Fiat 1600 PUSHROD Engine

[mack124]

Hi,
Has anyone ever tried performance tuning a Fiat 131 Pushrod engine?
I know what you are all saying. "Why bother? Just put in a twin cam"
That's what my brother and I normaly do, so conciquently we have a few 1600 and 1438 pushrod engines lying around and a 124 Special body and thought it would be an interesting and unique thing to do.

If anyone has done this I'd love to here from you.
Bye for now
Gill

[Acki]

Pushrod engine?

[mack124]

The pushrod engine I refer to is the over head valve engine that originaly was found in the 124 Saloon as a 1197 cc engine. Later it came out as the 1438 and then finally as the base model engine 131 at 1585cc. Up to about 1979 all of the Fiat 131 in Australia were 1585 OHV engines.

I'm not sure which came first out of the Over Head Valve engine or the Twin Cam but they are very similar, and quite a few parts are interchangable.

Thet were quite reliable as well.

[Guy Croft]

I've never built a pushrod Fiat, but i did a head a while back for a UK member, see photos, just an overhaul really, although I fitted my race springs because I could not get any OE ones, and as to whether it was a 'tuneable' head my thought was 'yes', I liked it. As far as the bottom-end goes I would have no problem setting it up with race rods and pistons and I imagine the rest of the setup would be straightforward enough to deal with. If the oil pump was an issue I'd convert it to dry sump.

The twin-cam is a beautiful setup and the port layout, big valves and cross-scavenge of the inclined valves makes it a very tuneable unit, plus having two cams gives a lot of freedom on in-situ cam timing. The pushrod Fiat unit is not as advanced (in tuning terms) but neither then is the Ford 'Kent' crossflow engine - a pushrod too, the old Formula Ford units (pre Zetec 1800 16v and of course certainly pre all alloy Duratec 16v 1600) gave about 105 bhp with flat top pistons, low CR, dry sump, flowed head on a single twin-choke Weber 32/36DGV and a lot more tuned up.

GC

[sumplug]

Its a Fiat head Guy, so it MUST be tuneable.
Incidently, last 2 years of production of 131 saw Fiat fit a overhead cam head to the block. This car now seems very rare. The block went to Lada who fitted their own head.

Andy.

[Unlpower]

I know of a few people who have played around with these engines.

A friend of mine here in the states is doing a 1600 stroker motor on his 1438 motor. I'm not sure what he has done for valves but he did have the head ported and polished. You use a 1608 crank and rods.

I think there are a couple of piston options but having them made would be the best so you can get a liitle more compression out of it. I believe you can use 1100 Yugo pistons - if you don't want to spend much money.(not 100% on the Yugo part) You should be able to get some decent power out of this motor.

Doug

[simon131]

The head in GC's photos belongs to me, Simon Ryle, and is from my 1976 131 1600 Special saloon.

I asked Guy to carry out a very simple overhaul of the head after the headgasket blew. I wasn't looking for a high performance re-work. My original plan was to have new valve seats sweated into the head to enable the engine to run on unleaded petrol without detriment to the engine's condition, but Guy informed me that a simple port cutting exercise would greatly improve its breathing.

The engine had (and still has!) only run for 15,000 miles from new so I didn't think a full rebuild necessary. Also, I was looking to keep the car as 'original' as possible, so didn't want a 150 bhp engine! ;-)

I must shamefully admit that after some four years of having the head refitted to the car, I have still not returned it to the road! I can report however, that the engine breaths far better after Guy's modifications, and when I initially refitted it ticked over at almost 3000rpm!

Incidentally, mack124, here in the UK (and the rest of Europe) the base 131 engine was a 1297cc pushrod unit, directly derived from the 124 1197cc unit, and was used in lesser spec models from the 131's launch in 1974 until the end of production of the 2nd series in September 1981.

When the third series (known by Fiat as 'facelift') 131 was launched in late September of the same year, the pushrod unit was dropped from the 131 altogether, in favour of an overhead cam unit, derived from the Strada/Ritmo range (although, obviously, still mounted 'front-back', and driving the rear wheels in the 131!). Also, the smallest engine capacity was pushed up to almost 1400cc, and was marketed as such throughout Europe. The 1600 single ohc remained 1585cc.