Race Engine Forum UK

SPECIFICATION
Fiat Ritmo Abarth 130TC reconstruction to Fiat Ritmo Abarth 125TC ( older model)
ENGINE: 2,0 (1995 ccm)
Engine block was lower – 2mm, because I have pistons from engine 1,6 ( it has bigger crown head).
Serial valves – only turned on a lathe
Serial camshaft from 1.6 TC
Adjustable camshaft drive pulleys
2x Solex 40 ADDHE + pump Facet
GEARBOX : seriál only final drive ratio 3.765
(17/64) from 1,6
CHASSIS: shock absorbers from company HP Sporting CZ
CAR BODY: complete reconstruction, safety frame, and…………..

Horsepower max ONLY 138 !!!???? Serial 130. I do not know why! Serial exhaust pipes 4-2-1 is not adequate and I am making new now.

MODEL POST!

I have very much enjoyed seeing this and it makes a nice change to see the member himself (and son) in the photos, for some reason there appears to be a reluctance to do this among other members; a great pity since it adds an important human dimension. This is supposed to be a forum, after all, not a rather 'dry' on-line manual...

Two points regarding your power. First, the 2 liter 131 engines were equipped with camshafts of nominal lift 9.9 (130TC 10mm), nominal - clearance of 0.4/0.45 in/ex = true lift, whereas the 1600 models had only 9.5mm, so in your case it is likely - measurement will prove this - you are losing 0.5mm of lift which you don't want to do..

Secondly there is much to be had form valve/seat modification on this head, the GC DVD tells you exactly how and what difference it makes. In terms of port size if the head is actual 130TC with the 43.5mm inlets it already has very big ports - 36-35mm approx and unless you are prepping to StIII+ (by my reckoning 175bhp and over) they don't need to be made any bigger, but gains from smoothing the port and esp the SSR (short-side radius where the valve throat runs in to the port floor). If it's a 131/132 head with (nominal) 42mm inlets then the ports need opening up to 36 (at port face) to 34mm at narrowest section. It is worth pointing out that the 130TC head actually had very little by way of SSR, you don't want to chop it off completely, and the reason for that is that it has a much lower port floor than other models. The latter is a perfectly natural consequence of having a bigger port on that type head by the way, the optimum shape is (in my view) round (not D shaped or any other) and if you make the port big, it's going to have a lower floor.

With 130TC cams and head and twin 40s, even with high CR 1.6 liter pistons, the engine is only going to produce about the same as standard, 130bhp or so but with a bit more mid range torque from the higher CR. Fully prepped GC style this is going to go up to about 145bhp, most of that gain coming from the valve/seat and SSR mods. Now add 45 DCOE on 36mm chokes and you're going to be in 155bhp territory - even on the 130TC cams. Those 43.5mm valves are capable of taking the power way higher with a change ot good billet comp cams too. Of course we know it's not just a question of 'power' (ie: bhp) - it's the area under the torque/rpm that really counts. Of course if you lots everywhere, the top end bhp and straight line speed will be high too. But often it's the acceleration from terrific bottom-end and mid range torque that makes the car driveable and exciting. An engine that develops an exciting 190 bhp (which that 130TC head definitely can) at 7500 and soes 140mph (if ever such a thing was safe in a 130TC) but has how can I put this nicely, er, 'modest' torque below 3000 and does 15 miles-to-the-gallon is going to be a bit irksome after a while for road use.

Well done for the way you have executed this project and presented it to us. It is great to see another 130TC being 'saved', and there is plenty of scope for GC style 'supertuning' on this one!

GC

Hi Guy, hi all,
Because mine engine wasn't for me sufficient, I made other from Fiat Coupe 16VT

Excellent!

Thank goodness there are still a few people out there pursuing a proper hobby!

G

and because with new engine I needen new modification of coachwork, so I am right made drive 4x4 from Fiat Tempra SW :-)

after montage 29.3.2009

You need to go round that carefully prepared car and make sure that ALL paint is removed where there is a threaded joint eg: nut & bolt.

Paint is soft and allows the preload to come off and the joint can work loose. If you want paint - paint after bolting-up.

Just a quick tech note,

GC

Small progress..

A nice project & thread with some really good photos!

Well done!

GC

Very thanks Guy

Hi all, small advancement from last time :-)

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