Euro-spec tuning tricks for US Betas

[SubGothius]

In trying to digest this thread re: US vs. Euro specs (http://lancisti.org/forum/viewtopic.php?t=1105) and others into a feasible summary of simple/cheap DIY tuning options for US Beta/Scorpion owners wishing to at least bring their detuned cars nearer to their original non-US/Euro streetable specs, the gist I'm getting goes something like this: Put a 1800 head on a 2000 block for a modest, easy (and easily reversible!) compression boost;
Pick one: Use stock cams but have the dowel hole on the intake cam's US-stock timing gear redrilled with ~6 deg. advance (i.e., have a machine shop drill a new dowel hole ~174 deg. from the stock hole, so you can always return to US spec easily);
OR, just get a hotter intake cam (realzing that the hotter one goes, the peakier and less streetable one gets) only, foregoing the expense and troubles of hotter exhaust cams entirely; Pick one: Convert to FI;
OR, upgrade to a bigger single carb -- at least a 34DAT/DATR/DATRA/DMTR to match non-US stock spec, or get a custom manifold or adapter (to rotate the carb mount by 90 deg.) to allow fitting a single 40DCNF or 38DGAS (or Holley 5200-series if any of these are >34mm and synchronous?)
OR, upgrade to dual carbs (40DCNFs or 40DCOEs or 40IDFs, incl. special manifold, etc.) -- not for the faint of heart nor of skill.Whadaya think, folx?

[cthargiss]

Tye, IMHO power gains from greatest to least:
1) Compression ratio (use european 9.8:1 pistons)
2) Head porting
3) Cams (1608cc cams and sprockets give a good increase and excellent drivability)
4) Exhaust headers and freeflow 2.25in exhaust
5) EFI
6) dual carbs
7) 34 DATRA
Craig

[Will]

Craig's got a lot more hands-on experience than me in this arena, but I'm going to take a different approach:

First off, we are back to the old 1608 argument. There has been an EXCELLENT post elsewhere on this forum quoting exact specs from Pittatore. Read that first.

To correct the Scorpion's lagging intake timing, just swap the gear. You don't need the flange, so you can drop a beta gear on. The timing difference is six degrees CRANK which is equal to 3 degrees cam, in other words if you were to redrill (theoretically) you would want it redrilled 3 degrees counterclockwise relative to the edge of a tooth.
In your example, that would be 183 degrees clockwise.

It's certainly cheaper/easier to do all the below at the same time:
FI conversion
Throttle body
HC pistons
Hot intake cam (since you swap to FI, use the 2L FI head and dizzy, this also lets you use the 10.4 slugs)

And then if you want more power:
Port
Big Valves (nobody mentioned this yet)
Uprated injectors

And then if that's not enough:
Turbo
Rising rate FPR.

Of course, thre are other cheaper ways that have advantages and drawbacks (nitrous, methanol fuels, etc.) The nitrous is only really useful in the 4-6K band unless you go staged injection, and nitromethane can rust out your engine pretty good, in addition to being expensive, so you need to purge the engine w/regular fuel or have some other custom goodies (chrome rings, etc.)

I have tried the nitrous and it works, but no panacea. As far as fuels,I would only run what I can get from a pump, and around here that's ~100oct.

Were I you, I'd go with 2L head FI conversion and hot intake cam, swapping to HC slugs while I had the head off. I'd also fit a 60mm TB.

This leaves the avenue to adapt to turbo and rising FPR later, as the 2L plenum is adaptable easily to a turbo.

It'll be interesting to see how many different views we get on this one.





