GP2.5
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Posts posted by GP2.5
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Mr Speedy,
The cylinder head on my .69 PI is a realy good casting compared to a "spare" 2500 head that I have - terrible coreshift, I asume it will flow less than the 69 PI head. Relaying on eyesight to judge the flow is often totaly unrealiable. Exhaust ports are very unintuetive. Even a flow bench is not always dead on correct. there is nothing like a steady flow in a running engine.
Gunnar
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Hello,
That figure is for a straight pipe, the actual iayout of the exhaust system is just - or more- important than just focusing om the diameter. One car maker that I know off noted that a 2" OD system started to get restictive at 135 HP, When they won EM.1963 - If I remember corectly,their cars had 60 mm exhaust. A six cylinder flows it,s exhaust more steady so it might not directely correspond.
Gunnar
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Hoffman,
Triple Y-headers is one way to try to overcome a 90 degree comfort crank. if you want a real racing engine single plane is the only option.. Chrysler did some extensive testing and production of engines with Tri y headers, 1962-64 Max Wedge 413/426. A good friend of mine have a Dodge 1963 with a 413 Scary!
But at present we are far off from the topic of a decent exhaust manifold for a Vitesse.
My own wondering is, will a 6-3-1 of a good design always outperform a good 6-2-1 exhaust manifold? Will it give a wider power band, higher top end power or both?
Gunnar.
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Hello John and Hoffman,
Yes simple and effective exhaust is one of the reasons for going flat crank on a V8 ment for racing - from the very start, just as Cosworth, Ferrari Lotus and more. And of course the sound, and the compact light crank, and the lower build. I guess the Le Mans Ford GT 40 gave its best around 6000-7000 rpm. Anyhow the across plumbing gave an aledged 6% power increase over other systems and a power band with hardly any flatspots. Pulled away from the Ferraris after every corner.
Very nice headers indeed. Did you listen to the hakosuka?
Gunnar
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Just for your ears, visit Y-tube 1971Nissan skyline gt-r "hakosuka" Well tuned exhaust - six cylinder love.
Gunnar
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Sorry about the empty space above, but the intention was to "glue in" a photo of the exhaust system of the Ford GT 40. Advanced plumbing across to overcome the 90 degree crank of the Ford V8
Later in the seventies Ford had a crate 302 with a flat crank 180 degrees. And just recently the new Shelby has the same. A 90 degree V8 will always need a crossover exhaust to give the last ponies.
Gunnar
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Yes, John, petroleum industri is always testing so is the car industri just as your Minestery Of Transport.
My simple test was just filling upp two E- Containers with 3 dl of petrol and let it evaporate in the shed. I did this several years ago when I had an Alfa with Dellortos. they clogged upp during the winter when the petrol evaporated. After 3 winters they gave a lean mixture, very hard to start and spitting back - and was almost impossible to clen out. Sticking shellack like depostit on the jets that would not solve in petrol. Idle/lowspeed jets really clogged. Aceton and a US Ford carburettor cleaning solvet was the best I faund for dissolving.
This agony with petrol leaving deposits when evaporating began when the petrol industri started to hard crack the crude oil.. I will do the same simple test with a new petrol just launched in Sweden, it,s partly syntetic about 20% of it,s content comes from processed pine oil. I have heard good about the German Aral petrol -104 octane - its also partly syntetic. I think Germany is the only place you could have it -out of reach for us.
I think your problem is deposits after evaporation and the drying, no lube, rubber destroying ethanol.
Gunnar
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Well, You would only need one 5 litre container for a car resting over the vinter. I have tested to evaporate ordinary 98 octane and alkylat fuel, 98 octane blures a glas bowl. When evaporated with alkylat there is no blure on the surface of the glas. Fuel with etanol will keep water in suspension, fuel without will keep almost no water in suspension. When testing fuel directly from a filling station for water the result is in 19 cases out of 20 nil. and that goes for England as well.
Gunnar
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Hello,
Before layup run the engine with alkylat petrol, the purest and most stable fuel you can get. I assume that the Briggs and Straton fuel is an alkylat. I have two cars with mec-injection and they rest the winter out with alkylat fuel in thier venes. Also a cog wheel pump - just as the original Lucas - is not as sensative to clogging as the Bosch pumps are, an alternative to Bosch is a Pierburg, a cog wheel pump superior to all Bosch pumps.
Gunnar.
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Hello Alan
Looks great! I am running without the mesh, with a camfered inlet pipe. Placed a superstrong Neodymium cup magnet on the outside of the sump close to the pump inlet, traps everything.
Gunnar
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Hello Alan and 2.5piman,
Yes thats normal, but if that extra volume of oil gets to large it,s likely to cavitate. Still the type of oil pump used - G-rotor - is not known to cause cavitation, if it occures it will be in the pick-up/feed pipe/inlet or at the relief valve.
Wishbone classics sell a blueprinted TR oil pump, they are showing a diagram over rpm/pressure, Above 5500 engine.rpm the pressure drops, I would say that indicates cavitation. I think GT6Steves solution is the ultimate. But i am quite sure that a better oil-pickup would be a good start with a wet sump oil system.
Gunnar
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Alan Very interesting!
