Fuel (lead) additives, what do you use ?

[haggispeed]

Just wondering what (if any) fuel lead replacement additives people use.
I'm running a FF X-Flow and sometimes an all steel 1700 X-Flow in my Classic Clubmans car.
I used to mix Bayford Thrust 4* leaded with Optimax (V power) but can't the 4* anymore.
I have been using Tetraboost for the last few seasons, which is a lead additive, I believe the only additive which actually has lead in it.
I know you can get proper 4* race fuel from the likes of AA Oil / Sunoco. not sure of prices.

So what do you use, additive, race fuels, nothing at all due to the relatively low mileage we do in our cars ?

[Gungebucket]

Hi Haggis, lead compounds were added to fuel to increase the anti-knock properties, and they were very effective at this. What no-one realised, until we took the lead out, was that the lead also protected the exhaust valve seats by coating them, and the valve seat area, with a protective cushioning layer. These days different materials are used for valves and seats and there is no longer a potential problem with Valve Seat Recession (VSR).
Your 1700 crossflow will have the seats cut directly into the cast iron of the cylinder head. I imagine that there really is no room in the head to fit hardened seats, particularly as you will almost certainly have large valves (probably at least 1.625" inlets and 1.34" exhaust .... from foggy memories!). You are therefore stuck with having to find something to protect the valve seats from VSR. The higher the engine speed and the hotter the exhaust... the worse it gets. A road car, just pottering around town, would probably never have a problem. Your 1700, however, is at the other end of the scale.

There are a number of compounds available that will provide some protection, but unfortunately nothing approaches lead in this respect. The non-lead additives available will protect road cars under normal driving conditions but will NOT protect your engine at race conditions. This is because these lead replacement additives deposit a protective coating on the seat area at low operating conditions, but the erosion rate is higher than the deposition rate at racing speeds. The result is that there is no protective coating left to do the job.

The other point, anti-knock, depends on the spec of your engine. The lead will give an octane increase, which your engine probably needs. I think if I were you I would stick to leaded fuel or use an additive containing lead (TML / TEL). It may be more expensive but, in the long run, a new race head would be a whole lot more expensive! Good luck. David

[Peter Mallett]

I believe you can only add Millers CVL (1 bottle per 20l) as an approved additive. Other than that you need to check whether you can run octane ratings in excess of 99, because that's what Sunoco produces and it is not permitted in some championships.

Hardened valve seats (as I have in my Essex) are cut into the head so I would think that if you can fit bigger valves, then you can fit seats to suit. Which means you can run 99 octane super unleaded.

[haggispeed]

I don't think anyone has used hardened valve seats in our formula, at least not that I'm aware of. Teraboost is designed for the race engine and what my engine builder recommends, not cheap but better than the normal road car products. There is no restriction on what additive we can use providing we do not exceed the 100 octane as per blue book.
Just wondered what others use as thinking of changing to Sunoco race fuel this year

[zefarelly]

average pump fuel is crap at the best of times, especially with high Compression ratios, I'm not convinced by any addittives, especially zany ones in flashy bottles from places like Halfords, although CVL seems to be commonplace.

Since its been available I've been using 4* type stuff from Sunoco, thay do various leaded fuels, legal and rocket fuel, they're as good as anything I've tried

[GORDON STREETER]

You can fit hardened seats with big valves in a crossflow as long as they are done properly. CTM in Essex did one for me and although I thought they would fall out, they didn't !
For the last 20 years I have run a wire mesh bag in the fuel tank with "lead balls" in it http://www.broquet.co.uk/ with very high compression and very high revs.
I still use one of my race heads that was made in 1990 that has good original (non insert) seats and has done thousands of race miles.

[Al Weyman]

Thats interesting Gordon, never seen those before.

[delta]

Yes this is interesting as i have a customer with a Volvo245 which has just done 300 thousand miles. He has a broquet fitted"which i turned my nose up when he first told me about it". Buy hey he runs the car on 95 unleaded and has had no probs what so ever.. We have been using Tetraboost in all the cars we run"seems ok".If Sunoco are at the race meeting we are at i will allways use their fuel.I just make sure we set all the engines up on what ever fuel we are going to use.

[GORDON STREETER]

Originally Posted by delta

.I just make sure we set all the engines up on what ever fuel we are going to use.

That's more important of course Iain. Although I had to run 95 unleaded at Mondello as that's all I could get hold of. It still run OK and I still won

[haggispeed]

Originally Posted by delta

If Sunoco are at the race meeting we are at i will allways use their fuel.I just make sure we set all the engines up on what ever fuel we are going to use.

Does that mean you'll change carb or timing settings if you're using a race fuel ?

[Peter Mallett]

Originally Posted by zefarelly

average pump fuel is crap at the best of times, especially with high Compression ratios, I'm not convinced by any addittives, especially zany ones in flashy bottles from places like Halfords, although CVL seems to be commonplace.

