engine just won’t sit in the right place. I simply plated every thing up very neatly, making it all look very standard with lips in the right places. I also added some plating to the upper surfaces of the chassis-rail. I also gusseted it up where it connects to the forward engine bay transverse chassis member.

You do however, need to give a bit more clearance than the standard rear control arm will give to the gearbox. This involved cutting away, mostly from the upper part, sufficient material. I then boxed the arm, enclosing the open side. This should give it sufficient strength, but to be sure I added the amount I had cut from the inside edges of the arm back onto the outside of the arm as well.
There is obviously more in that thread but these are the initial highlights gleaned.

C61BB710-1482-4B7F-9538-6225335BC036.jpeg
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Wow those are old pictures... I had lost those in a computer hard drive failure and didn't realise they were still somewhere in cyberspace, thanks for finding them.

Axles = 2 x X19 short side axles and CV joints... about as simple as you can get. The Lancia Beta uses a short fixed axle and support on the RHS of the car, get these exactly equidistant from the drive flanges on the rear hubs and you have the engine and trans assembly in the correct place in the left/right plane...any more than a couple of mm out and which ever ends up the shorter side will have very slight CV binding issues in the range of travel, so pretty important to get this correct. Same with the position of the engine fore/aft. I felt it was quite important to get the drive flanges precisely in line when the car is at ride height...when I reversed the tilt of the engine it required a little finessing to the engine positioning, so it's now a little different to the pics as shown (to keep the starter and my oil filter adaptor from clashing with the bodywork mostly) the crank centreline moved back a touch (it moved back by maybe 6mm - 1/4 inch which I felt was acceptable for the CV alignment)

Any year Lancia Beta engine and trans could be used as a donor... ideally the scorpion shift linkage entire assembly and clutch lever arm if you don't feel like doing a lot of metal fabrication. It doesn't need to be a scorpion drive train you start with a regular run of the mill rusty beta could be an engine donor.

I didn't have access to a scorpion sump or oil pump and the 130tc / 105tc alloy sump came up on ebay quite cheap... you could use the stock steel Croma/Thema or even fabricate something using a regular "front well" 124 style 2 litre sump as a starting point, which might even work better as it could give a little more exhaust clearance room under the sump at the rear of the engine (the exhaust needs to pass under the engine quite close to the cross-member in my case) A picture of a similar sump to the sump I used that I found online.
abarth alloy sump.jpg



When I chose to change the head to a later reverse flow style, I didn't have access to a 16 valve late Fiat head... if I was to do the conversion again I think a 16v head would be nice as it really is worth about 20% more power/torque... I've bought a couple of NOS 16v heads since, but the expense might put some people off as the head was close to double the late 8v style, and then the cams get really pricey for NA aftermarket ones (twice as many lobes means about twice the price) add in the camshaft oil spray bars, custom manifolding etc and it would be a chunk more $$.

Just on a side note Karl, the VIS Thema head is the 16 valve head you DON'T want for a NA applcation, as it has considerably smaller ports and intake valves than the "regular NA" and turbo heads.

regata 100s water pump makes supporting the cam drive end of the motor quite a simple job, so yes that's the one I would definitely always use... always available ex ebay as it fits many pedestrian fiat/lancia models.

Hussien, beta rear trans mount... is in ADDITION to the lower engine mount... as a Beta uses four engine mounts to support it in a regular Beta, it simply assist the top engine stay bar to stop the engine moving / rocking back and forth under torque.

Reverse flow camboxes and covers... there are a few different types... same with reverse flow heads... basically a difference during production in the oiling to the camshafts. A regular 8 vlve twin cam uses 6 oil up holes to feed the cam journals. In performance applications it's usual practice to reduce the size of the holes to restrict the flow of oil upwards... the cams are over oiled in early engines and there is benefit in keeping more oil heading to the main and big end bearings. The first "reversed' heads still had 6 oil up holes... I chose to use the later production (actually a 8v Integrale and late Croma / thema turbo head) as this only has TWO central oil up holes and the feed to the front/rear cam journals is routed internally thru the cambox..so you need to use the correct head gasket/cambox gasket and camboxes to suit the reversed head being used... a potential trap for those unfamiliar with the engines.

