13/60 engine/exhaust mods..bits wanted
Posted By : William Davies, 26-Feb-2005, 12:48pm
Hi Ian,
I guess that should have read "uprate"...
First question is which engine do you have, GE or GK prefix? The GE is a better starting point as it is more free revving. Twin carbs will give little benefit in terms of bhp (arguably none at all) below 4500rpm, the GK engine starts to strain around 5000rpm. The gain will be in a very small power band, with an often reported loss of torque at lower revs. If you're not careful you wil end up with a less driveable vehicle. The GE engine is better at high revs but the same disadvantages apply at low revs.
I know John Kipping has always favoured a large single carburettor on the 1500 engine. The single carb Toledo and Dolomite 1300 manifold is a better breathing design than the Herald 1300 type, so this in conjunction with a single 1.5" SU may give preferable results over the TC arrangement.
The benefits of the electric cooling fan are also debateable. The usual 13/60 fan is a very light aluminium pressing. While there is an argument that the standard fan is using energy even when not required, this is traded against the electro-mechanical losses of an electric fan. Here the energy is converted from mechanical to electrical at the alternator/dynamo, then converted back to a mechanical action by the fan motor. I don't know which is truly less efficient but I'm sure someone will have done the maths. If you go for an electric fan be sure to have the full width 21" radiator in place first as the fan body will obscure a large proportion of the standard 14" radiator.
Cheers,
Bill.
I guess that should have read "uprate"...
First question is which engine do you have, GE or GK prefix? The GE is a better starting point as it is more free revving. Twin carbs will give little benefit in terms of bhp (arguably none at all) below 4500rpm, the GK engine starts to strain around 5000rpm. The gain will be in a very small power band, with an often reported loss of torque at lower revs. If you're not careful you wil end up with a less driveable vehicle. The GE engine is better at high revs but the same disadvantages apply at low revs.
I know John Kipping has always favoured a large single carburettor on the 1500 engine. The single carb Toledo and Dolomite 1300 manifold is a better breathing design than the Herald 1300 type, so this in conjunction with a single 1.5" SU may give preferable results over the TC arrangement.
The benefits of the electric cooling fan are also debateable. The usual 13/60 fan is a very light aluminium pressing. While there is an argument that the standard fan is using energy even when not required, this is traded against the electro-mechanical losses of an electric fan. Here the energy is converted from mechanical to electrical at the alternator/dynamo, then converted back to a mechanical action by the fan motor. I don't know which is truly less efficient but I'm sure someone will have done the maths. If you go for an electric fan be sure to have the full width 21" radiator in place first as the fan body will obscure a large proportion of the standard 14" radiator.
Cheers,
Bill.
-
13/60 engine/exhaust mods..bits wanted
Posted By : David Rumens, 26-Feb-2005, 05:34pm
Bill, the Toledo inlet manifold have better breathing is a bit of a myth. The smoother running and small increase in low end torque is largely due to the smaller diameter pipes. Not the pipe length. If I remember the 13/60 is around 28mm and the Toledo is 25mm. Above 4000 rpm the power drops off on the Toledo manifold. The main purpose of the smaller pipes was to reduce the CO level at low RPM. Lean burn at low rpm I guess.
Interestingly if you take a close look at the 13/60 manifold the different pipe length is offset by the way they are fed from the carb. The gasses take longer from the Carb to get to the shorter manifold pipes that they do to the longer pipes. In other words there is a built in delay on the shorter pipes. Hope that make sense!
Having tried 1.5 and 1.75 SU,s on both the Toledo and the 13/60 inlet manifolds I found the 13/60 to gives the better overall results. Having said that the twin carb set-up with the right needles and springs out-performed both the single carbs types except for smoothness of tick-over. The secret of maintaining the torque around 2000 rpm with the twin carb set-up is to get the needles & springs right and fit a Spitfire head. Get it wrong and as you say correctly say the engine has to be revved all the time.
In all cases I used the Spit Mk111 Cam which are available from Canley with large journals to fit the Herald engine.
I do agree with your advice regarding tuning a GK engine and the advantage of using the GE. Having in the passed covered some 125,000 miles with a DH engine, which has the same large bearings as the GK, I totally agree it was no match for the earlier GE engine in terms of revs and smoothness.
