Fullauto head before and after comparisons (2014)

Eddie,

Angie sold me FullAuto head number 101 freshly delivered from Australia about a year ago!

I know Mick has used some in full engine builds for customers, who would then find it difficult to compare/comment. At least one of those is destined for a Peter Williams works Norton replica.

We know that Comnoz has used some in customer builds too, also likely to be difficult for them to comment too.

So, assuming 50 percent still on coffee tables or in bikes not yet running.....from 50 odd installed and running you don't have a huge pool of bikes out there that can offer the comparison....if you factor down to Forum members it may be as few as 25, several of those are going to be racers....so most likely modified in some way even if only minor like faced for compression.

My guess is that most likely only something like 10% or less went on with no other changes!

Looking forward to you posting a comparison in about June next year ;-)

Eddie, I think the only way you will ever know if there is a distinct advantage with the Fullauto head is if somebody like yourself is progressively developing a racer and noting the performance changes. The average guy with a street bike would be unlikely to easily detect an improvement. The trouble is that if the racer is to be used in competition many owners keep schtum if they find advantage in anything.

There are 132 Fullauto Technologies heads out there somewhere.

Still haven't got my money back.

#79 is gradually getting closer to being on the road, but it replaced a planed RH4 head and what turned out to be a race cam is also now being replaced so no direct comparison will be available here.

Mr Fullauto must have done development to end up with the current design of his heads ? What are his claims for improved performance ? And on which bikes was the development carried out ?
I've seen heads reshaped to full hemisphere, some welded up and remachined to a long oval chamber with wide squish bands. The D shaped exhaust is one I'm not familiar with. These things have obviously given benefit on various engines. I'm sure Fullauto would not have made such an expensive item based purely on speculation and theory. One thing I'm certain of and that is the commando engine is superior to the same capacity Triumph engine, however that might be due to many things other than the cylinder head features.

Well, the "development" of the heads was to make them superior to the originals in material, heat treatment and by use of CNC machining to make them more uniform as regards to accuracy of machining and equality of combustion chamber volumes etc. The port profiles were done by Jim Comstock using over thirty years experience in making Nortons go faster. My personal bike, a '73 850 MK1 is currently being put back together after two and a half years off the road due to a bad accident which bent me more than the bike. Up until that time, I'd covered 18,000 miles on it with Fullauto Technologies head #2, the first production head, following on from five pre-production heads, which were mostly scrapped due to various reasons, including porosity in a couple. After this, all heads were pressure tested with none failing due to porosity after these.

My motor is basically standard with a Mikuni VM 34 and TriSpark ignition. I changed nothing when the new head went on and the motor pulled harder and felt stronger right through the rev range, lacking in top end as single Mikuni carbed bikes do. No changes to the engine spec are planned this time around. It should be back together by the end of the year and I'll report back on what we find in the motor when we take the head off.

Out of 132 heads sold, I've had one warranty claim, where the head was immediately replaced. When the suspect head came back, it was sent back to Harrop Engineering and was scrapped.

Any other questions? Ask and ye shall receive.

Forgot. These heads were not manufactured for racing. The idea was to manufacture a suitable replacement head as none was available. Their suitability for racing is a bonus.

acotrel said:

Mr Fullauto must have done development to end up with the current design of his heads ? What are his claims for improved performance ? And on which bikes was the development carried out ?
I've seen heads reshaped to full hemisphere, some welded up and remachined to a long oval chamber with wide squish bands. The D shaped exhaust is one I'm not familiar with. These things have obviously given benefit on various engines. I'm sure Fullauto would not have made such an expensive item based purely on speculation and theory. One thing I'm certain of and that is the commando engine is superior to the same capacity Triumph engine, however that might be due to many things other than the cylinder head features.