130TC oil pump...also fit a few other fiat models which I cant recall offhand... again available in europe on ebay, they are not plentiful and cheap like 1800 124 oil pumps though, but it's a one off purchase and keeps the engine alive...I've seen / heard of a few twin cam conversions spin the big end on number 1 due to oil starvation... most of these used the beta pump... as I said I didn't have access to the monte/scorpion sump and pump (both of which can be pricey and hard to find) so the 130TC pump was my solution and worked ... no oiling issues. heres a pic of the oil pump I used that I found online.

$(KGrHqF,!iEE1K8q0fFRBNZToCRhKQ~~_12.jpg


I now exclusively use the late style bolt only rods in all twin cams engines that I build... much much stronger rod, ARP bolts are readily available, and they are relatively cheap to find new/ used ... forged aftermarket lancia Integrale rods are available these days too.. 15 years ago when I started this build they weren't so cheap...so I would be including these on the build parts list too.
bolt only conrods 16v.jpg
parts arrivals 010.jpg


SteveC
 
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? is this transmission swap something that could be done to the original motor as well? (have 8 x1/9's currently (three running/driving) and each one has a week transmission) think often about having them rebuilt but at 2k per unit and still have a design that is prone to fail I am not overly excited about going that route. (would love to do the k20) but lot's of $$ and time that I don't have either of right now.
 
When I chose to change the head to a later reverse flow style, I didn't have access to a 16 valve late Fiat head... if I was to do the conversion again I think a 16v head would be nice as it really is worth about 20% more power/torque... I've bought a couple of NOS 16v heads since, but the expense might put some people off as the head was close to double the late 8v style, and then the cams get really pricey for NA aftermarket ones (twice as many lobes means about twice the price) add in the camshaft oil spray bars, custom manifolding etc and it would be a chunk more $$.

Just on a side note Karl, the VIS Thema head is the 16 valve head you DON'T want for a NA applcation, as it has considerably smaller ports and intake valves than the "regular NA" and turbo heads.

Reverse flow camboxes and covers... there are a few different types... same with reverse flow heads... basically a difference during production in the oiling to the camshafts. A regular 8 vlve twin cam uses 6 oil up holes to feed the cam journals. In performance applications it's usual practice to reduce the size of the holes to restrict the flow of oil upwards... the cams are over oiled in early engines and there is benefit in keeping more oil heading to the main and big end bearings. The first "reversed' heads still had 6 oil up holes... I chose to use the later production (actually a 8v Integrale and late Croma / thema turbo head) as this only has TWO central oil up holes and the feed to the front/rear cam journals is routed internally thru the cambox..so you need to use the correct head gasket/cambox gasket and camboxes to suit the reversed head being used... a potential trap for those unfamiliar with the engines.

SteveC

Thanks for all the details.

I'm confused as to which 16V head, cams and camboxes specifically work for the NA EFI setup. Also you said the exhaust passes under the motor - isn't the point of getting a reverse flow to have the intake on the firewall side I'm confused here also :D .
 
Thanks for all the details.

I'm confused as to which 16V head, cams and camboxes specifically work for the NA EFI setup. Also you said the exhaust passes under the motor - isn't the point of getting a reverse flow to have the intake on the firewall side I'm confused here also :D .

(Edited for content based on Steve’s note following)

So nearly all of these parts were never sold here. The reverse flow head puts the intake on the rear firewall side as is in the SOHC engines but being a crossflow head the exhaust is on the front firewall side. This is the opposite of the US models of the 124, 125 and 132 engines we have gotten here where the intake would be on the front firewall side and the exhaust to the rear. Additionally the 16v and later 8v heads moved the coolant neck from the belt end of the motor to the rear of the head which eased the plumbing and cleaned up the top of the engine a bit putting things where they are needed anyway in a transverse application. Particularly when it gets added to a mid engined car :)

If you could get whatever you want it would seem like buying a NA 16v Croma engine with transmission and then added a turbo 16v head would be the bees knees.