On the both 1300 & 1500 engines I would use a Spit Mk111 Cam, an extractor manifold feeding a Vitesse Mk11 exhaust system, twin SU's with richer needles and yellow springs. The 1300 engine must use a Spitfire head. I agree as you say there will be some loss of low end torque, but not as must as would be supposed as the right Carb springs will help to off-set this.
If you use the 1500 engine then overdrive is a must and if possible a 3.89 diff. With this engine the increase in power is still at the lower end of the RPM range due to its long stoke and the way to make the set-up work is to change the top gearing to reduce the revs.
Please note this is all for road use and not for track racing where tuning must be treated in a different way.
-
13/60 engine/exhaust mods..bits wanted
Posted By : Ben Ferguson, 27-Feb-2005, 07:47pm
I found that a free flowing exhaust with a tubular manifold and twin 1.5" SU's gave a really good imporvement in power over standard, but only after it recieved new rings. Before, with worn rings there was no difference whatsoever! After its most recent rebuild (due to a spun big end bearing!) I found out that the cylinder head was a mk4 spit one, with unleaded conversion, which meant bigger valves and improved compression ratio. With this set up it gave an indicated 95 on the speedo, so I guess a real world 90 ish maybe, compared to before when it only got 85 on a good day, real world 81?
0-60, once the rings were bedded in, was 12.5 secs, a significant improvement over the 17.7 std!
Currently having grief trying to time in the rather loony fast road cam at the moment, hoping to get it right one day! Flat as a pancake below 2k though, so perhaps wouldnt suggest using this cam (Kent TH5) unless you drive like a youf!
As far as electric fans go, I went cheapo and cobbled one up using a fan from a renault 21, so as not to waste vast amounts of money if it wasnt a suitable mod. Total cost &163;20. With the metal fan removed it does give you a little something extra top end! Top speed went up by about 2 or 3mph (with the coupe hardtop reached the illusive 100 mark once, no following winds, honest!) I dont have a thermostat on mine, I just keep an eye on the gauge, but its certainly handy in town for instant cooling. For B-road thrashing I just leave it switched on, but thats because my rad in tiny and nearly dead!
It must use some power as when you switch it on tickover slows down, but I havent a clue how alternators work so I'l leave that bit of theory to the experts! Just a thought though, the alternator is turning all the time obviously, so how does a greater electricity loading sap power? greater magnetic fields?! I'm curious!
Ben-
13/60 engine/exhaust mods..bits wanted
Posted By : William Davies, 27-Feb-2005, 10:03pm
-
13/60 engine/exhaust mods..bits wanted
Posted By : Chris Taylor, 02-Mar-2005, 06:45pm
Interesting to see how themes crop ug again and again. The old chestnut about overall efficiencies of engine to alternator to fan motor versus direct drive is a complete red herring. The power "saving" (and it's absolutely real; why do virtually all current cars have electric fans, and the rest have viscous couplings which do a similar job?) is not because the mechanical fan is inefficient and the electrical one more efficient, but simply because the mechanical fan is being powered ALL the time.
The drain on the engine increases with engine speed (it's doing more work by pumping more air) so the direct drive fan is not really well matched to its task. It barely passes enough air for cooling at tickover, but pumps far more air than needed at high speed, and it pumps air whether the cooling is needed or not. A viscous coupled fan is better, but the thermostatic electric fan is better still as it runs at high speed and pumps effectively when it does, but only runs when cooling air is actually needed. The only down side is that of shielding some of the radiator core from natural air flow as mentioned by some above. I ran my Herald for some time with no fan at all and never had any overheating at speed, only a bit warm in traffic. Fitting "shields" each side of the radiator to "funnel" air through all the radiator rather than round it (like on the Spitfire) was an improvement.
Although arguably if an electric fan cut in when you were accelerating hard, you would not get any more power at that point in time, you get the benefit in fuel economy much more of the time, as well as the extra 3bhp at higher revs for MOST of the time.
I'm surprised no-one has mentioned the other GREAT benefit of an electric fan; until you try it you won't realise just how much NOISE the standard fan makes at speed!
Mention of other tuning mods, I'm not sure you will get full benefit from twin carbs unless you fit a better cam. Spitfire Mk3 profile is probably the one to go for for road-going. A small but useful boost is also available from a big valve head. Late Toledo and late Spit Mk4 heads had larger inlet valves BUT NOT ALL Mk4's I think, but while the Spit head has 9:1 compression, the Toledo has 8.5:1. Not quite max power, but possibly a better bet for lead free fuel, (What you lose by lower compression you gain by more ignition advance perhaps?) Not sure how you identify these heads from the outside but no doubt someone can identify the parts numbers.-
13/60 engine/exhaust mods..bits wanted
Posted By : Ben Ferguson, 03-Mar-2005, 00:06am
Yes the noise!!! forgotten about that! much better without
-
13/60 engine/exhaust mods..bits wanted
Posted By : Colin Wake, 03-Mar-2005, 10:25am
I thought the reason most current cars had electric fans is because most current cars have transverse engines but still have the radiator at the front, so an engine mounted fan would be useless.
But perhaps not.
Colin
-
13/60 engine/exhaust mods..bits wanted
Posted By : Tim Everitt, 03-Mar-2005, 01:19pm
errrmmm...both my Chimaera and Merc have electic fans and they're not transverse engines.. Incidentally, they both have TWO electric fans.-
13/60 engine/exhaust mods..bits wanted
Posted By : Colin Wake, 03-Mar-2005, 09:32pm
We can't all afford to have fleets of TVR's and Mercs!! Unlike some obviously!
When I said 'most' I meant Fiestas and Focus's etc.
Colin-
13/60 engine/exhaust mods..bits wanted
Posted By : David Rumens, 04-Mar-2005, 08:13am
Colin I agree, include VW and most mass produced cars.
I guess in these days of engine mangement systems and tighter controls on the CO levels the electric fan makes an easier way of controlling the temperature.
Also the modern approach is to use much larger raidators the in our cars, this reduces the number of times the fan switches in.
The case for an electric fan increasing the top speed or reducing the 0 to 60 is a bit of a academic. But its still worth considering for the other reasons.
-
13/60 engine/exhaust mods..bits wanted
Posted By : William Davies, 04-Mar-2005, 08:56am
Having recently changed the clutch on our 1993 VW Passat (never again!) I have learnt far more about this car than I ever wanted to. I was intrigued to find that the electric fan has 2 speeds. The radiator switch is set to come on at 95 degrees C, with high speed at 105 degrees C.
Cheers,
Bill.
-
13/60 engine/exhaust mods..bits wanted
Posted By : David Rumens, 04-Mar-2005, 03:43pm
Thanks Bill, Hmm - its clever stuff these days.
I guess the next thing will be a constantly variable speed cooling fan or maybe variable between lower and upper speeds.
The clutch sounds like a nice job!
-
-
-
-
-
13/60 engine/exhaust mods..bits wanted
Posted By : David Rumens, 03-Mar-2005, 06:17pm
Colin, I suspect you are right.
I reckon the other reasons are a cut in warm up time and who needs a fan cooling the engine in the winter.
I have kept the standard fan as I like to keep things simple!
-
13/60 engine/exhaust mods..bits wanted
Posted By : Paul Bodiam, 04-Mar-2005, 05:25pm
Dave Rumens wrote:
..."I reckon the other reasons are a cut in warm up time ..."
I have never understood this claim for electric fans. Assuming that the engine thermostat is fitted and functioning correctly, warm warter will not enter the rediator until the engine has reached the optimum working temperature, so how does it make any difference to warm-up time whether or not the fan is running before the thermostat opens?
Paul-
13/60 engine/exhaust mods..bits wanted
Posted By : David Rumens, 04-Mar-2005, 06:11pm
The fan will create air movement in the engine bay. In this case it creates unwanted cold air movement around the engine. It is cooling the engine directly hence the longer warm up time.
-
13/60 engine/exhaust mods..bits wanted
Posted By : Stephen Cooper, 06-Mar-2005, 00:53am
" fan creates air movement in the engine bay" I find this abit far fetched myself as the engine bay is most probably a windy place anyhow. Anyone who is desperate for power, remove engine fan tho, and use an electric fan which is manually operated. Anybody know about ally rads that fit in a spit?-
13/60 engine/exhaust mods..bits wanted
Posted By : David Rumens, 06-Mar-2005, 10:31am
I fully understand your comments but the fan does add to the existing air flow. That's what it is there for. Before the electric fan came into popular use those involve with cars as a hobby would remove the fan in the winter to aid warm up and running temp. This knowledge has been lost over the years.
The other point to consider with regard to the fan is the theromstat is just not that good at controlling the temp so any reduction in the cooling air is an advantage.
An ally rad saves weight and should improve the cooling if designed correctly.
-
-
-
-
-
-
-
-
13/60 engine/exhaust mods..bits wanted
Posted By : Nigel Gibbins, 28-Feb-2005, 08:27am
Ben,
You've probably worked this out already but - no guts below 2000k is as good as it gets with a TH5 cam -
-
13/60 engine/exhaust mods...Cam woes
Posted By : Ben Ferguson, 28-Feb-2005, 10:55am
Hehe, yes I have NiG even when its timed in accurately I dont suppose I'l see an
improvement there! Strangely the car felt like it had a lot more get up and go when the engine was rebuilt with this cam when I was
initally "running it in" I found I could overtake stuff with some fair acceleration in top gear. Now it feels like the performance has
tailed right off, back to near std cam performance, but less low down and a tiny bit more up top. Checked the cam timing and it was a
fair bit out (dont know why!) so I advanced it back to its normal 103 deg atdc and it now goes pants! smoother though. Any ideas?
Havent done a compression check yet.
Cheers, Ben-
13/60 engine/exhaust mods...Cam woes
Posted By : James Carruthers, 28-Feb-2005, 01:21pm
The graphs I've seen show that the TH5 with an improved head and properly tuned carbs it shouldn't be any worse than a standard engine between about 1.5k and 2.5k... it's all relative...
Who drives under 2k anyway? Ben doesnt drive below 5k on all accounts
-
13/60 engine/exhaust mods...Cam woes
Posted By : Nigel Gibbins, 28-Feb-2005, 02:12pm
If the cam wasn't lubed properly then it may have 'destroyed' itself. Take the rocker cover off and watch the pushrods - check them all for full movement. As for it 'slipping' from it's correct timing... if you have a vernier wheel then its wasn't tight enough, if not then I would suggest the actual timing itself was incorrect. Timing chain wear could casue it to slacken slightly and that would also affect the timing.
Other thoughts are the carbs... you may need to 'tweak' the settings again. Or, if the engine is new the bores may have glazed if the engine wasn't run in properly... how did you do that?-
13/60 engine/exhaust mods...Power woes
Posted By : Ben Ferguson, 28-Feb-2005, 07:19pm
Hmm I did lube it generously but if you remember at the time it refused to start, with lots of tuning on the starter, not good for a new cam I hear! Just bought a dial gauge so will check valve lift when I get chance. No vernier wheel, but when I fitted the timing chain it was new with virtually no slack, now its past the max desireable (10mm) only 5k miles on, suggesting either worn chain wheels or stretching due to overloading?? Tried to reset ignition timing today back to factory settings to get something to work from, but problems with the coil have started again, getting more of a spark from the + and - terminals to the ht output terminal than at the points, so now it wont start!
As for bore wear, took the plug out and shone one of those nifty little led torches down the hole, rebore markings still there, so no glazing at least. Asked machine shop to check the cyl head for valve leaks when it went to be skimmed and have a new vlave fitted, whether they did it or not I dont know but they said it was ok! So hopefully compression is ok.
Carbs arent set up too well, hard to judge mixture because the lifting the piston and listening for increase/decrease in revs method has stopped working it seems, whatever I do the idle drops a lot, and the mixture normally ends up rich and fouling the plugs, so wrong needles maybe? AAT, same ones I had in with std cam.
