Race Engine Forum UK

Hi everyone,
I would like to know the following, about a carefully built [ by me ] basically standard Lancia delta 1600 GT, which as far as I know has the same spec as the Fiat 105tc. I have this engine along with an early type 5 speed, in a much modified MG midget. Not having the original info, ----- handbook, rev counter etc, I am wondering about the safe maximum revs to subject it to.
I have treated it carefully during the initial break in period, and am now up to around 400 mls
It seems to be running well, and feels like a very free reving engine.
There seems to be lots of info on this excellent site about the strength of the 2 litre cranks, rods etc, but what is the spec of the smaller engine's crank. I'm thinking 6500 max, [ but hoping someone will say 7000. ]
Looking forward to any replies, thanks.
P.S two oil and filter changes already, ----- I'm a very careful person !
[ basically, don't want to blow it up after so much work ! ] Midge.

7000? Really the safe limit is governed by the OE valve springs. You might get away with higher (4 times out of 5..) but 7000 nad even 7500 is perfectly safe. How much useable power your engine will develop at that speed is a good question.

I know your engine is basiclaly standard but just for interest: As to what the engine can take - and here I'm talking about a GC prepped unit with race springs - I have personally set the rev limiter on an engine like yours with std rods, crank, pistons to 9500 and watched it race at that speed (and survive many years later) at Valence Hillclimb in the early 90s. The driver was Robin Cooke and the car was the front engined 'Mincia' featured in my book.

At full race spec, well, that short stroke unit will go way higher.

GC

Thanks Guy , very nice to know.
I am always aware that many things discussed about 'tinkering' with cars for competition, and general messing about with our road cars for the fun of it are two different things.

The only mods on my engine are modified Abarth headers from a 130tc, and twin DHLA, finally [ after much trial and error ] running really clean and responsive with small venturis [ 30mm ] and 120 mains. The idles ended up larger than I would have guessed before I got a clean response,but this allowed the pump jets and strokes to be minimised for economy. This was the first time I'd really knuckled down to studying these carbs, along with the similar Webers, and I realised it's essential if you want to make any sense at all from the bewildering array of possible settings and numbering codes, but all very interesting, and I would imagine, given enough time and patience, you could match the performance / economy of injection.

Hope the above might be of interest to someone .
Midge.