JowettTalk

http://www.brdevelopments.com

LAMBDA LINK £85.00



Oxygen Sensors (Lambda Probes) are self generating sensors that produce a small output voltage according to that oxygen content of the exhaust gas

Higher amounts of exhaust oxygen indicate a lean mixture and produce a small output voltage. Rich mixture produces very little oxygen and the output voltage is higher. This voltage range is amplified and scaled by the display unit to drive an LED bar-graph calibrated to both air/fuel ratio and carbon monoxide (CO). Instant O2 Display Check engine fuel mixture Carburetted or EFI engines Factory or after market sensor Optimise Power And Economy Running lean or rich? That is the question. LambdaLink allows you to monitor your O2 and fuel mixture with ease. Comes complete with a tailpipe kit for accurate readings. A must for the enthusiast.



KNOCK LINK £85.00

Most modern engines will already have a knock sensor fitted as standard, but any type of knock sensor may be fitted as required. The sensor is normally screwed into a boss on the engine block although some manufactures fit the sensor in the inlet manifold. In either case, the sensor must be in such a position that block variations are coupled to the sensor. Assuming the engine is operating correctly, the LED’s will show only background noise which will rise in proportion to engine power output. Any abrupt rise in signal level at any time is an indication that detonation is occurring. The immediate remedy is to close the throttle. Severe detonation will destroy any engine in seconds. Knocking is the self detonation of the unburnt fuel in the combustion chamber toward the end of combustion. The flame burns around ten times faster than normal causing high pressures. Possible cures for knocking are: cooler intake air: increased intake humidity; reduce load; increase RPM; enrich or lean engine from lambda stochiometric; improve spark; increase octane level of fuel; reduce total ignition advance etc.

Monitor engine "noise"
Optimise advance
Detect detonation
Mechanical or Electrical Ignition
Toolbox tool or permanent fit
The Knock Sensor in many cars is quite often a sophisticated microphone. These can with engine modifications prove to be unreliable , this is where the KNOCK LINK comes into its own. Being able to isolate abrupt rise in signal level allows one to prevent the damage knocking causes. Keep a finger on your upgrades. Your Knock LINK will not only allow a safer upgrade path but also prevent destruction of an engine that comes as result of knocking or pinging.

Some points to note re dizzy models...
In most cases the dizzy and the vac advance are to separate part numbers.
Tale Av delco for example...
There are nearly 1000 model dizzys for the SB chevy all with different curves..
Then there are another several 100 models of Xac canisters.
The car manufactors then take a particular dizzy rhen match a Vac adv to to that dizzy ro siut diff fuels and models of vechile...hence a particular Dizzy set can have 1000s of combinations, to best suit if it is a van, estate, truck, car, heavt, liight, performance, family car, engine size/model etc etc.

So the 1st concept to drop is the old idea a paricular dizzy has interchangable curves between manudactures and models for optimin performance.
To clear up any confusion in ou7r application
"performance." is best defined as

It is not all about power; but also about effecient burning and reducing polution

.

effecient burning

gives good econimy by producing max use of potentual energy (power) at a given RPM and therefore reduced emissions.

To establish the Cent we need to get beat powr/emissions at a paricular rpm... We dont all have a Dyno in the workshop so have to do it the hard way...Dyno time is expensive.
Lock down the dizzy weights so the is no curve...this canbe be done with tieing in with wire or very heavy springs.
remove/disable the vac advance canister.
Set the dizzy to a known advance at a given rpm
ie 2500 rpm and 10*
Find a long steep hill make 2 points
Hit these point at the known setting and time
Repeat for a range from 500 rpm thru to 4000 rpm in 500 rpm increments
Change the dizzy advance and repeat...
Graph up the resaults from this using the best times a best performace graph canbe established....
Also put a manifold vac gauge in the car... the max vac curve serves as a ssecondary check that u are on the right track.

Another parameter, if u have one, is a portable exhaust anyliser hooked up in car and note the emissions at each piont.

U may very well find the best curve could also cause ping...do not go above a faint ping. This is the ping curve.
If this is the case ,As I mentioned way back, reducing back 3*to 4* off the ping curve should give enough safty margin to have a curve that is far enough back so there is no ping be it audiable or not.



Generally there is not enough advance in the dizzy to run std idle advance.
Do not be suprised if the std idle avance is say 5* and u now have 12 or 15 *..This now causes heavy load on starter motors and hard starting if excessive depending on the engine design (cam/compession/etc)

This canbe fixed 2 ways
1/with vac advance taken off manifold vac and this depends on the opitum vac advance curve
2/Getting out files and nodding the amount of weight throw out distance of the cent advance mechanism...I may also mean changing the cam shape on the weights to achieve this.

