Voor wie het interesseert:BRON: UK RX-8 Forumhttp://www.rx8ownersclub.co.uk/forum/viewtopic.php?f=6&t=71320A)
Becaue of the doubts of PeteH and the observations of RenesisRaceBuggy (thanks)........(the latter caused some doubts with me about my own previous testing) today I did a new testing with my Rex and measured engine-, coil mounting plate bracket strud-, mounting plate- without Isolation (and blackened at the measuring spot for correct results).....note: the difference between a galvanised/partly-light corroded bracket and matt blackened measuring spot is over 5 degr. C.) and of course I measured each individual coil.
The results were different as my previous indications and you will find them beyond.
I drove the car hot with sump oil temp. 95 degr. C.
.......stopped and started measuring a couple of times, each time after running the engine at 4.000 rpm idle for 1 minute at least.
This is wat I measured (the engine block temp raised during the testperiod of 1/2 hr from 95 to 105 degr. C.
The galvanised bracket strud
measuring halfway between engine and bracket plate had an approx. 5 degr. C. lower temp. as the engine temp.
The temp of the blackened spot on top of the mounting plate was approx. 10 degr. C. lower
as the engine temp.
The 3 "front coils" were more or less the same in temp, with more or less similar results measuring at 1)..the coil body close to the terminal connector 2)..the coil body just beyond the "tower"on which the ignition leads are connected) ..1 and 2...did not differ significantly.These 3 coils were more or less similar in temp. ...between 75 and 85 degr. C......which is approx. 10 degr. lower as the mounting plate.Coil nr. 4
(closest to the firewall) was generally 5-10 degr. C. higher in temp as the other ones
.......for this coil there is a "gain" by ceramic isolation of the mounting plate of only 5 degr. C. to zero.
The increase of heat at all the measured elements were more or less parallel curves.
The results means for me for the time being (or forever) maintaining of the isolation between coil and mounting plate however for the future if I could find an easy solution for lengthening of the threaded tapends some additional air space between coils and the isolation.
Especially coil nr. 4 needs it.......B)Rudolph wrote:
.........."The results means for me for the time being (or forever) maintaining of the isolation between coil and mounting plate however for the future if I could find an easy solution for lengthening of the threaded tapends some additional air space between coils and the isolation.
Especially coil nr. 4 needs it......"...........
With reference to my in yesterday's post mentioned wish/need for some free air space gap/isolation beyond the coils today I made a additional heat isolation improvement.
I removed /inspected the 4 coils with total 27.000 mls since new.........they made a good impression / as "new".....car runs fine so for this moment no reason for renewal.
To achieve a free space under the coils for better cooling at the bottom I made an 1,5 mm aluminium sheet that is placed on 1 double layer of 3mm ceramic heat insulation tape that was already installed by myself.
The coils now are not placed direct on the ceramic tape any more but have approx. 6 mm free space.
Previously I had 2x a double layer with a total of 6 mm ceramic tape.......I removed 1 layer because I needed sufficient length of the screwthreaded stud to fasten the coils.
On the pictures you can see the set-up consisting of ........1) the mounting plate.....2) one 3mm layer ceramic tape.....3) one layer 1,5 mm aluminium sheet metal....4) 6 mm free space for air ciculation.....5) finally the coil on top of that.
Furthermore I "spreaded" the 4 coils like the spreaded fingers of a hand to enable extra free space for some coolin of the coil.Meting met IR temp meter/pistool (meetbereik tot 1.100 gr. C)