TS1 Cylinder Head Change

[ROClarke]

I am thinking of either fitting the BGM RT head to my TS1 or the Casa Radial head in a bid to aid cooling and reduce the risk of blowing a head gasket.
The BGM head is a machined billet which I feel may not be so sensitive to warping,the Casa head is dropped forged but seems to have potentially better cooling qualities than the BGM due to the head fins themselves.

Has any one any experience of either or have a preference to help me if my decision ?

I also run a Trail Tech engine temp sensor under my spark plug currently, so access to this is important

Cheers

[ULC Soulagent]

Am I right in saying that the bgm head will need machining as it drops in the barrel by 3 mm.
Currently looking at this option as I’ve a spare Bgm 225 head to go along with a iron lined ts1 225 that I want too sort out.
The casa is a direct replacement only requiring two dowels put into the barrel for centralised location

[Knowledge]

I am playing with heads at the moment, and one of the things I notice about the new-to-market heads is how much heavier they are. When you think about it, the head needs to be a good heat-sink, and volume of metal helps this task. On the other side of the coin, the heads used by Innocenti and other manufacturers needed as light as possible to reduce mass-manufacturing costs. This kind of leads me to think that Innocenti heads are redundant, and if you want something extra to remove the heat from the combustion chamber, a head containing more metal, or a head with better fins, is required.

Heavy is good. More fins can be good too, but can also restrict the passage of cooling air to other parts of the head.

If a head is designed to drop into the barrel, it need not (in many cases should not) go all the way into the barrel. The shim/gasket system used on the Mugello head can be used adjust the swish, while the protruding combustion chamber on the head becomes merely a mechanism by which the combustion chamber can be centralised.

I will follow this thread with interest.

[Warkton Tornado No.1]

It would be fantastic if we could all refer to a definitive guide on cooling of our engines, as the majority of users on this Forum must surely have subjected theirs to some modification.

Perhaps there may eventually be a test conducted by a respected body, such as a magazine, but it would undoubtedly mean a thorough, methodical process as we were able to read recently, as was the case with the comparison of the proliferation of 'Clubman' exhausts.

Let me say now, that whatever modifications are performed, unless the profiles of the piston & 'head are correct & concentric with the squish @ it's optimum (for which opinion varies, but 1.0 mm has never let me down) then you are compromising the ability of any 'head to perform it's function.

Personally, I have a number of modified kart & motorcycle engine cylinder heads as well as Lambretta specific 'heads that were produced with the remit of higher heat transfer in mind, but these were often used with no actual scientific proof of them being better than the standard generic OEM heads, other than when direct air cooling was employed. Principally, such heads are used because the finning is North/South & they are less likely to distort, though their surface area is probably no greater than an OEM 'head, despite some having a larger size & mass, as in the case of the MBD item.

Undoubtedly, some of us follow a different path to reach an objective, & if you consider heat sinks that are employed on a PC, those that are proven to give better results rely upon upgraded fans to enable their superiority.

Like Fast&Furious, (who has teased us with his very sound ideas upon the principle of improving the basic 'head cowling design ) my belief is that there are substantial improvements to be gained by modifying the standard tinware employed to reduce any losses.

For instance, for those of us that use the Smallframe flywheels, whether points based or the AF type, simply adding a ring to the flywheel cover to match the fan's smaller intake diameter & reduce the gap, really does reduce any chance of cavitation & increase flow through the system. To augment the quantity of air, one easy modification that was employed years ago (when Group Four were still using iron barrels with fan cooling), was to effectively make the LH floorboard an air scoop by adding a thin (aluminium) plate to force air through a cutout that matched the fan intake. For my own engines, this simple modification enabled down jetting & the consequent increase in power, so it was definitely worth doing in that scenario.

I apologise if this response is somewhat 'off target' to the original Post, but sometimes the best cure to an anticipated problem is not necessarily what tends to be the norm & gets selected, but to consider other components within the chain & if that makes me the Devil's Advocate, so be it.......

