Any experiences with Timing chain Simplex conversion kit ?
Discussion
The simplex chain simply reduces the mass that the engine is turning as opposed to the duplex. Your unlikely to see any power gain from the chain alone. Racing green believe it puts less stress on the timing gear set.
Conversely obviously a single chain may not have the ultimate durability of the duplex.
In terms of upgrades if you up your budget a bit, probably a carbon air box is your best bet and some decats.
Conversely obviously a single chain may not have the ultimate durability of the duplex.
In terms of upgrades if you up your budget a bit, probably a carbon air box is your best bet and some decats.
Sagi Badger said:
Less mass so less energy to spin up. Light weight flywheel is probably safer, cheaper and likely to benefit more. You will only see a difference in low gears.
J
This seems to be the perceived wisdom. I can understand it making a difference with the clutch disengaged so the engine can rev more freely (at the expense of reduced smoothness at idle since that must be what a heavier flywheel does). Very little mass to the engine / flywheel moving parts and the extreme is the F1 engine which can change revs very rapidly. But is not very easy to use from a standing start. Or so I understand having never driven one...J
However, when connected to the 1100kg of the rest of the car, a few kilos off the flywheel (or even fewer off a timing chain) must make less difference to acceleration than the amount of pies I have eaten this week (it was a lot of pies).
I looked into this earlier in the year when I had my engine out but was advised against it on durability grounds.
The view of my trusted mechanic was that although it would reduce the rotating mass in the engine (usually a good thing) it didn't make sense to replace a duplex system with a simplex. This is from his experience of years of preparing engines for racing where one of the first changes that was made was to replace a simplex system to a duplex one for reliability.
I took his advice and stuck with the duplex system although it wouldn't have cost me any more to go with the RG setup as I had the timing chains and ancillaries renewed in any case.
Pure conjecture: doesn't the FFF head have a lot more rotating mass than the standard? If that's the case, it would make sense for RG to go down the route of reducing the mass elsewhere in the system e.g. by introducing the simplex system to keep the responsiveness of the engine.
^ the paragraph above may be complete b
ks - just my idle musings about a subject that I am by no means an expert in.
On to the other point regarding the lightweight flywheel. I went down this route (again engine out, clutch renewed as well so cost little or nothing in terms of labour). Has it made a difference to the way the car drives? Not that I have particularly noticed, if I'm honest, although I was without the car for some time and not able to do a back to back comparison. It does pick up a little quicker, I guess, but given the effort involved in replacement, I think that there are likely better mods out there in terms of price vs, performance...
The view of my trusted mechanic was that although it would reduce the rotating mass in the engine (usually a good thing) it didn't make sense to replace a duplex system with a simplex. This is from his experience of years of preparing engines for racing where one of the first changes that was made was to replace a simplex system to a duplex one for reliability.
I took his advice and stuck with the duplex system although it wouldn't have cost me any more to go with the RG setup as I had the timing chains and ancillaries renewed in any case.
Pure conjecture: doesn't the FFF head have a lot more rotating mass than the standard? If that's the case, it would make sense for RG to go down the route of reducing the mass elsewhere in the system e.g. by introducing the simplex system to keep the responsiveness of the engine.
^ the paragraph above may be complete b
ks - just my idle musings about a subject that I am by no means an expert in.On to the other point regarding the lightweight flywheel. I went down this route (again engine out, clutch renewed as well so cost little or nothing in terms of labour). Has it made a difference to the way the car drives? Not that I have particularly noticed, if I'm honest, although I was without the car for some time and not able to do a back to back comparison. It does pick up a little quicker, I guess, but given the effort involved in replacement, I think that there are likely better mods out there in terms of price vs, performance...
darkmark07 said:
I looked into this earlier in the year when I had my engine out but was advised against it on durability grounds.
The view of my trusted mechanic was that although it would reduce the rotating mass in the engine (usually a good thing) it didn't make sense to replace a duplex system with a simplex. This is from his experience of years of preparing engines for racing where one of the first changes that was made was to replace a simplex system to a duplex one for reliability.
I took his advice and stuck with the duplex system although it wouldn't have cost me any more to go with the RG setup as I had the timing chains and ancillaries renewed in any case.
Pure conjecture: doesn't the FFF head have a lot more rotating mass than the standard? If that's the case, it would make sense for RG to go down the route of reducing the mass elsewhere in the system e.g. by introducing the simplex system to keep the responsiveness of the engine.
^ the paragraph above may be complete bks - just my idle musings about a subject that I am by no means an expert in.
On to the other point regarding the lightweight flywheel. I went down this route (again engine out, clutch renewed as well so cost little or nothing in terms of labour). Has it made a difference to the way the car drives? Not that I have particularly noticed, if I'm honest, although I was without the car for some time and not able to do a back to back comparison. It does pick up a little quicker, I guess, but given the effort involved in replacement, I think that there are likely better mods out there in terms of price vs, performance...
The FFF has a lot less mass in it (with the Simplex we are talking kilos), so don't think so! The view of my trusted mechanic was that although it would reduce the rotating mass in the engine (usually a good thing) it didn't make sense to replace a duplex system with a simplex. This is from his experience of years of preparing engines for racing where one of the first changes that was made was to replace a simplex system to a duplex one for reliability.