"I had a long discussion several years ago with Smokey Unik about oiling systems, and one of the things that we both agreed upon was the over use of hi-volume oil pumps in stock clearanced motors (it's the first thing the Chevy guys purchase to put in their new motor, whether they need it or not)! The problem lies in the fact that the pump puts out way to much volume for the stock clearances to expell. The extra volume of oil has to go somewhere, so it lifts the relief and, on most pumps (ours included), is dumped back to the inlet side of the pump. This continual recyling (the relief will basically never close in this situation) builds unnecessary heat in the oil, as well as creating cavitation which aerates the oil - both things are bad news. Again, do NOT use more oil pump than your engine is designed to use! The Ford engineers knew what they were doing when it came to sizing the pump to the application! Stick with the stock (M19) pump on all but heavily clearanced motors!"
Do you have a H-V oil pump and running stock clearences?
Gunnar
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Dear all,
I would like to know the conditions when measuring engine horse power according to bhp net. I have tryed to google this without luck.
Best regards
Gunnar,
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I was going to suggest checking this option out.........
.........only it doesn't seem to be currently available.
Not appreciated by everyone (!) http://www.triumphexp.com/phorum/read.php?8,1268283,1268283#msg-1268283,though he's biased!
Nick
Hello Nick,
Followed your last link, interesting discussion about the birth of the 6-3-1 manifold. Would like to add that Chrysler did som work on 6-3-1 manifolds in the sixties. More "recent" 1968-82
MATRA used 6-3-1 manifolds on their 3 litre V12, they tryed 6-3-1 and 6-3 -3 exhaust pipes per bank- they also tryed 6-1 and 6-2-1. The final version of that V12 was claimed to have 530 HP+ and it had very beautiful 6-2-1 manifolds.
What is so special with the Triumph six that it needs a 6-3-1 system to devolop it,s best? Or is it so that all others tuning six cylinder engines are ignorent in this respect?
Cheers,
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If the design is marginal, then we would not like to have any sort of axial load or? MB 220/230 never - not that I know of - fails thrust bearings, no fan on the crank.
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Hello fast driver,
Still, compared to other small six cylinder engines that almost never fail their thrust bearings the only major difference is the crank mounted fan on the Triumph engine.
If you put an asortment of the thrust bearings on a table and ask, point out the ones that will fail, it will be a guessing game.
As long as the engine is running it will pull the crank, assume that the horrid original fan absorbs 3 HP at 5000 rpm, is that a minimal force? A full grown man with a bar behind the damper could hardly copy that.
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Dear all,
I use a Spal that fits like a glove behind the radiator of my 2.5PI. It accually almost cover the whole of the radiator core. Same fan is used on the Berlinetta Boxer in a pair. Talking of fans, could the horrid original fan as it is mounted directly on the crank cause some of the thrust bearing concern? Aircraft engines have really sturdy thrust bearings.
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Thanks, - I know that I am off topic - My downpipe is 2X40 mm ID, Y-pipe outlet is 21/8 OD - ie a true 2" inch pipe. I "guess" that it should be at least 21/4" But still this is what I got.
Cheers
Gunner
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Hello Hot Shoe!
Yes very informative indeed, I made my "pick" from that info.
You have the skills! Should I fit a TR5 exhaust manifold with a very decent downpipe to my PI My69 or should I go for the 6-3-1 from Mr Witor? Are we talking about more or less than 5 Hp improvement.
Love to listen to your white PI on the rollers,
Best Regards
Gunner
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Hello all,
As Nick say it,s a gear pump, and it is quiet. It has a huge 16 mm inlet so a step-up adeptor is needed on the intake side, guess that the pre-pump 16 mm fuel hose reduces cavity. Still a larger outlet from the tank would be the best.
To my best knowledge the Pierburg was used on Ferrari 400i with K- jetronic, at the time mine was cheaper than a Bosch 044. You will find it at YOUREX a very well supplied swedish supplier of all sorts of fuel pumps,fans, generators starters etc.
Before the Pierburg I was running a Lucas pump with a Facet pre pump, that worked just perfect untill the Lucas pump started to fail.
I love the Lucas PI, I would never change to ECU injection
Gunner
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Hello Josh,
Flow will drop off a lot when you run a pump at a higher pressure than it was designed for, So what is the number of the pump you are using? Most pumps are designed for 3-4 bars
I run a - quiet -Pierburg E3T pump on My PI . That Pump is designed for a 6.5 bar pressure , the flow is 110 liters at that pressure. So regulating it upp slightly to PI pressiures will still give a graet flow
Almost all Bosch pumps that I know off are running on the edge at Lucas PI pressures
GP
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I have 18 NoS .800 Triumph tappets, i do not exaggerate when I tell you that they are flatter the salt flats. I have checked them under a UNION Metalurgic microsope.
New Diff Oil
in Drivetrain
Posted
A Gear Lubricant GL 4 is suitable for use in a zero to low offset hypoid gear application - gearboxes - High pressures of a high offset hypoid gear demands a GL 5 oil. Best choise is a non sulphor additive oil - no dammage to bronze parts - A GL4+ could be functional. But to be safe use a GL 5 oil.