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Specifc individual features are not unique Alan, take a look around the rest of this site, but here is a D port Norton done some time ago.

http://mez.co.uk/mezporting/d_shape.jpg

Dunno if anyones mentioned here ( on this thread ) that the Fullauto has more meat , for ' opening out ' if that's youre game , than the stock suckers , in the intakes . Just for the wecord .

ntst8 said:

#79 is gradually getting closer to being on the road, but it replaced a planed RH4 head and what turned out to be a race cam is also now being replaced so no direct comparison will be available here.

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#82 is just waiting on new springs to arrive

Dkt26 said:

ntst8 said:

#79 is gradually getting closer to being on the road, but it replaced a planed RH4 head and what turned out to be a race cam is also now being replaced so no direct comparison will be available here.

Click to expand...

#82 is just waiting on new springs to arrive

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Which did you go for?

Beehive. One day I plan on building a race bike. I figure that the top end will be able to follow me wherever I go. Next rebuild I want an uprate the cam and the js1 radius setup will suit very well.

Matt Spencer said:

Dunno if anyones mentioned here ( on this thread ) that the Fullauto has more meat , for ' opening out ' if that's youre game , than the stock suckers , in the intakes . Just for the wecord .

Click to expand...

Not quite correct. There's more meat around the thread for the exhaust ports for bronze inserts if needed. No extra around the inlet ports.

Fullauto said:

Matt Spencer said:

Dunno if anyones mentioned here ( on this thread ) that the Fullauto has more meat , for ' opening out ' if that's youre game , than the stock suckers , in the intakes . Just for the wecord .

Click to expand...

Not quite correct. There's more meat around the thread for the exhaust ports for bronze inserts if needed. No extra around the inlet ports.

Click to expand...

There is forethought for you, assume that along the way some owners will abuse/fail to protect the heads in the same way they abused/failed to protect the originals.....makes sense to me....

And since the general concensus is that improved performance across the rev range can be achieved with a smaller rather than larger port, the other part was a logical decision too. Adding metal is generally a good idea....except, as an example, my TTi box weighs significantly more that a standard box, and a racer always likes lighter. I know the trade off here. But I have had to grind small amounts of this 'excess' metal from both my Maney cases and TTi box to get them into my frame with adequate clearance.

My question is; is there anywhere where additional metal has caused occasional issues on the FullAuto? Externally I can't see that because it looks very close to the original. I was thinking more about less clearance in the pushrod tunnel as an example?

Nope, They're half a kilo lighter than a standard Norton head and they are so close dimensionally that they are even slightly cosmetically challenged, just like the originals, just not quite so cosmetically challenged.

Fullauto said:

Nope, They're half a kilo lighter than a standard Norton head and they are so close dimensionally that they are even slightly cosmetically challenged, just like the originals, just not quite so cosmetically challenged.

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Well I think they're awesome, thanks for all the effort you've gone to putting them out there for us.

Anything I do with my motor these days is about increasing torque. I am currently looking at programmable ignition systems and different needles for the Mk2 Amals. Also I'm going to try playing with a combat cam, by advancing it 6 degrees. I suggest that once you enlarge the inlet ports in a cylinder head there is no easy way back. The strength of the commando engine lies on it's mid range torque. As soon as you raise the usable rev range you run into expense. I know all the theories about increased revs giving more power, however if you improve the torque characteristics and raise the overall gearing aren't you achieving the same result without the potential of a major blow-up ? If you raise the rev range, the internal forces on the crank etc. increase in a squared relationship. The fact is that if the fullauto head improves torque , that makes it worthwhile in my opinion.

Got one from Mick Hemming, would be impossible for me to tell the difference in behaviour.... Just beautifully made, plug and play with JS beehive/valves/Maney barrels.

The only oil dripping from it comes from the stupid stubborn front leaking fork :x

Fork leaking? check the seal slider bore..some times in the past , owners may have prised out the seal and scored the bore..apply sealant to the seal sides.

Xpongebob said:

Got one from Mick Hemming, would be impossible for me to tell the difference in behaviour.... Just beautifully made, plug and play with JS beehive/valves/Maney barrels.

The only oil dripping from it comes from the stupid stubborn front leaking fork :x

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Will check this on winter overhaul :wink: