Performance

[blue1]

I know this is a bit crude and boy racer like.

What is the typical performance of your Gilbern?
I would like to know to see if my Gilbern is running correctly as I can get good top end range over speed limit and shocking a lot of cars on the 3rd lane on the M25. But it is a bit sluggish on the acceleration in 2nd and 3rd.

[craig 12]

heres my take on it, in 1972 the zodiac lump was pulling something like an equivelant weight of a chieftan tank in the form of the billiard table mkv zodiac, they werent designed for speed, i recently had a 1972 mgb gt with a 1800 lump which was faster than the gilbern 0-60, if your gilbern is fast then i think youve been lucky, also after many years like all good things the hp will have dropped on a gilbern

a compression test will tell,

i remember seeing recently on top gear when they tested 3, 70s super cars and the horse power had dropped by about a third , and they were maseratis, ferraris, etc so if you have a fast one i think youre very lucky,
mine seems very slugish
but i have it for the uniqueness of it not the speed , remember moden cars have all sorts of gismos and diagnostics on them, probably a good sorted fiesta will be quicker than a gilbern 37yrs on

[Waylison]

A major consideration is unleaded low octane fuel used today.

When the Essex engine was designed we had four star on average 99.7 Ron. We are now asking the engine to run on unleaded at 95 Ron and super unleaded at 97 Ron. This has an effect on power EVEN if the timing of the engine is set to allow for the low rated fuel.

So if you are still having the timing set as per the original manuals, then you're not getting the best out of the engine. Running a lower Ron fuel means you need to retard the timing a few degrees ( depending on your engine / distributor / points set up.) I use an octane boost additive that gives me another 2 Ron (if added at the correct ratios). You can find ultra high Ron fuels....BP Ultimte at 102 Ron , Tesco Super Unleaded at 99 Ron (sold as Greenergy sometimes) and Shell do a few. It all helps to give the engine a chance.

I've found the most common cause of power drop off is wear at the points. I keep having to reset the points gap, because as they close up they retard the timing. Also reduces the power of the spark. I'm changing over to optical electronic ignition soon, once other stuff is sorted.

[Reddi-Eng]

Above about 75 bits start falling off mine so I'm a cruiser like Craig

[craig 12]

thats absaloutly brilliant derek, very fuuny , that made me laugh, im the same , i dont think id risk mine in the outside lane never mind 70mph..

[Waylison]

70mph! I'm still in 3rd at 70mph

I must admit the car gets a bit jittery at 120mph ( at RAF Marham track day I might add )

I must admit I wouldn't do those speeds with traffic coming the other way and trees around etc, after all, you are only in a plastic car

[Reddi-Eng]

My autobox has only got 3 gears, perhaps that's why

[raysmelt]

I have been using shell V Power at 99 Ron since having a reconditioned engine fitted a couple of years back. Cruises the motorways at 85 - 90 with ease and has enough power to surprise a lot of people driving modern saloons. It used to rattle a lot over 75, but fitting poly bushes, new kingpins and having the tyres properly balanced made a distict difference. All I get is a buzzing from the gearlever above 90

[trippdl]

I had a bad vibration from my red Mark III That may have been caused by an imbalance in the rear brake drums - not one of the things you would first consider looking at, so might be worth checking.

Also had advice along the way from a chassis specialist, that rubber bushings don't last all that long in any case, and regular replacement is a good idea. Also told not to use spherical rod ends, etc, due to excess harshness, but Tony has had them for years, and seems very pleased with his setup, so you might want to have a chat with him.

[Admin]

I have been using shell V Power at 99 Ron since having a reconditioned engine fitted a couple of years back. Cruises the motorways at 85 - 90 with ease and has enough power to surprise a lot of people driving modern saloons. It used to rattle a lot over 75, but fitting poly bushes, new kingpins and having the tyres properly balanced made a distict difference. All I get is a buzzing from the gearlever above 90

Is that buzzing or rattling?
Not knowing your car's history;
1 The Club now sells a much improved gear-lever bush kit, that more effectively 'decouples' the transmission of gearbox vibration.
2 Have you got the Thackery (wavey spring) washer on the large bolt through the lever, which applies a pre-load with out locking the lever?

[Waylison]

All I get is a buzzing from the gearlever above 90

Is that accompanied by blue flashing lights by any chance

My panhard rod has a solid spherical joint where it bolts up to the chassis and this is forever loosening off, even using nyloc nut on it! That then starts to 'chatter' on bumpy roads. Something on the 'list' to be sorted.

The rest of the car is polly bushed.

[raysmelt]

Admin It is definately a buzzing rather than a rattle. Will have to have a look which system I have.

Wayne, I was stopped by out boys in blue a couple times earlier this year. First time I was let off as it was night and no illumination on the speedo. They accepted that I was merely keeping pace with other traffic. Second time I was informed that I was well outside acceptable limits but they liked to see an "old car driven how it was intended!!!! Maybe I just have an honest face!!!