16v NA heads, turbo would look similar just marginally different valves (material)
(Image to come later, original image as from the Fiat Pratola Serra modular engine series)


With the rearward tilt he originally had space for manifolds and carbs but was quite limited. Once he tilted it forward going to a reverse flow head allowed the intakes to move to the rear and the exhaust to go out the front and therefor it needs to run under the motor. With a wide oil pan, the only place to run the exhaust is where the engine crossmember is without having it be the lowest object on the car which is never a good arrangement.

The best head is the 16v turbo head due to the material of the valves and of course their multiplicity which ensures good breathing and therefor the power we all desire. Happily there are normally aspirated versions of the 16v motor so there are cams which work for NA, turbo cams are not the best arrangement for a NA engine as you know from playing with your bricks. The NA 16v pistons would also be needed versus the turbo ones for compression.

That said, the 8v reverse flow heads would also be a good option for all the the packaging needs covered up above just less desirable from a power and overall packaging standpoint.

16v reversed flow rear coolant port, lower down on end of head versus on topView attachment 14457


Standard flow early 8v head as used in Ritmo 130TC, this engine is nearly bolt upright.
E8D4B7C8-8F69-4F46-B0A0-EC64AD0115C1.jpeg



Late reverse flow 8v head with rear coolant port, this engine is tilted forward
16v looks similar
88DFE817-2B73-48B4-99D5-7B684A19FBA1.jpeg


Lots of choices in the parts bin. Perhaps a trip to the EU for a week to find a couple of cars that won’t pass inspection that you could break to get the nasty bits you desire... :)
 

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Reverse flow early 8v head as used in Ritmo 130TC, this engine is nearly bolt upright.
View attachment 14458

close... but that head is a "regular flow" 8 valve head, basically the same as a 124 spyder... flows intake from the right (when viewing the engine from the front) ... this puts the intake at the front firewall in an X19

16v NA heads, turbo would look similar just marginally different valves.
View attachment 14456

This is actually a different 16 valve head... suits a different engine architecture (like in a Fiat Barchetta) ... gets confusing ... but there are three distinctly different 16v engines (well four if you count the 500 type)

Bravo/brava style 16 valve...this engine is the "torque" designation and architecture is based on the Lampredi SOHC engine (ie bore spacing, and 8 out of the ten head bolt holes)

Thema/Croma/ Delta 16 valve, based on the DOHC Lampredi engine architecture... fits the early 8 valve block.

Barchetta/ Fiat coupe... based on a "Modular" design... i.e. the 20valve 5 cylinder engine and the 16v four cylinder engine ... does not fit the Lampredi sohc or dohc blocks as it's a totall different engine.

Fiat 500 style (fire) engine which comes as a 8 valve and 16 valve...

if you want to go 16 valve, the head to look for has the casting number 7669070, and looks like this. Turbo and NA heads are the same head, but with a different exhaust valve (material not size) different valve guide and stem seal (again material not size)
dohc 7669070b.jpg

dohc 7669070a.jpg

dohc 7669070c.jpg



SteveC
 
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Thanks. Ugh, does it ever end? The education of Karl.

I will go back and correct this evening.

I should have caught the Ritmo one as you can see the carbs right there in front. It was late...

The others lack of knowledge and mislabeled elements on the internet
 
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and to be complete and thorough, this is the 8valve reversed cylinder head that I'm using... two oil up holes, very late combustion chamber design, 43.5 intake / 36.5 exhaust valve sizes, cast in number 7676150

dohc 7676150a.jpg

dohc 7676150b.jpg

dohc 7676150c.jpg

the only oilways up to the cams are at the belt drive end of the motor. ... no oilway in the central position, the "rear" (water outlet/transmission end) simply uses this oilway position to insert some locating dowels.

and for those that are not so familiar with the "regular" flow dohc... here's a pic oriented the same as the one just above, but note the cambox base layout is "reversed" and the drive end is at the water outlet end... also note the six oil up holes.
dohc 4326318c.jpg


SteveC
 
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Steve, what is your 8k rpm motor used for? Street, track?

