Cost of unleaded conversion?!
Discussion
How much should I expect to pay to convert a 1600 lotus twin cam cylinder head to run on unleaded?
I spoke to a renowned engineering firm and he quoted £960 at least, this sounds loads! He did say the lotus head is a less straight forward job than most with the shimming and something else.
I spoke to a renowned engineering firm and he quoted £960 at least, this sounds loads! He did say the lotus head is a less straight forward job than most with the shimming and something else.
As already said.
What is he doing for that price?
It could be to take into consideration that he may have to sleeve the head, renew valves etc but it does sound like that will be on top if required.
Have you shopped around?
Any contacts through the club?
I think I'd be asking there rather than here.
What is he doing for that price?
It could be to take into consideration that he may have to sleeve the head, renew valves etc but it does sound like that will be on top if required.
Have you shopped around?
Any contacts through the club?
I think I'd be asking there rather than here.
As others have said, it depends exactly what your specialist calls an unleaded conversion. My first thoughts were it's not too far out if this is a recognised marque specialist rather than a local engine rebuilder. Looking at parts prices, admittedly very rough estimates based on the Burton site and you're looking at
Ex. Valves, £20 each, £80.
Inlet valves, £20 each (assuming 1.56", sprint size ?) - £80
Valve seat inserts - say £20 each, £160 ?
That's very roughly £320 and assuming parts listed by Burtons are suitable for unleaded. I'd also expect to do the valve guides at the same time and replace them all with bronze ones (£8 on Burtons, so £64 total ?) which pushes the parts alone bill to almost £400 as a minimum.
If your guy has done a lot of these then he'll likely be pricing in some welding if the waterways look corroded and then certainly skimming afterwards. Remove the old seats & guides, replace with new and cut seats, lap valves, insert new guides. I'd expect that to be at least a couple of days skilled labour, which at around £35/hr gives your the rest ?
It seems about right, maybe shave off a few quid but remember the head casting is quite expensive to replace if it gets bodged by someone who hasn't done similar things before. If he's mentioned shimming valves then it sounds like he'd be rebuilding it to at least cam stage as well, which has got to be another hour at the very least.
Personally I'm just waiting until the valves start pocketing on mine and given the low mileage these days that could be many years. There's anecdotal evidence from the US guys that they don't seem to have had problems with unleaded, so unless your engine is already in bits (or broken) then maybe it could go on the back burner ?
Ex. Valves, £20 each, £80.
Inlet valves, £20 each (assuming 1.56", sprint size ?) - £80
Valve seat inserts - say £20 each, £160 ?
That's very roughly £320 and assuming parts listed by Burtons are suitable for unleaded. I'd also expect to do the valve guides at the same time and replace them all with bronze ones (£8 on Burtons, so £64 total ?) which pushes the parts alone bill to almost £400 as a minimum.
If your guy has done a lot of these then he'll likely be pricing in some welding if the waterways look corroded and then certainly skimming afterwards. Remove the old seats & guides, replace with new and cut seats, lap valves, insert new guides. I'd expect that to be at least a couple of days skilled labour, which at around £35/hr gives your the rest ?
It seems about right, maybe shave off a few quid but remember the head casting is quite expensive to replace if it gets bodged by someone who hasn't done similar things before. If he's mentioned shimming valves then it sounds like he'd be rebuilding it to at least cam stage as well, which has got to be another hour at the very least.
Personally I'm just waiting until the valves start pocketing on mine and given the low mileage these days that could be many years. There's anecdotal evidence from the US guys that they don't seem to have had problems with unleaded, so unless your engine is already in bits (or broken) then maybe it could go on the back burner ?
Edited by b2hbm on Monday 15th February 08:53
Edited by b2hbm on Monday 15th February 08:54
We run our S3 on standard fuel and the heads not been converted, occasionally add some additive and sometimes a tank of high octane unleaded.
You really need someone who is recommended to work on your head. I would ask on Lotus Elan Net as there are a lot of horror story's about poor engineering damaging twin cam heads.
Link http://www.lotuselan.net/forums/active-topics.html
TonyR
You really need someone who is recommended to work on your head. I would ask on Lotus Elan Net as there are a lot of horror story's about poor engineering damaging twin cam heads.
Link http://www.lotuselan.net/forums/active-topics.html
TonyR
forest07 said:
We run our S3 on standard fuel and the heads not been converted, occasionally add some additive and sometimes a tank of high octane unleaded.
You really need someone who is recommended to work on your head. I would ask on Lotus Elan Net as there are a lot of horror story's about poor engineering damaging twin cam heads.