Since its been available I've been using 4* type stuff from Sunoco, thay do various leaded fuels, legal and rocket fuel, they're as good as anything I've tried

Millers was (not sure now) the only additive permitted by the MSA. And it worked very well with my engine prior to the hardened valve seats so I personally wouldn't knock it (no pun intended). I do use the legal Sunoco fuel now though and if I do events where they won't be, I buy a few cans in advance.

BTW. I think you'll find that Sunoco is not legal for CTCRC events.

[haggispeed]

Originally Posted by Peter Mallett

Millers was (not sure now) the only additive permitted by the MSA.

Peter, not sure that's true, although I wasn't racing last year but there was nothing in the Blue Book from 08 to state that you could only use Millers, just "...Only additves for the sole purpose of lead replacement are allowed"
I think 750 m/c may have restricted the make of additive

[delta]

You will never beleive this the Volvo had just turned up!!!. Hole in piston. Only kidding.Its MOT time.Previos question the Pinto's and FFords and Westminster we will run on 97 with Tetraboost or millers.All the Climax engines as well.FJ's F3's the Galaxie and anything else Sunoco 105.If Sunoco are at the meeting i will use the 105 in all the cars. Its expensive but does the job well.I have had no complaints from any of the engine builders.

[zefarelly]

I set mine up on unleaded now, a bit of leaded 4* is a treat!

I had balls in the tank of my old 1600E . . . 2 years commuting and 15000 miles and the head was shot.

[DaveGT6]

There are some that have experienced some issues with Millers additives (allegedly). It does seem that some engines can be quite sensitive to the amount added which can lead to plugs fouling resulting in lost power and misfire under high load.

[Al Weyman]

How come its just Millers thats legal whats wrong with a cheaper similar product like Lucas, thats a bit anti competitive isn't it?

[Peter Mallett]

Al,

It was to do with the type of additive. Millers was the only one that complied apparently.

[p261brm]

[QUOTE=zefarelly;2615767]I set mine up on unleaded now, a bit of leaded 4* is a treat!QUOTE]

Interesting, At Gaydon in the cells they were testing on leaded fuel then dialing it out. Had some tests done on various mixes the cleanest burn was Shell plus Tetraboost, and no trouble with bronze seats even up to 11,000rpm. 50/50 Spitfire Fuel/Shell almost as good, compression ratio varied depending on cams used 11/1 and 12/1. Re the expensive Sunoco did have a problem with that. When stood it left a residue a fine red/brown powder like substance, which played havoc with the felt filter in metering units. these were replaced a la Cosworth with extremely fine stainless mesh, kin expensive, still have a mass of the stuff. The Bayford 4*fuel YUK, suitable 1944 Churchill tank engines or un-fettled early BMC B series.

[zefarelly]

When I ran my most reliable engine ( not the most powerful, bt it WAS competitive) I only used super unleaded ( various UK/French/Belgian) and CVL, it was 'only' 11:1

it doesn't matter what I do to it at 12.7:1, it doesn't work for very long!

this year I have 2 engines, both 11.5:1 and will run super unleaded and CVL again I think, seats are not hardened, it'll get stripped and checked before thats an issue, a few years racing is fine from previous inspections, although I have run hardened seats without problems, as Gordon says, its a case of getting someone competent to fit them!

[zefarelly]

I've not had the luxury of testing fuels on the dyno, and we can;t use leaded on the one I use anyway because of the lambda sensor. although that must be an issue that can be rectified

[delta]

Originally Posted by DaveGT6

There are some that have experienced some issues with Millers additives (allegedly). It does seem that some engines can be quite sensitive to the amount added which can lead to plugs fouling resulting in lost power and misfire under high load.

Yep correct Dave seen that a few times with the Ford Junior engines .

[Al Weyman]

Originally Posted by Peter Mallett

Al,

It was to do with the type of additive. Millers was the only one that complied apparently.

At the time maybe but why shouldnt other companies produce an alternative or is that a silly (sic) question. And does anyone find these newer animated banner graphics a real pain on this site now and slowing down loading of the pages?

[haggispeed]

Blue book does say that the additives shoud contain, Manganese, Pottasium, Sodium or Phosphorus, guess that covers pretty much all of them ?
yes Al, agree with you ref the banners, so many web sites now thnk that everyone has super fast broadband connections that will quite happily cope with MB of data.

[zefarelly]

if we've got cars old enough to have leaded loaded joints and, leaded paint surely we can use leaded fuel

[Peter Mallett]

Al,

Which part of "was" means now?

Originally Posted by Peter Mallett

Millers was (not sure now) the only additive permitted by the MSA.

Originally Posted by Al Weyman

How come its just Millers thats legal whats wrong with a cheaper similar product like Lucas, thats a bit anti competitive isn't it?

Originally Posted by Peter Mallett

Al,

It was to do with the type of additive. Millers was the only one that complied apparently.

Originally Posted by Al Weyman

At the time maybe but why shouldnt other companies produce an alternative or is that a silly (sic) question.