Bewildered
Ben
-
-
-
-
13/60 engine/exhaust mods..bits wanted
Posted By : Duncan Banks, 01-Mar-2005, 00:35am
Back to the fan, in a spitty 1500 we have a full width 3 core rad with a thermostat boss soldered in to take standard fiesta type stats giving a choice of switch on switch off temps as many cars use the same thread size. This turns on a fan mounted on the front of the rad found lying in a pile of junk, it takes up a third of the rad and was OE on something.(not Kenlowe etc). Works fine.
As far as using electrical power, the fan dose'nt often come on until you slow down so the draw of current dose'nt come when booting it, so it won't affect acceleration.
Dunc
-
-
-
13/60 engine/exhaust mods..bits wanted
Posted By : James Carruthers, 26-Feb-2005, 11:21pm
I worked out the maths on the mechanical fan versus the electric - electric takes up something like 1bhp or so. A mechanical fan is something like 3-4?
It also has the other advantages of turning off when not needed - releasing more power.
Best place to mount it is of course behind the radiator - is there more space to move the rad forward in a Herald than a Spit? It can be done either way...
-
13/60 engine/exhaust mods..bits wanted
Posted By : David Rumens, 27-Feb-2005, 07:55am
James, did you take into account the electrical to mechanical conversion i.e. The power is taken from the engine and is turned into electrical power by the generator and then turned back into mechanical power by the fan motor. Where as the standard fan has none of these conversion losses.
On past experience result of both conversions together will have an efficience of around 30% at the best. So any BHP gain when the electrical fan is running will be lost.
The other point is when the engine is being worked hard it heats up more and the electrical fan then switches in. So just when you need those extra BHP there just not there.
The two main advantages with the electric fan are faster warm up and a very small gain in power if you are not driving hard. To me the former is the most beneficial as it improve MPG, reduces engine wear and cuts the heater warm up time.
Just the thoughts of an old engineer.
-
13/60 engine/exhaust mods..bits wanted
Posted By : James Carruthers, 27-Feb-2005, 01:30pm
Dave,
The figure that I found was that to produce 25A takes up 1bhp with a modern alternator.
Now considering the entire electrical load on one of our old cars is so low - even if it totals 50A (standard alternator is 26?) - thats only 2bhp - which is less than a mechanical fan.
I'm not sure how much this has to do with the better design of modern electrical fans... I know the mechanical one on my Spitfire looks very different to a modern electric...
As for it heating up when you drive hard - surely driving on the motorway and fast a-road driving benefits from this - as the fan will switch off due to the air flow... anybody know what speed of air is enough to cool a rad on its own - about 40mph+?
James
-
13/60 engine/exhaust mods..bits wanted
Posted By : David Rumens, 27-Feb-2005, 02:44pm
The conversion factors are largely unchanged on a modern set-up so the pure fact that the energy has to go through a number of convertions will introduce unwanted loss. The other loss I did not cover is the energy in and out of the battery all these areas must be fully considered. The loss is the important factor as we are not dealing with 100% conversion therefore there is a trade off.
It is very doubtful on an average day the through-put of air will provide enough cooling on its own if you are pushing the engine hard, in order words the fan would come on. The exception would be a cold winter day.
However, if you are cruising in overdrive at half throttle on a motorway then yes I agree the airflow would provide enough cooling and the fan would be off.
-
13/60 engine/exhaust mods..bits wanted
Posted By : Stephen Cooper, 27-Feb-2005, 07:53pm
Just a quick point, would there be much of a cut in warm up time by using an electric fan? As surely the thermostat would ensure the only water circulating during warm up period would be the water in block..
-
-
-
-
13/60 engine/exhaust mods..bits wanted
Posted By : Ian Thomas, 27-Feb-2005, 06:11am
opps,not so simple is it!!!thanks everyone for your thoughts....trying to aim at a top speed of 100 mph and bring down 0 to 60 by about 5 secs...is
this unrealistic? fed up with midget out accelerating me so must do something other than buy a 2 litre engine...ian
-
13/60 engine/exhaust mods..bits wanted
Posted By : David Rumens, 27-Feb-2005, 08:02am
Ian, A sensibly tuned 1500 in a saloon or convertible should give the lower to mid 90 MPH and maybe just 100 MPH with a good wind behind you! But it will not have the torque of the 2 litre. The reduction in 0 to 60 is possible.