Link http://www.lotuselan.net/forums/active-topics.html
TonyR
That's interesting Tony, when you say standard fuel, do you mean the normal unleaded ? I've not used any of the lead replacement additives for a while now but I have been either using the high octane stuff or adding octane booster to the normal unleaded thinking that they needed the octane rating. Do you get away without pinking on standard fuel ? That would make life so much easier.......You really need someone who is recommended to work on your head. I would ask on Lotus Elan Net as there are a lot of horror story's about poor engineering damaging twin cam heads.
Link http://www.lotuselan.net/forums/active-topics.html
TonyR
Brian
b2hbm said:
forest07 said:
We run our S3 on standard fuel and the heads not been converted, occasionally add some additive and sometimes a tank of high octane unleaded.
You really need someone who is recommended to work on your head. I would ask on Lotus Elan Net as there are a lot of horror story's about poor engineering damaging twin cam heads.
Link http://www.lotuselan.net/forums/active-topics.html
TonyR
That's interesting Tony, when you say standard fuel, do you mean the normal unleaded ? I've not used any of the lead replacement additives for a while now but I have been either using the high octane stuff or adding octane booster to the normal unleaded thinking that they needed the octane rating. Do you get away without pinking on standard fuel ? That would make life so much easier.......You really need someone who is recommended to work on your head. I would ask on Lotus Elan Net as there are a lot of horror story's about poor engineering damaging twin cam heads.
Link http://www.lotuselan.net/forums/active-topics.html
TonyR
Brian
No pinking at all on standard unleaded Brian, I'm also surprised on how good the fuel consumption is compared to a crossflow engined Caterham.
Wow, that is interesting news and thanks for posting.
For some reason I had it in my head that when "unleaded" came out all the mags were claiming it was 2-star equivalent and only modern engines would run without pinking. Thinking their experts would know best, I never bothered to check it out and as 4* disappeared I just carried some additive when I wanted to fill up.
I will try some plain unleaded next time I fill up and see how it goes. Thanks.
Brian
For some reason I had it in my head that when "unleaded" came out all the mags were claiming it was 2-star equivalent and only modern engines would run without pinking. Thinking their experts would know best, I never bothered to check it out and as 4* disappeared I just carried some additive when I wanted to fill up.
I will try some plain unleaded next time I fill up and see how it goes. Thanks.
Brian
a waste of money:
its an alloy head...for that reason steel valve seats are already installed from the factory.
therefore those engines are unleaded friendly from new.
ever thought that those engines also ran in the US? where leaded fuel was banned at beginning of the 70ies.
same with alfa romeo (full alloy) twincam:
it was unleaded friendly ever since.
but some "clever" parts-dealers came-up with the idea promoting unleaded friendly heads or conversions somewhere in the 90ies....and people bought it.....because the had been afraid that the engine might get dmaged...they all believed the "stories" the dealers told them.
i run several (cast-iron) ford x/flow powered cars...none of them has been converted, all are hard driven, even on track, none of them ever had problems with the valves...and i even do NOT use ANY addhitives!!!
its an alloy head...for that reason steel valve seats are already installed from the factory.
therefore those engines are unleaded friendly from new.
ever thought that those engines also ran in the US? where leaded fuel was banned at beginning of the 70ies.
same with alfa romeo (full alloy) twincam:
it was unleaded friendly ever since.
but some "clever" parts-dealers came-up with the idea promoting unleaded friendly heads or conversions somewhere in the 90ies....and people bought it.....because the had been afraid that the engine might get dmaged...they all believed the "stories" the dealers told them.
i run several (cast-iron) ford x/flow powered cars...none of them has been converted, all are hard driven, even on track, none of them ever had problems with the valves...and i even do NOT use ANY addhitives!!!
Edited by GinG15 on Saturday 20th February 23:37
Hi,just to add another take on this well discussed subject.A friend who raced a variety of sixties race cars including a type 26 Élan swore by a mixture of 1part avo fuel to 5 parts unleaded.He was involved in the petrol chemical industry so I assume he was well informed.( avo fuel was obtained from the local flying club)I would be most interested in hearing comments from the more knowledgable .Regards Baz
bazjude2998 said:
Hi,just to add another take on this well discussed subject.A friend who raced a variety of sixties race cars including a type 26 Élan swore by a mixture of 1part avo fuel to 5 parts unleaded.He was involved in the petrol chemical industry so I assume he was well informed.( avo fuel was obtained from the local flying club)I would be most interested in hearing comments from the more knowledgable .Regards Baz
Probably more to do with octane boosting and anti-knock properties than protecting the head/valves.Gassing Station | General Lotus Stuff | Top of Page | What's New | My Stuff