I spoke to Pete about fuel injection. Anyone care to comment re. it's viability?

Would an Accusump help with running the exhaust? Could it enhance engine placement or does the transaxle completely determine placement?
 
if you want to go 16 valve, the head to look for has the casting number 7669070, and looks like this.

That is really interesting Steve. When I checked quickly on eBay they listed a couple of these, both for an Alfa Romeo 155 2.0 Turbo 16v Q4. Typically the 4 cylinder 155s (and 156s) used the "twin spark" engine that was essentially the progression of the Busso Alfa twin cam (used since 1954 in the Giulietta, Giulia, etc.).

It is unusual that the 155 could accommodate both the 4 cylinder Alfa DOHC (Busso) and the 4 cylinder Fiat DOHC (Lampredi).

Cheers,
Dom.
 
The Alfa 155 is the same platform as the first generation Lancia Dedra and the Fiat Tipo. I once put a twin spark engine and box into a Dedra. The Busso twin spark engine sits a little more upright than the Lampredi and all that was needed was the correct 155 mounting brackets to the car body to correct the angle. The 155 Q4 is I believe a Delta 4WD set up in the 155 body, hence it uses the Lampredi engine.
 
Steve, what is your 8k rpm motor used for? Street, track?

I spoke to Pete about fuel injection. Anyone care to comment re. it's viability?

Would an Accusump help with running the exhaust? Could it enhance engine placement or does the transaxle completely determine placement?

Personally I prefer fuel injection as it can make for a much more reliable and consistent vehicle.

Once sorted.

This is the crux of the matter, building the injection system and getting it to work properly.

You could use the Lancia Beta injection setup, which a number of Scorpion owners have gone with has been fitted to the much larger Scorpion engine compartment. Don’t know how that would do in the X space.

It gets down to the room actually available and how comfortable you are with the one system or the other and how much you can do.

I am trying to sort in my mind how an Accusump would resolve the issues of the sump and the exhaust?

The Lancia transaxle and the X suspension uprights in combination with the X short axles drive the placement of the engine.

One could imagine the exhaust being routed more to the right side but in all likelihood the suspension and its pickup points would drive the exhaust to the middle or more to the middle versus being able to be justified to the right side. Some shots of the underside and relationship of parts would certainly help. I would bet there are some images on the T124 forum could be found.

Karl
 
Would an Accusump help with running the exhaust? Could it enhance engine placement or does the transaxle completely determine placement?

Barry, just so there's no confusion about what the Accusump is, it has nothing to do with the oil pan. It's a device that fits inline in the oil cooler/filter circuit. It is charged with compressed air and holds a reservoir of oil. When oil pressure drops below a certain level then a valve opens which uses the compressed air to force the oil in the reservoir into the engine. This can save the engine from oil starvation in a situation like extremely hard cornering. Engine oil pressure refills it when oil pressure returns to normal. It also provides full oil pressure as soon as the ignition is turned on, so it is also a pre-lube on start-up.

Pete
 
So, what internet sources does one look at to find such parts? I'm not having any luck finding 16V heads for Delta/Chroma, only 8V :(

Haven't even started looking for blocks or misc parts.

The LH2.4 will be more than sufficient to run the 16V setup in my case.
 
So, what internet sources does one look at to find such parts? I'm not having any luck finding 16V heads for Delta/Chroma, only 8V :(

Haven't even started looking for blocks or misc parts.

The LH2.4 will be more than sufficient to run the 16V setup in my case.

order from europe lancia thema engine !
 
So, what internet sources does one look at to find such parts? I'm not having any luck finding 16V heads for Delta/Chroma, only 8V :(

Haven't even started looking for blocks or misc parts.

The LH2.4 will be more than sufficient to run the 16V setup in my case.

There are two on eBay right now for the head anyway. No cams but do have all the valves.
 
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