-Will

[SubGothius]

Thx, fellas -- all very good suggestions. I wanted to keep this within the realm of amateur backyard weekend mechanistry, which is why I opted not to mention HC pistons or other mid-/bottom-end work or stronger medicine. My notion was basically of having a hot top-end to swap freely and relatively easily with a stock top -- one could keep all the stock bits, including manifolds, connected to a stock head, then simply swap that with an 1800 head to boost compression a bit (on a 2L block), along with better manifolds (e.g. at least a stock 4-2-1 to replace my CA 4-1, since I'm not living in CA), bigger carb(s), perhaps ported and built with big valves, etc. Comes time for the smogman or moving to CA, put the old Cali garrote, intact, right back on. ;)

[Will]

In that case I would use a complete 2L FI engine with your 1800 pistons.
And a 60mm throttle body.
That should be smoggable, requires minor mods to the vertical shift linkage, last system I built like that took about 40 hours labor, but I was being more meticulous than necessary. There are pics of the components over in my photo album- the only hard part was making a throttle sector out of an old water jacket inspection plate- this took me about four hours.

Then, you can also bump up to a 40/80 intake and it will PROBABLY STILL be smoggable! Can't say for sure, but the stock FI passes smog easily.
-Will

[Frezer]

... requires minor mods to the vertical shift linkage, ...
-Will
Does that mean that a standard Beta FI intake manifold will not fit straight away?

cheers, Merijn

[Will]

Correct, see here for where the "jog" is added to allow the vertical shift linkage to clear:

http://www.savetheledges.org/test/AVS/images/fi/scorpfi.jpg

[SubGothius]

To correct the Scorpion's lagging intake timing, just swap the gear. You don't need the flange, so you can drop a beta gear on. The timing difference is six degrees CRANK which is equal to 3 degrees cam, in other words if you were to redrill (theoretically) you would want it redrilled 3 degrees counterclockwise relative to the edge of a tooth. In your example, that would be 183 degrees clockwise...
So, the intake-cam retard only applies to Scorpions, not FWD US Betas (particularly my '79 carb'd 2L)? If so, then nevermind about the redrilling the intake camwheel dowel to re-advance the intake timing on a FWD Beta (mind that this thread is in the Beta forum, not the Scorp/Monte forum ;) ).
In that case I would use a complete 2L FI engine with your 1800 pistons.The smaller combustion domes of the 1800 head results in a slight compression boost (vs. a stock head) when mounted on a 2L engine, which is a more straightforward operation to boost compression than changing to HC pistons.

Putting a 2L head on an otherwise-stock 1800 engine would thus reduce compression slightly, but that could be a Good Thing if one is also adding a turbo or supercharger (allows a bit more boost with reduced risk of blowing a headgasket), and a stock 2L FI topend makes an easy upgrade to FI for the older 1800s (also nice to have with turbo/supe, if the ECU can be reprogrammed/upgraded to blower-apropos tunage).

[Wallace]

Go and buy a pair of vernier pulleys . . . and get it right !!!

[Will]

To correct the Scorpion's lagging intake timing, just swap the gear. You don't need the flange, so you can drop a beta gear on. The timing difference is six degrees CRANK which is equal to 3 degrees cam, in other words if you were to redrill (theoretically) you would want it redrilled 3 degrees counterclockwise relative to the edge of a tooth. In your example, that would be 183 degrees clockwise...
So, the intake-cam retard only applies to Scorpions, not FWD US Betas (particularly my '79 carb'd 2L)? If so, then nevermind about the redrilling the intake camwheel dowel to re-advance the intake timing on a FWD Beta (mind that this thread is in the Beta forum, not the Scorp/Monte forum ;) ).
Correct, that is a Scorpion-only thing AFAIK


In that case I would use a complete 2L FI engine with your 1800 pistons.The smaller combustion domes of the 1800 head results in a slight compression boost (vs. a stock head) when mounted on a 2L engine, which is a more straightforward operation to boost compression than changing to HC pistons.

Putting a 2L head on an otherwise-stock 1800 engine would thus reduce compression slightly, but that could be a Good Thing if one is also adding a turbo or supercharger (allows a bit more boost with reduced risk of blowing a headgasket), and a stock 2L FI topend makes an easy upgrade to FI for the older 1800s (also nice to have with turbo/supe, if the ECU can be reprogrammed/upgraded to blower-apropos tunage).That's not what I wrote, please re-read: I wrote "use a complete 2L FI engine with your 1800 pistons." This makes a greater CR increase than swapping the 1800 head onto the 2L block, and- more importantly- it retains the superior 2L port geometry. Note that it also makes it an interference engine, but it solves your budget problems with the HC pistons

[Tom McGaffigan]

All US, 1800 Beta's, including the Scorpion, had altered valve timing as part of meeting the US emission requirements. The Beta’s had 86 hp and the Scorpion had 81 hp. Most likely the Scorpion had less hp due to the more restrictive exhaust system. The whole reason the 1800 wound up in the Scorpion was because the 1800 had already been Federalized and meet US requirements. If Lancia / Fiat had installed the 2 liter, they would have had to pay for Federalizing another engine, a very expensive and time consuming ordeal.
The valve timing specs on the US 1800 Beta’s are 5-53-53-5. Calculating the lobe centers gives you 114 ATDC for the intake and 114 BTDC for the exhaust. Typical European factory cams are at 110 ATDC and 110 BTDC. This is a 4 degree difference for both cams not just the intake cam. You will need to retime BOTH cams if you want to duplicate the European valve timing.
I agree with Wallace, just buy some adjustable cam wheels you will same time in the long run. I have never seen a set of inexpensive pulleys though so it’s going to be expensive horse power.
Tom McGaffigan

[Tom McGaffigan]

I see this Euro / cam thread has been going on for more than a year. Yikes! Here is some more info. The cam pulleys have 42 grooves (or teeth) so there is an 8.57 cam degree difference moving forward or backwards 1 groove. This is 17.14 crank degrees, a huge change! Moving 1 groove ahead or back will not achieve "euro cam timing". You might achieve bent valves though! In order to achieve the 4 degree (crank) change required to get the Euro timing you need to relocate the dowel pin hole .015 inches. This would be fine if you were using a new cylinder head that had not been surfaced because surfacing a head changes the valve timing. In addition, if you are using a head gasket that is different in thickness than the original then the timing will be different also. Just a few reasons to invest in a set of adjustable cam pulleys. With adjustable cam pulleys you could even go back and forth on the valve timing if there was a need.
Tom McGaffigan

[Will]

The difference we are discussing is the "relative" timing between intake and exhaust- the Scorpion has the intake retarded 5 crank degrees or so.

This measurement is critical because it determines overlap (and it is not affected by the surfacing of the deck or thickness of the head gasket).

The timing relative to crank (which is the one you are referring to) is a whole different animal, much looser figure due primarily to thermal expansion of the block, but a severely decked block may have some effect here as well, however because of the nature of the cycle of airflow, the crank timing is less critical. Even with vernier pulleys it is very difficult if not impossible to get this absolutely repeatable, owing to stretch and play in the belt, and the temperature change issue.

Of the adjustable pulleys, the only ones I've used are the Kents, and they are not the easiest to deal with either, they have a tendency to "creep" in the process of tightening them down because the intermediate bush between the bolt and pulley tries to ride with the bolt. I put delrin washers under my current set, but have not tested them yet- I'm hoping there will be enough friction between inner and outer pulleys to do the job without the extra "bite" of the bush.

In the absence of adjustable pulleys, $30 or so and a friendly local machinist with a rotary table will get the relative timing issue sorted, or a swap to steel wheel (which a lot of scorp owners due anyway, owing to the general paranoia of plastic pulleys) I think will do the same thing, based on the dowel pin being always 180 degrees from lobe center of #1, which is what I found when I degreed them.

[FiatFactory]

Well the differences in "euro" to US spec are more than just valve timing....though this is definitely different.

Valve sizes vary (according to my Lancia "data technicale" sheets) from 41.5 to 42 to 42.5 (nominal sizes)

According to gc (unconfirmed) the port choke sizes vary between different cylinder heads.....

