Lancia Beta Forum

Technical stuff => Tuning and competition => Topic started by: 75coupe on August 12, 2010, 07:49:49 AM

Title: 2 litre uprated engine rebuild
Post by: 75coupe on August 12, 2010, 07:49:49 AM
I am currently in the process of rebuilding my 2 litre engine for more power, as it is currently in a sad state having broken 2 top piston rings and badly scored big ends from the dreaded Beta oil surge problem (despite having a modified sump) and thought I would share the rebuild along the way. Funnily enough the engine did not burn oil and still went well even with the broken rings, but blow by was apparent out of breather....

This is a DIY rebuild, so cost has been a major consideration, but all machining has been done by a local reputable company.

The bottom end spec is:

New 84.8mm Fiat 105TC 1600 cast pistons - approx 10.5:1 CR in 2 litre
Crack tested, polished and balanced crank - std journal size
Crack tested Lightened flywheel, uprated spec clutch all balanced together with crank/front pulley.
Block deck has minimum required machined to ensure flatness
Modified Auxilliary driveshaft - removal of fuel pump cam lobe and plug oil gallery.
Modified sump with windage tray etc, 19 row oil cooler with remote filter, thermostat and 2 quart Accusump to cure oil surge problem and keep oil temp under control


43mm stainless modified inlet valves, 36 mm std modified exhaust valves
Bronze valve guides
3 angle valve seats
Mild porting around throat area and short side radius only - ports left virtually std size
Isky Uprated valve springs
Cams will be 304 degree 42/82/82/42 with 10.6mm lift which I already have
Vernier cam pulleys - essential for timing cams properly


Weber 45DCOE 152 with 38mm chokes on GC offset inlet manifold, walbro electric fuel pump with holley fuel pressure regulator


Std Beta bosch electronic system


4:2:1 mild steel header, 2 " single silencer with wide band Air/fuel ratio sensor & gauge.

Will post pictures soon, but if anyone has any ideas that I have not mentioned above, please let me know

Title: Re: 2 litre uprated engine rebuild
Post by: 75coupe on September 09, 2010, 12:50:15 PM
Here are some pics:

This is one of the reasons for rebuild and why you need an Accusump or similar for competition work, oil surge wrecks bearings!! Surprisingly crank OK, just needed polish!

Reason no.2 broken top ring on old 1800 piston (only 35 years old LOL!) compared to new cast 105TC piston at 0.8mm oversize.

Title: Re: 2 litre uprated engine rebuild
Post by: 75coupe on September 10, 2010, 09:57:59 AM
A few more bottom end pics, showing lightened/balanced flywheel - now 6.4kg vs 8.2kg for original. With Spec uprated clutch fitted it was 2kg lighter overall than std clutch/flywheel assy.
Crank has also been balanced with front pulley/cam gear etc.
Rods were weighed end to end and individually but were a matched set and all fairly close so were untouched.
Aux shaft has been modified so it does not have to be accurately timed. it has an eccentric lobe on the end to drive the mechanical fuel pump, which can hit no.2 con rod if it is not timed exactly. I have seen an engine completely wrecked because of this! I am using an electric fuel pump, so lobe is not required and is cut off and oil gallery tapped/plugged.
Block was rebored +0.80 mm to match new oversize Fiat 1600 Regatta/105TC pistons - available from Vickauto in the USA at a reasonable cost. This will turn the 1995cc block into a 2036cc block, but more importantly a high compression ratio of around 11:1 dependant on combustion chamber volume and head gasket thickness.
Engine was thoroughly cleaned, all core plugs replaced, oil galleries cleaned out with solvent and blown out, aux shaft bearings left alone as no longer available! Block painted black
Everything was assembled using Lucas engine assembly lube, new big ends, mains thrust washers, piston rings gaps were checked but found to be spot on

Title: Re: 2 litre uprated engine rebuild
Post by: 75coupe on September 10, 2010, 10:25:02 AM
Before fitting head I  set the TDC mark on front pulley accurately using a dial gauge on top of piston.
Also did a "dry build" to see what piston to valve clearance would be by placing plasticine around top of piston, fitting head with an old compressed head gasket and fitting timing belt (do not use a new gasket!). Cams were accurately timed and engine was turned over by hand a couple of revolutions with plugs out, feeling for any tight spots or locking of engine which would indicate valve to piston contact or chamber to piston contact.
Fortunately all was good so head was fitted properly, but not before cleaning all threads in top of block with a tap and lubricating bolts with oil.

Title: Re: 2 litre uprated engine rebuild
Post by: lanciamad on September 12, 2010, 08:59:43 PM
Brilliant stuff! :)
What about the conrods your using, are they forged items?
I've got a few things lying around the shed/garage so i'd like to compile my wishlist for an engine build and also the reality of how much it's going to cost :-\
I'll be really interested in your sump/accusump setup, very wise, I won't be chucking money at an engine inless I do everything in my power to keep it running sweet for a long time.

Title: Re: 2 litre uprated engine rebuild
Post by: 75coupe on September 13, 2010, 08:16:44 AM
Hi Marcus, no rods are standard low mileage items I already had lying around for several years. The standard items are forged anyway. If i was building an all out race motor I would be using forged pistons and race rods, but this is not going to rev past 7200 - (not deliberatley anyway!) which is Guy Croft's recommendation for cast pistons, and standard cast flywheel. If big revs are required, steel Flywheel as well! Cost then gets daunting.....I will be happy if it makes 160 - 170 BHP. Any more than this will be a bonus.

Title: Re: 2 litre uprated engine rebuild
Post by: 75coupe on September 13, 2010, 12:51:22 PM
Here are a few pics of sump mods, which work OK, but would probably have more drain holes in lower baffle plate and a bigger trap door.

I cut the bottom off a spare sump to start with and went from there with a spare block I had. Then set to work on another sump by cutting out all the standard internals, and welding in what you see.

It is not the prettiest of jobs, unfortunately most of the welding was done by yours truly with oxy/acetylene which was all I had at the causes a lot of distortion compared to MIG or TIG

Title: Re: 2 litre uprated engine rebuild
Post by: thirdbrother3 on October 13, 2010, 08:52:56 PM
looks like some great work, looking at doing a similar build in the spring. could i be very cheeky as ask for a ballpark build cost (labour aside). i need to do a head gasket, but was thinking of taking the opportunity to get more power (without going silly).

keep up the story and pics!


Title: Re: 2 litre uprated engine rebuild
Post by: 75coupe on October 14, 2010, 07:52:16 AM
Rebuild costs so far:

Rebore, machine block face, polish crank, lighten flywheel, balance with crank assy $500
New pistons, rings from Vickauto USA $335
Big end/main Bearings, thrusts, gaskets, inc HD head gasket $200
43mm inlet valves (not fitted yet) $85
Bronze valve guides (not fitted yet) $50
Accusump $250
Oil cooler & remote filter kit $220
Adjustable cam wheels $200
42/82 cams Vickauto USA $350
Weber 45 DCOE carbs & manifold secondhand $1450
4-2-1 tubular exhaust manifold S/hand $90
2" silencer & pipework (homemade system) $150
Electric fuel pump Facet or similar $100
Uprated clutch SPEC USA $350
NGK B9 EGV race spark plugs $80
OIl, filters, coolant consumables $100
76mm pod type air filter $50
Ford Focus ST170 radiator new $100 !!!
In head 71 degree C thermostat $10
All above in US dollars

That's off the top of my head for what has been done so far. Some of the items  like carbs & exhaust have been bought previously. All has been done over a 2 year time period. I don't want to add it all up......

You don't have to have the cams etc to start with, but you can rebuild a high compression bottom end which in itself will give an increase in power over std, then play with the head etc later as funds permit. The most expensive part was the carburettors, but these also gave the biggest single performance increase!

Title: Re: 2 litre uprated engine rebuild
Post by: 75coupe on May 14, 2011, 12:50:39 PM
It has been a while but here is an update on the rebuild. I was going to modify the head further and fit bigger valves etc, but time contstraints ruled this out, so I stuck with my previous head mods which were:

30 degree back cut on inlet valves, cleaned up ports, recut seats, shortened valve guides, 304 degree cams with 10.8mm lift. The cams required machining 0.8mm off the base of the inlet cam box to get the shimming right and I fitted adjustable cam wheels.

To keep the engine cool I did the following:

1. Ditch the external thermostat and fit an in head 71 degree C item. This requires blocking off the bypass pipe on the top water rail, which I did crudely by cutting it, crimping it together and welding.

2. I also modified the top rail and added a pipe to connect to the rear outlet of the head as per VX cars, this prevents overheating at No.4 when the heater is not in use.

3. The standard carb 35 year old radiator was not up to the job of cooling on 35 degree C days, and finding a series 3 style rad in Australia for a sensible price was near impossible. Eventualy I found a 2 liter Ford Focus ST170 radiator fitted nicely and has proven well up to the job so far. It is also less than half the weight of the original !!!

Title: Re: 2 litre uprated engine rebuild
Post by: 75coupe on May 14, 2011, 12:58:10 PM
A few pics of the completed engine and box prior to fitting:

Title: Re: 2 litre uprated engine rebuild
Post by: 75coupe on May 14, 2011, 01:18:13 PM
Engine in car with Focus radiator. I also fitted a 19 row oil cooler, oil thermostat, remote filter and accusump to keep the oil system under control from surge and heat.

Title: Re: 2 litre uprated engine rebuild
Post by: cheeky monkey on May 14, 2011, 06:14:27 PM
Superb work! . The Rad was a great idea

Title: Re: 2 litre uprated engine rebuild
Post by: 75coupe on February 20, 2012, 12:04:08 PM
Just a quick update,

I have had a VX head gasflowed with following spec:

43.5 mm inlets, 36mm exhaust valves, 30 degree back cut valves, 3 angle seats, reshaped guides, and is flowing over 105cfm at 10.6mm lift inlet, with 75% exhaust to inlet flow ratio, and is predicted to produce in the region of 180-190 BHP.

Title: Re: 2 litre uprated engine rebuild
Post by: archigraphe on September 06, 2012, 01:07:45 PM
HI, nice work . I hope a day accessing this quality...

Can you inform me about the expected torque  and power of this engine.

What type of race do you practice ?

Title: Re: 2 litre uprated engine rebuild
Post by: 75coupe on September 17, 2012, 08:03:20 AM
Hi there,

Just a quick update, head fitted with GC3A cams and triple valve springs, 38mm chokes in the Weber 45DCOE carbs. needs to be properly dyno tuned, but could not get in to my local one due to backlog, so DIY jetting with a wideband lambda sensor it was, fortunately GC's recommendations were close....

Power? suspect around 170BHP - still to be confirmed.

On first impression I was not overwhelmed, engine less peaky than before, but wants to rev a bit more now, saw 8000rpm easily once, but have set limit of 7200 as only have cast pistons. Will pull full throttle from as low as 2300rpm, but happiest at 4000+. Old cams used to like 5000 to 7000, so now more flexible.

Car did first race meeting a few weeks ago and performed well enough to keep up with all sorts of well sorted Fiats and Alfas on the straights, even managed to overtake a Ferrari F355......Not sure if he had his foot buried though.....

It's a shame I had to fit the airbox and cold air intake to the carbs as it muffles the glorious Weber intake noise somewhat, but makes the car easier to live with on the road.

A couple of shaky Videos: ( (

Some in car action on the track, this is where I overtake the Ferrari (towards the end of the clip): (



Title: Re: 2 litre uprated engine rebuild
Post by: DeXiTroN on April 02, 2020, 11:36:46 AM
Please can I ask which model Ford Focus radiator is used??


Title: Re: 2 litre uprated engine rebuild
Post by: Nigel on April 03, 2020, 10:42:10 PM
It's the one from the ST170.

This applies to the UK model though. I guess research will determine whether it's available in
the same spec in Aus.