Fulvia HF 1600 compression test results

[jmspear]

I have had my 1970 HF 1600 for a month now and jobs done so far are:

drip tray repaired under carbs
Carbs fitted with new gaskets and refurb kit installed (they were leaking)
new carb to manifold rubber - ouch this was expensive
refurbished engine breather can
stay bolt from engine to air filter repaired and actually connected - hence whyI guess the carb rubbers were splitting
new air filter - ouch again
air filter housing resprayed, was rusting inside from condensate coming from engine via non serviceable breather can
headlights replaced with RHD units (car imported from holland) - outers only
headlights upgraded and new wiring with relays - massive improvement in light output, highly recommended
silver top facet installed for priming after lay up
MoT
UK registered
new fuel pipes
new windscreen washer pipes and this afternoon, I finally got round to compression testing my new baby.

Car is on original engine (1970) and has done around 70,000km's according to the (massive) paperwork file the engine has never been apart - and the results are:

#1 = 210 psi
#2 = 200 psi
#3 = 205 psi
#4 = 195 psi

I am assuming that this indicates the engine is in good health?

off to look at all the suspension rubber bushes now to check if any need replacing.

car drives beautifully, good job as I drove it back from Holland after purchase!

[DavidLaver]

headlights upgraded and new wiring with relays - massive improvement in light output, highly recommended


What did that entail?

[jmspear]

basically I bought new outer RHD headlight lights (can't remember the brand) but think any 51/4" lights fit, this gives you new reflectors, then I bought a set of osram night breaker from euro car parts, they had a 60% off sale on over xmas, H1 for the inner lights and H4 for the outer, (I stuck with the OE inner bowls even thought the reflectors are getting a little dull with age now, then the smart bit I bought a new loom from ebay - https://www.ebay.co.uk/itm/H4-Headlight-Relay-Wiring-Harness-System-2Headlamp-Light-Bulb-Fix-Dim-Light-fo12/272828977933?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649 basically this takes a live feed direct from the battery to the lights via a set of relays and also your original loom plugs into it to activate the relays, so when you turn on the lights as usual, the relays are activated and you get a direct feed with very little voltage drop direct to your lights, voila very bright lights as you have uprated (but legal) bulbs with no voltage drop.

I have done the same upgrade on my Alfa GT junior and also Duetto to equally good effect, in fact the lancia is much better as it has quad main beam with the H4's and H1's all activated on main beam.

[Jai Sharma]

I don't know about the absolute values one way or the other but the compressions look nice and even.

[davidwheeler]

Compressions very impressive indeed!   Youy would usually recon about 10 bar - 150 psi so you are doing very well.   

[simonandjuliet]

Must admit, the values are better than mine ! They do seem good and consistent across the bores - don't touch and enjoy ! Does the engine use any oil ?

Interesting mod on the lights - seems very reasonable price-wise as well

[jmspear]

Thanks for the feedback on the compression test results, very happy with them as stand alone values, now even happier when compared to the forum expertise, no doesn't use any oil so it will be spanner free

cheers

John

[nistri]

Not wishing to be a great nuisance, however very high compression values might indicate a lot of carbon deposits inside the chambers and on the valve faces. Not unusual if the carburation was not working properly. However, I would just keep an eye on the situation without taking the head off. Andrea

[jmspear]

is it worth using one of the additives that are supposed to clean up carbon deposits combined with an "italian" tune up ? I do think it has been running a bit rich (not checked the mixture yet, but seems to be on idle, on a proper run (before compression test) the spark plugs are very clean and nice colour, but initially before carb overhaul they were pretty black (the carb overhaul was seals and new float needle valves as it was leaking fuel underneath). Or just not worry as correct mixture and time and decent runs will correct??

[fay66]

Many years ago i used a holts decarboniser,  i shot a load of it down each plug hole of a poor unsuspecting Austin A30. Next morning I spun  it over with the plugs out, soaking up the remains with a rag over each plug hole.
I then started the car and the street disappeared in a huge cloud of smoke akin to a very good 1950's smog. After the cloud of smoke dispersed, I took it out into the nearby countryside, an ran it until there was no more smoke.
Afterwards there was a distinct improvement.
Although I think a drop of diesel left in the cylinders overnight has a similar result.
Brian
8227

[Jaydub]

Hi John
The compressions are very high for a road engine, you would struggle to get those on a race engine running about 11/12:1 compression ratio. Maybe your gauge isn't reading correct. However they are even so that is good.
I wouldn't use any of those DIY chemicals as you will run the risk of dislodging chunks of carbon which can easily stick on a valve seat and cause a loss of compression and necessitate head removal. As Andrea said use it, give a long hard run of 15 to 20 miles and then adjust the mixture etc if need be.

[lancialulu]

The compressions are very high for a road engine, you would struggle to get those on a race engine running about 11/12:1 compression ratio. Maybe your gauge isn't reading correct. However they are even so that is good.

I wondered about the high figures. Time to calibrate I suspect. What kit did you use as I am thinking of getting a tester for my HF engine (narrow spark plug thread)?
Tim

[jmspear]

Thanks, I think a good run is the answer, it has just driven back from Holland so it got a pretty good run then!! I used a halford compression tester I have had for about 20 years, plus I bought an appropriate thread adaptor for the gunsons compression tester which fitted the halfords kit a treat - the gunsons adaptor is after all just an adaptor from one spark plug thread to another.

the initial tests (first run) were similar spread but about 180 psi - 190 psi, then I did a second test and finally a third when I got my best readings, maybe the car had drawn so much fuel in by then it was equivalent to a wet test, when you add oil to get a second figure sealed by the oil??

[davidwheeler]

I remember first time we put the Lambda angine together (about 1965) having liberally oiled everything.  She also disappeared in a cloud of blue smoke and was driven to the end of the road to wait until it had cleared.   She was promptly named f*rting Annie.  Happy days!

[nistri]

Using a standard optic probe through the plug holes, it is possible to inspect the condition of the chambers. If the cylinder head had been skimmed one or more times, that is another reason to raise the compression values. Andrea