Difference Between 330 GTC and late 2-mounts 330 GT Engines?

As I understand it, the modified 209 engines with two engine mounts used in the 330 GTC and the
late 330 GT 2+2 have exactly the same block. Just looking the engines, the GTC and GT have
different carburetors. But are the any internal differences in the materials used or different forms
of connecting rods, pistons, crankshafts, what ever. Do the two engines have different camshaft
profiles? Different compression ratios? The RPM limit stated for the GTC is 7,000; for the GT
it is 6,000. Why is there this difference?

 

The quoted maximum revs for the 1964 330 GT 2+2 was 6600, not 6000 but brochures were also made for later 330 GT cars stating it as 7000 rpm. The compression ratio was the same at 8.8/1 on 330 GT and 330 GTC and both making 300 BHP (clamed).

330GT cars are quoted as having Weber 40 DCZ/6 carbs whereas the 330 GTC was said to have used both the Weber 40 DCZ/6 and Weber 40 DFI/2 the latter of which had a larger choke diameter, up by 1mm to 28mm, and different jetting. I don't know if the 330 GT also actually used the Weber 40 DFI/2 carbs when it changed over from the 4 mount engine to use the 2 mount tipo 209/66 engine.

 

Just a thought. Perhaps the snorkel type air filter that the 330 GT engine was updated with, and many earlier cars converted to, changed how it revved?

 

Could it also have had something to do with the way the engine was loaded differently due to the different gearbox ratios/final drive between 4 and 5 speed 330 GT and the 330 GTC?

 

All two mount 330 motors are the same internally. DCZ carburetors were used on the earlier cars, and DFI used on later cars, but there is no definitive change-over time frame. As to redlines on tachs, yes, generally the 2+2 used 6,600 and the GTC used 7,000, but no engine differences. Actual engines made about 250-260 bhp, a good shop just dynoed a fresh all stock motor at 267 bhp and everybody was thrilled. That is a very strong 330 engine.

 

So it would not hurt my 330GT engine if it hit 7,000 RPM for a few minutes?

I often run the engine at about 6,000 for a few minutes after the 30 minutes it takes for the oil temperature to come into its proper range.

 

Lowell: Remember these motors are almost 50 years old now. Take that into consideration. All the single cam outside plug engines starting with part way through the 250 run use the same valve springs, including the Comp motors (GTO, LM, GTB/C). That will tell you something about Ferrari's quality in that era. A 250 GTO will break a valve spring at about 9,400 rpm (don't ask how I know this). I would have a lot more faith in a engine that was never apart, than in a engine I did not know how or who assembled. You are on your own!

 

I know the complete history of the car. It is spelled out in Kerry's registry s/n 8855. It has about 79,000 miles. The bottom of the engine has never been
apart. The heads were rebuilt about 25 years ago by Bob Wallace (of Lamborghini fame) in Arizona. New valves, guides, and springs were installed. The
guides have a grove and some sort of O-ring so that the car never smokes. I vaguely remember (perhaps incorrectly) that these guides were introduced
in the Daytona. 8855 was built in late 1966, so it is a little over 51 years old. I have the complete build sheets. There was a window in time around 2001 when
Ferrari would email you copies of the build sheets if you sent them photos of the serial plate, internal motor number, transmission number, and differential
number. They made a mistake and sent me the dyno sheet as well. The engine was not super strong --- it made around 240 vapor horse power.

 

There was a perhaps too implicit question here: Since the heads have been rebuilt to modern standards, can the engine be run at 6,600 RPM with no damage even though the the rest of the engine has not been touched from new?

Anyone care to voice an opinion on this?

 

It was 30 years ago that Bob Wallace rebuilt the heads but the health of the whole engine from the bottom end through the cylinder block, bores/pistons/compression, cam chain/sprockets, tension/timing, valve guides, valves, springs, clearances and carburettors, gaskets, the whole drive train and the whole car would need to be considered. I would ask myself if everything has properly been kept on top of and maintained properly, but even then the engine could go bang at any time but would be less likely, imo. It's all about reducing the risk of a big failure.

 

The oil and coolant have always been changed once a year --- the car typically has less than 1,000 miles a year, but has been driven on 30 or 50 mile trips fairly often. Come to think of it, the heads were reworked about 20 years ago. It was shortly before I got the car and was told to re-tighten the head studs, which I did as well as checking the valve lash -- one or two valves needed to be changed slightly. At that time the distributors were gone through and timed on one of those wonderful old machines. Since then, except for a few (maybe unnecessary) spark plug changes (the old plugs looked fine, not to hot or cold, no carbon build up), nothing has been touched on the engine.

The engine sounds nice with no valve or other noises that I can hear. It is kept in a garage and so never gets cold. It starts with a couple or three turns. I pride myself in keeping the original starter that turns so slowly but still starts the car.

OK: So what should be the rev limit on this engine?

 

It may well be fine but your engine would benefit from being checked and properly set up by someone with experience of these engines. I may be wrong and may have misunderstood your post but it sounds like it hasn't been done in 20 years/20,000 miles? Presumably it would have been de-coked at the time the heads were gone through? Have the piston rings ever been changed? Personally, before revving the engine very highly again I would at least get the following checked: electrics/ignition timing, cylinder compression with leak down test, tension of the cam chain, valve clearances need checking every 6000 miles, mixture and synchronisation of the carburettors. I think the gearbox and axle oil need changing every 3000 miles. The brakes, chassis, steering, wheels and suspension also need checking if not done already.

Dyke can advise you better than I can. Also FChat member Bob Zambelli who has 180,000+ miles on his 330 GTC, most of which were by him, and has rebuilt the car and engine himself, I'm sure could tell you how high he revs his engine.

 

I said at most 1,000 miles/year. Probably about 10,000 -- 12,000 miles in twenty years.

I have a four post lift so that it is easy to work on the car.

Gearbox and axle oil changed a couple of years ago.

The car is regularly greased.

I phoned Mr Pierce when I moved to a higher altitude. He told me, don't touch the Webers if the engine runs fine.
When I had the air filter off so that I could repair to heater hose shut-off valve, I took the opportunity to play with
the German synchrometer that is used to set Webers which I bought some time ago and had never used. The
carbs were so close that I made no adjustment.

About 5 years ago, I completely rebuilt the rear suspension, taking everything apart and using a press to push
in new bushings. I had to make special gadgets to hold the springs in place.

When I first got the car, Kerry and I repaired the front suspension.

I have rebuilt that terrible fuel fuel pump on the engine several times. I hope I finally have got it right.
(The rear gas filter was changes a few years ago.)

As I said, the ignition timing was very accurately set about 10 -12 000 miles ago. What would make it wrong now?

The only things in your list that I have not done is to check valve lash, chain tension, compression/leakdown.

I do take car of the car. So someone should tell me what the rev limit should be.

 

I am no mechanic and please excuse me if I am wrong but it sounds to me if quite a few maintenance tasks have been missed such as the cam and ignition timing. Personally, because of this, I wouldn't be driving the car at all let alone revving a 50 year old engine to its 7000 rpm red line. Refer to your Owner's Manual for the routine maintenance that needs doing from page 40. If you don't have it see here: https://www.manualslib.com/manual/1191815/Ferrari-1964-330-Gt.html?page=40#manual

 

To me, the top end and tuning is the least of your risk revving an unknown engine, it is the rod and main bearings I'd be concerned with. The sump cover can be dropped and caps removed to inspect most of the bearings in a GTC.
I have a habit of removing the sump cover on every old car I acquire regardless of what I've been told has been done to it, there is much to learn down there. I've found chunks of bearings, bearings worn down to the backing, badly scored crankshafts, sludge so thick it threatened the pick-up, etc. These surprises were on engines that were tuned and running pretty good, encouraging vigorous use, but I'm sure glad I looked down under before whacking the right side pedal very hard.

 

There are many things to check and consider if you want to run the engine to the 7000 rpm red line such as age related metal fatigue and wear in use. To run the engine to its red line I'd be checking that the crankshaft, its bearings and con rods are in good condition and to spec in addition to the block, top end and all the other stuff mentioned. To some this is the big down side and the nightmare to old classic cars generally, especially considering the cost, and to others this actually is the joy of it with the satisfaction achieved in getting everything right, whether they do the work themselves if they have the necessary skill or get professionals to do it.

 

What does age have do do with it if the car has not been driven many miles?

From Wikipedia, the free encyclopedia

In materials science, fatigue is the weakening of a material caused by repeatedly applied loads. It is the progressive and localized structural damage that occurs when a material is subjected to cyclic loading. The nominal maximum stressvalues that cause such damage may be much less than the strength of the material typically quoted as the ultimate tensile stress limit, or the yield stress limit.

 

Unlike wine, cars don't improve with age and when left standing.

Seriously though, I'm sure they can take it, but a cylinder block and head for example are always under stress being screwed tight against each other by studs with a gasket in between and are subject to high temperatures unevenly around them even though water cooled so will expand and contract unevenly so can in some circumstances crack. I've heard of this happening on Aston Martin 6 cylinder engines. Also heard of porous blocks on 365 GTC/4s. Though I don't know if they were porous when newly cast or whether that is something that develops over time.

 

The car does get driven, just not high miles.

I thought that all Ferrari engine blocks of that era were porous when they were made --- I thought that that is why they were painted internally.
And I do not think that stress = fatigue.

 

Old wives tale.

 

Actually, let me take that back.
In a certain aspect it is fairly accurate assessment.

 

I used to regularly take my 330 GT to 7000 RPM, it sounded great but it did not really make power up there. For the quickest acceleration shifting at just over 6000 RPM seemed to pull the best. If you are comfortable it is running well, I would go for it. However you are the only one that can decide if you want to risk it.

Cheers Jim

 

Stress can or may lead to fatigue.

Don't forget perishing rubber parts for example carburettor diaphragm rubbers, corrosion of mechanical parts, and not forgetting internal engine corrosion which can occur when an engine is not being used. Don't want to sound overly negative but these are definitely things that occur over time.

Any pictures of your car to post? I think 330 GTs are great.

 

Gee, which carb parts are rubber???

How does the inside of an engine full of oil get corrosion?

There are a large number of photos of my car. Google "Kerry 330 registry" and go to S/N 8855.

 

As I said the diaphragm in the carbs are rubber. My father had a 330 GT when I was a young boy in the early '70s. I well remember him replacing the diaphragms on the carbs. Actually I remember him doing that on all the cars he had including a Miura SV and 365 Boxer.

Regarding internal engine corrosion don't forget that during combustion an equal amount of water by weight is produced as the petrol that's burned plus corrosive substances as part of combustion are produced so you have water plus these corrosive substances in the cylinders and exhaust valve ways for starters. Water/moisture and these corrosive substances also enter the crankcase due to "blow by" which are the catalysts to producing rust/corrosion or galvanic corrosion in differing connecting metals such as between the iron liners and aluminium cylinder block of a Ferrari Colombo engine. On some Ferrari engines including Daytona and Boxer the steel camshafts run directly in the aluminium head without bearings so galvanic corrosion could possibly occur there??? You have already said that Ferrari engine blocks are porous. If this is the case water may enter the internals that way. Moisture may enter through the engine breather as well. I'm sure somebody can explain this better than me.

I had a look at the pics of your car on Kerry's site. It looks very nice indeed.