With all this done u are now ready to play with different spings to put the opitum curve into the dizzy...This is best done in car rather than a Dizzy machine...the dizzy machine is easier but dosent take into a/c the small tolerances in the cam gear, flex and other 'in engine' variables.
Any way, like the dyno, I doubt if most of use have a Dizzy macine in the workshop...

Once all of this is done one can establish the Vac advance curve.
Since the function of the vac advance is to provide good emissions and economy at off cruise and cruise (from little throttle to 1/4 or 1/3 throttle) and it works on engine vac...the whole exersise on the hill is done again on the flat.
U need full vac advance at highway cruise speed which has a lower engine vac than at lower around town cruise.
Again using the fixed weights in the dizzy and advancing up to find the ping curve at a given rpm, noting the manifold vac reading.
knock this curve back 3* to 4 * and u will now have a TOTAL cruise/ off cruise graphs. Minus the Cenrifical curve and this will be the amount of advance at a given vac of the engine that is to be in the Vac Advance canister.
The degs u end up with the vac advance is not as critical as the centrifical curve, 2 to 5*s each way is ok....dont go overboard u will be wasying your time The vac it works at is.

By closing and opening the distance the arm moves in the slot establishes the degs in in the canister
By changing to postion of the above changes the vac range it works at
U will need a canister that has a operational vac range within the ball park of the graph.
I Then lengthen the arm slot ( chances are to adapt to moern fuel this will be the case) then once I have a movable distance in the req'd vac range, I make up a couple of little adjustable cam stops Tap a hole each end of the arm and attach the cam stops with screws. Now change the length of these so u end up with the required vac and * deg range.

I then (optional) put 3 or 4 little rounded grooves beside the the point that u wish to use, at slightly different depths. Once u have the dizzy runing on the road u may find u wish to fine tune a little over the next yr to real practical application...or u may change a carb or rebuild it, fix a manifold leak, change a cam, change carb jetting...anything that may change the vac of the engine...or find u get a little ping under certain cirumstances.
These optional settings on the stops makes life eaier down the road.
3 opition grooves at each end of the slot will give u 9 opitional settings.

When u put a dizzy into a dyno shop they just opitmise the dizzy u have in the engine this costs 50 or $100s...
If u want them to estabilsh an opitmal curve then recurve, the time machining is huge, u will then run into a bill of many 100s of dollars....get up to a $1000+ could be expected....be warned.

Ok you do it your way,i do it my and Jowetts way having the best off all worlds.
I will go on with the practical procedure of tuning and setting up of the jav jup engine starting with the dist procedure cenrf start intermediates with vac adv starting and ending % in hg and totals.
with the tests along the way.
I still wait for the standard practical procedure if in fact it is known by SOME of which i doupt

Yes we can go down the route of lamda and knock senors coolant sensors tps sensors maf sensors etc etc with programed ecu to suit but at the end of the day you longer have a jowett as intended with all the problems and there will many.

What can I say to that, either u are not prepared to share your info with other jowetewrs of u havnt a clue
Refer

http://jowett.net/forum/viewtopic.php?p=1409#1409

Not a bad toy but not so easy for use with jav/jup exhaust setup.
IE 2 sensors should be used , one for each side but with 1&3s manifold going into 2&4s manifold the data for the 2nd carb will not be true?.

PS on the Link Engine Management website the tail pipe attachment is an option.


Bryan

Carbs will not be any good either!

So what would you suggest to check the efficiency of the burn and the proximity to pre-ignition or pinging?

Cheap and cheerfull colour tune to start with.

If you can get your hands on one use a portable 4 gas analiser.
But i do procedure first, but i do not know any thing so i better shut up.

Gentlemen. Many thanks to Keith Clements, (who I think is also Forumadmin?), Pat Lockyer, Keith Andrews and Paul Beaumont, plus others, for all you replies to my simple initial request. I am stunned by the number of answers and have saved them to a Word document and find this is 15 pages long.

Your collective wealth of experience has more than answered my initial question, which was only to try to find out if my two distributors were basically the same unit or not.

There is obviously more than one way to skin a cat, or to set up an engine, and I shall try to use a distillation of all this information to help me. Perhaps we could draw a line under this discussion thread now and please accept my grateful thanks for the collective help give.