I took his advice and stuck with the duplex system although it wouldn't have cost me any more to go with the RG setup as I had the timing chains and ancillaries renewed in any case.
Pure conjecture: doesn't the FFF head have a lot more rotating mass than the standard? If that's the case, it would make sense for RG to go down the route of reducing the mass elsewhere in the system e.g. by introducing the simplex system to keep the responsiveness of the engine.
^ the paragraph above may be complete b
ks - just my idle musings about a subject that I am by no means an expert in.On to the other point regarding the lightweight flywheel. I went down this route (again engine out, clutch renewed as well so cost little or nothing in terms of labour). Has it made a difference to the way the car drives? Not that I have particularly noticed, if I'm honest, although I was without the car for some time and not able to do a back to back comparison. It does pick up a little quicker, I guess, but given the effort involved in replacement, I think that there are likely better mods out there in terms of price vs, performance...
As for the durability - mine has done over 5k of very hard driving on it now, and nothing bad to report. It's not racing of course!
Lightened flywheel - the only thing I noticed is that is is harder to 'launch' the car - the bite is more pronounced.
My personal opinion is that I would rather have the additional durability afforded by the duplex chain on a road car engine. For what amounts to a pretty negligible improvement in engine rev response, I'd rather not have the worry of knowing that my timing gear is possibly more likely to fail and in doing so destroy my expensively modified engine at the same time.
Don1 said:
The FFF has a lot less mass in it (with the Simplex we are talking kilos)
Was referring to the head itself, not the whole setup but thanks for the info, I stand corrected 
ETA: isn't there a planned development of the FFF thank includes variable valve timing? This will add additional rotating mass to the top end of the engine so the simplex system to redress this change would make a lot of sense.
Edited by darkmark07 on Saturday 7th September 17:14
Don1 said:
The FFF has a lot less mass in it (with the Simplex we are talking kilos)
Are you saying the bucket followers weigh less than the moving part of a finger follower ?
Also , seeing as the camshafts are moving at half engine speed then any weight reduction would only be half benefit of reducing the mass from the crank and a fraction of what you would gain from lightening the flywheel due to the bigger arc it will go through.
The FFF has a lot less mass in it (with the Simplex we are talking kilos)
Are you saying the bucket followers weigh less than the moving part of a finger follower ?
Also , seeing as the camshafts are moving at half engine speed then any weight reduction would only be half benefit of reducing the mass from the crank and a fraction of what you would gain from lightening the flywheel due to the bigger arc it will go through.
I'm saying the FFF apparently weighs less than a normal head (well, that's what I'm told). I know the original question was about rotational mass, but I can't see how drilled out buckets with their gubbins would add weight compared to the original stuff. I'm more than happy to be shown otherwise - I'm never too old to learn something!
I tend to agree that a Duplex is probably safer than a Simplex but with modern methods of production and materials I would chance my luck with a Simplex. Given though that I put a super light flywheel in with a smaller 7 1/2" clutch the benefit was that this was not an engine out and oh you do notice the difference. Can't do the maths to prove it but it makes a difference, notice it more in low gears. Yes it is a bit tricky to launch but it's worth it. Went for an MOT, the inspector stalled it five times and said "please put it on the ramp"... Chuckle
Don't get confused between rotating masses and static ones.
J
Don't get confused between rotating masses and static ones.
J
Superlight and 7 1/2 single billet twin plate from Super Clutch. I modified the bell housing as well but this just to get a different release bearing in.
Tried sintered plates but they don't last so long... now have organics without springs. Can get reverse without doing the fifth gear shuffle. Changes gear quick as well, less inertia in the plates so syncros don't work so hard.
I'm nuts..... this is a road car, never been tracked or going to
J
Tried sintered plates but they don't last so long... now have organics without springs. Can get reverse without doing the fifth gear shuffle. Changes gear quick as well, less inertia in the plates so syncros don't work so hard.
I'm nuts..... this is a road car, never been tracked or going to
J
Don1 said:
It's more about the mechanics of what is happening in the engine, rather than the amount of pies eaten...
RG say that it takes a huge amount of weight out of the engine. All I can say is that my engine is so much smoother with it in (but this was with the FFF and Syvecs as well).
am i missing something here, i thought AM said the finger followers were much less friction/ heat transfer than buckets so freer revingRG say that it takes a huge amount of weight out of the engine. All I can say is that my engine is so much smoother with it in (but this was with the FFF and Syvecs as well).
Now RG are saying this is not the case
.
Walford said:
am i missing something here, i thought AM said the finger followers were much less friction/ heat transfer than buckets so freer reving
Now RG are saying this is not the case
.
Well, we're off topic, but I have no idea about that - I do know that all the tappets are out of it, so that would be less moving parts? All I know is that the car revs far faster than it used to do so - if this is the head, the Simplex or the flywheel, or a combination of these, I have no idea. Now RG are saying this is not the case
.
There's plenty on line about it if you want to go and have a read...
It is not only about the weight of the chain with the RG simplex kit, the half time bearing on the speed six is a weakness. It has only a ball bearing that is only splash fed whereas the RG kit uses superior needle roller bearings that also have a pressurised oil feed. My budget might not stretch to a 3F head when my inevitable rebuild raises its head but the simplex will be a must.
Cheers J.
Cheers J.
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