[dickie]

Knowledge, the volume of metal only helps in the short term. So at start up, it will stop the head temperature from rising as quickly. Or, if you shut off and weaken the mixture, you'd have a bit more breathing space than you would otherwise. So it is a benefit. It doesn't however keep the temperature down over longer periods at steady load; this is down to material thermal conductivity, surface area, air temperature, air density and air flow. I'm not saying that it isn't good, it clearly is, but not in the way that many might expect. Material, surface area and a good airflow are the keys here.

[ROClarke]

Good point on the amount of metal Dickie,surely on the negative side as well,it would it not take longer to cool down,thus risk heat related problems even if the air flow is good.
On the plus side it would I would have thought be less likely to warp.

[Knowledge]

Ok, I acknowledge the value of the comments in the last two posts. You both make good points. The principle of a heavy head sits comfortably with me.

[dickie]

Ok, I acknowledge the value of the comments in the last two posts. You both make good points. The principle of a heavy head sits comfortably with me.

Me too, which is why I fitted an avanti head on my TS1. But I'm a pedant.

[Fast n Furious]

When I built my TS1/200, I had the head made to my own CAD specific design by Mito in Italy. The lingo translation was a bit iffy initially, but they were happy to make it to my specs.
Principally, its a standard dimensioned, aircraft grade billet ally, 7 point fixing, centre squish head.
Its uses a 10mm long reach extended nose plug, located in the usual place, at an angle where the spark gets generated smack centre of the combustion bowl for maximum combustion efficiency.
Trouble free performance for the last 6000 miles, Still running fine on the original plug. Well happy

[ROClarke]

When I built my TS1/200, I had the head made to my own CAD specific design by Mito in Italy. The lingo translation was a bit iffy initially, but they were happy to make it to my specs.
Principally, its a standard dimensioned, aircraft grade billet ally, 7 point fixing, centre squish head.
Its uses a 10mm long reach extended nose plug, located in the usual place, at an angle where the spark gets generated smack centre of the combustion bowl for maximum combustion efficiency.
Trouble free performance for the last 6000 miles, Still running fine on the original plug. Well happy

Whilst I respect and admire your choice F&F,you have not really answered my post,or are you suggesting I choose the BGM head ?

[dickie]

Personally I'd go for BGM as it appears to have a greater surface area to volume ratio.

[dickie]

Personally I'd go for BGM as it appears to have a greater surface area to volume ratio.

[ROClarke]

Will the BGM head go straight on after any adjustments for squish ?

[dickie]

Will the BGM head go straight on after any adjustments for squish ?

This one will

https://www.lambrettaspares.com/spares/bgm-parts/lambretta-cylinder-head-225__230-road-cnc-mbgm/mbgm0384.html

[Scooterdude]

I think there are two kinds of BGM heads, the drop in verity than come with the cylinder kit and have eight fixing points and the other ones for retro fit that fit flush with the top of the cylinder like a standard head with the standard four point fixing, both machined from billet but at £168 not cheap.

[hullygully]

A/F's also do a Mamoof head, loosely based I think on the Avanti, dowelled too.
I put that on my TS1 245 & recently did the 4 x Nations, on motorways, all the way from Hull to Fermanagh & back, with NO heat issues.

[Storkfoot]

A/F's also do a Mamoof head, loosely based I think on the Avanti, dowelled too.
I put that on my TS1 245 & recently did the 4 x Nations, on motorways, all the way from Hull to Fermanagh & back, with NO heat issues.

I am just in course of fitting a CHT to my 9.5 compression ratio Mammoth which is now on my TS1. Pleased so far though, and gut feel is that it is running significantly cooler.

My only concern with the Mammoth is that you can’t just stick the head on some wet and dry on a glass plate to check it is perfectly flat.

[ROClarke]

I think there are two kinds of BGM heads, the drop in verity than come with the cylinder kit and have eight fixing points and the other ones for retro fit that fit flush with the top of the cylinder like a standard head with the standard four point fixing, both machined from billet but at £168 not cheap.

Seems a bit cheaper from scooter cologne.

[ROClarke]

Don't you need a different head cowl for the woolly mammoth storkfoot ?

[Storkfoot]

Don't you need a different head cowl for the woolly mammoth storkfoot ?

True, that does add to the cost but still cheaper than that bgm, I think.