The exhaust on a euro beta is a twin out manifold, US have single outlet.(this alone accounts for around 8HP, regardless of the cat conv)

Compression ratio in 1800 us spec betas is a pitful 8.0:1, an 1800 euro beta sedan is 8.9:1, the 1800 beta coupe is 9.8:1. (same as Australia)

All 2000 engines are the same CR... 8.9:1, except the post 83 models (which use a 43.5mm inlet valve) which it goes up to 9.0:1 as the combustion chamber is a different volume...unfortunately I dont have all the "DT" sheets for the US spec 2000 models (carb or FI) so I can't 100%confirm if the US 2000 engines are this CR or lower....

for carby betas, not only do the manifolds vary from US to "everywhere else" (according to the parts fiche, and what I've seen), but the butterfly and venuri sizes also vary.... if you give me the exact model code for a beta DMTR/DATR carb (1800 and 2000) as once again there are gaps in my "DT" sheets...

I do have a Weber "Bible" however, that has complete technical info for all carbs ever fitted to Fiat / Lancia's from '65 to '85, so if someone gives me the model codes of the US carbs, I can tell everyone precisely what the differences are....

And (though I'm having trouble finding the exact difference) the amount and rate of ignition advance is different too...

Every single one of these changes affects the Volumetric Efficiency of the engine, which in turn will affect its output... so just shifting the cam timing alone isnt going to make a huge deal of difference, until you do everyting else....

also, for my research, does anyone know the exact depth of valve flycuts (and compression heights if you have them) of the pistons for the US spec 1800's and 2000's... this will help me get some of the gaps filled in...

SteveC

[Will]

The exhaust on a euro beta is a twin out manifold, US have single outlet.(this alone accounts for around 8HP, regardless of the cat conv)

OK, what do you mean by this? Do you mean that you think the US Betas are all 4-1's? The later Beta Coupe/ Zagato, and I think HPE also but I can't say for sure, and possibly also the earlier Coupe/Zagato which I have not seen, have 4-2-1 in stock US trim. It is a two-part cast iron manifold. The upper part is a 4-2, the lower part is a 2-1.

Most enthusiasts here attribute all of the performance gain to the advent of fuel injection, although I think the manifold change is probably a significant factor. The stock 4-1 mani scares me it is so bad, especially on the Scorpion. The runners point right at each other, it seems a miracle to me that it works at all. The FIAT one seems a little better, but still IMO far from desirable.

[snoozin]

my 81 beta 2L rated @ 120bhp has 4>1, while my 81 and 82 131's rated @ 113bhp have the (or should that be a?) 2 piece 4>2>1. from memory the beta had a little more torq (178 instead of 173 nm, perhaps?), too.

I'd assumed part of the difference was that the 4>1 was better; is this not so? i haven't delved into comparing cams/ports/valves/comp...

[Tom McGaffigan]

The US spec 4 to 1 cast iron "header" is junk, especially the ones plumbed with EGR fittings. The 4 to 2 cast iron header is better. The term header usually applies to a tubular exhaust system that was designed to promote scavenging in order to aid in filling the cylinders with a greater portion of fuel and air mixture. The factory cast iron lumps are too short to do this effectively. Because of this, it becomes a question of exhaust flow out of the engine not aiding intake flow in. The 4 to 2 cast iron lump flows better than the 4 to 1 lump. For tuned tubular length headers a 4 to 2 to 1 will, in general, give better low end torque and less peak horsepower than a 4 to1 tubular header. So the 4 to 1 will give higher peak horsepower and less low end torque. :twisted:
Tom McGaffigan

[FiatFactory]

Will,

I don't have any fiches or DT sheet for the monte/scorpion or Zagato (which is just a coupe with the roof cut off!) so I'll take your word for it on the exhaust manifolds (we never got either model in Australia)

But here in Australia the 2litre beta's all have the long single outlet manifold, and simply changing this and the front pipe unleashes plenty of extra potential, back to near where it was in europe (120hp).

The twin outlet exhaust manifolds also vary (even though they have the same number cast on the outside) as the port sizes thru the usual 4166492 (?if my memory serves me well?) cast into it manifold vary depending on engine capacity... the one to use though is the manifold from an early 1400/1600 twin cam, these have a different number cast in (begins with a 415****, but can't be bothered digging a manifold out to look right now) and the ports thru the manifold are CONSIDERABLY bigger than any found in the 1800 type manifolds.

same with the front pipes, different engine capacities use a different pipe size, so if your going to do the upgrade, make sure the front pipes are generous in size....

The australian figure is actually 113hp output, and from what I can determine, everything else is the same (cam timing, CR, valves,carby,intake manifold) so this amount of difference is due to the exhaust manifold and the front pipe.

plenty of other similar examples (in the Fiat range) of similar differences.... 128 rally (in europe) was 67hp from 1300cc, the identical engine (CR, cam, intake, head) but with the addition of a twin outlet manifold produces 75hp in a 128 coupe... thats 8hp in a 1300, which shows the sohc is quite sensitive to exhaust (volumetric) efficiency, due to its non crossflow, all valves in a line configuration.

Snoozin, don't take the power figures quoted in the Haynes maunal or the Fiat owners handbook as gospel, there are plenty of discrepancies... the best one is our Australian market 78 X19's.... the owners manual quotes the output at 75hp ( :lol: ) which is of course the euro figure... but we copped the American spec exhaust on our 1300 models (sans the cat conv) and the american spec cam to meet our ADR's at the time.... true output is more in the range of 63 to 65 hp in a standard aust spec 1300 X19, despite what your owners manual tells you....


SteveC

[snoozin]

fair cop ;)

[Will]

Steve;

That's funny- you've never seen what I'm talking about, and I've not seen what you describe- apparently we are in very different markets!

I have the Scorp/ Monte fische and German Fische all in .pdf somewhere. If you would like, I can put it up somewhere you can download it, or if necessary, snail mail you a disk.

[SubGothius]

Just to clarify/restate my intentions, perhaps I could have chosen a better subject line for this thread, but by "Euro-spec tuning tricks" I mostly just meant to solicit relatively simple ideas for parts swaps/mods to bring detuned US cars closer to the stock performance levels (if not exact parts specs) of their Euro/non-US brethren (figuring such could be easier and cheaper than more serious Hi-Po mods involving piston swaps, etc.) -- not necessarily to catalog the actual differences US vs. Euro or how to "convert" a US car to match factory Euro parts spec. My ideal objective involved something along the lines of a top-end swap (head, valves, mannys and carb(s) together as a unit) and exhaust upgrade -- something a rank amateur backyard wrencher like me could feasibly tackle over a weekend (at least insofar as downtime for the car during the swap, not including advance prep time for the new top-end ;) ) and on the cheap, perhaps still passable for lenient CO-content emissions testing, which could be easily reversed if needed (i.e., if my car ever needed to get reg'd in CA again).

In the US, I gather (and correct me if I'm mistaken) that the 4-1 exhaust manny was a California emissions spec in particular (at least on '79s if not other model years), and that the 49-state US carb'd Betas (and also the '81-'82 FI Betas, perhaps for all US markets?) got the preferable 4-2-1 manny. I've also realized that my CA-spec '79 carb'd 2L Zag has a different headpipe (vs. 49-state US cars) connecting the manny to the cat (prolly since the union end of the 4-1 manny is higher up than the union end of the 2-1 segment of the 4-2-1 setup). BTW, this CA-spec headpipe apparently has two unique undercarriage hangers/isolators at the cat end (just in front of the cat, on the headpipe heatshield) -- basically a thumb-sized bit of flexy rubber with a washer and stud moulded into each end -- that may now be NLA, and both of mine are all tore up now, so I'm trying to figure out how to rig up something to replace those (maybe saw something similar for a FIAT 128 that could be suitable?). Right now, my exhaust system is sagging at the cat, leaving a HUGE gap 8O where the manny joins the headpipe underhood (props here to Lancia engineers having made that join spring-loaded for flexibility!), not to mention angling the tailpipe tip up enough that it rattles against the tail valence cutout. :roll:

I'm still curious about the notion of an 1800 head on a 2L block w/ stock 8.0:1 US pistons -- I'll grant that the 2L head may have superior flow (wasn't aware of that difference before, myself), but the "folk wisdom" I'd read had been that the 1800 head swap resulted in net gains in the end (so thinking the compression boost would make up for the loss in VE?). Also, what about other FIAT heads (esp. cheap'n'common ones)? I seem to recall some discussion (here or on the lanciabeta Yahoo! Group (http://autos.groups.yahoo.com/group/lanciabeta)) about the head differences for reclined Lancia applications (mostly a matter of oil drains?) actually being not significant enough to forbid FIAT heads on a Lancia (are Scorp engines more/less reclined than in other Betas, if that matters in this regard)... :?:

[sickchilly]

In the US, I gather (and correct me if I'm mistaken) that the 4-1 exhaust manny was a California emissions spec in particular (at least on '79s if not other model years), and that the 49-state US carb'd Betas (and also the '81-'82 FI Betas, perhaps for all US markets?) got the preferable 4-2-1 manny.

No, all US carb'd Betas had the 4-1 manifold. Only FI models got the 4-2-1. Same went for FIAT 1974+ 124's and other F/L DOHC models.


I've also realized that my CA-spec '79 carb'd 2L Zag has a different headpipe (vs. 49-state US cars) connecting the manny to the cat (prolly since the union end of the 4-1 manny is higher up than the union end of the 2-1 segment of the 4-2-1 setup).

1979 and up to mid '80 (carb'd) were unique models across the board. They were carb'd with cats and had slightly different smog control systems that previous 74-78 models. So when looking at a 1979 F/L model, just about anything goes.


BTW, this CA-spec headpipe apparently has two unique undercarriage hangers/isolators at the cat end (just in front of the cat, on the headpipe heatshield) -- basically a thumb-sized bit of flexy rubber with a washer and stud moulded into each end -- that may now be NLA, and both of mine are all tore up now, so I'm trying to figure out how to rig up something to replace those

Any decent exhaust shop can figure this out for you for must less effort/cost than you'll incur. Personally, I hate exhaust work and have found a small indie shop here I prefer to offload all that work to!


I'm still curious about the notion of an 1800 head on a 2L block w/ stock 8.0:1 US pistons

Unless you're planning bigger better mods, just slap on a fresh 1800 head and be done with it. It'll give you a bit of compression and, IMO, you won't notice the flow differences with a single carb setup, stock cams and basically stock exhaust. You can port match the intake and exhaust manifolds to the head which will help flow alll that you can hope for with modest carb/exhaust and stock cams.

[Will]

Word of caution here, Tye;

Do NOT tighten that spring-loaded clamp down too far, the one between the collector and pipe to the first resonator.
The inevitable result of this is that the two halves of the manifold separate and they have a very odd stud arrangement that is weak and nearly impossible to duplicate.
When this happened to me, I managed to weld the upper and lower "headers" together and reinstall. My problem then became that the increased torque of running nitrous thorugh the motor (The Zagato was my "testbed") caused the motor to twist so far on its mounts by the time the tires broke traction, that it neatly removed the exhaust manifold studs from the head.
Moral of the story: stiffen up the engine mounting and either keep the spring-arrangement of add a braid flex joint in place of it. This'll save you endless headache.

-Will

[KeppelmanJ]

I've been away from this list for a time and my head is swimming a bit reading this thread up to now. Let me add though that I have just put a fresh 1800 head on my stock injected 2 liter and swapped my original pulleys for current aftermarket replacements from International Auto Parts. These I figure are guaranteed to be euro spec in terms of cam timing since i doubt even in '81 that there were replacements for the us pulleys. I believe the cams are the same, US and Euro, so this engine should now pull close to the 122 HP the Euro 2 liter did. At first I was not impressed particularly with the increase, but as I drive it longer and harder, especially in the upper revs, it's impressive.

John Keppelman