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Triumph TR6 - New Ignition

I switched ignition modules today from a Crane XR-700 to XR-3000. It really seemed that like there was a noticable improvement in acceleration and top end performance, and I guess I'm wanting reassurance it wasn't imagined.

The coil is a Lucas Sports, and the ballast wire is by-passed. The XR-700 is supposed to operate with the resistor in service, but because of the internal resistance of the coil the module never got hot.

The XR-3000 is supposed to be more sophisticated and a "true" high energy ignition, from what I've read. That was part of the reason for the upgrade - spare parts was the other as the sensor for the two is the same.

Anyway - I'm happy with the results. Those considering going to electronic ignition need to by-pass the XR-700 and go straight to the XR-3000. I've never even considered the Pertronix (let the flames begin).

Brent
Brent B

I don't know that flames are in order, it is just a matter of a difference in the systems. The Pertronix is a Hall effect drop in install while the XR-700 is an optical pickup unit that has to be powered. In either case, their primary job is to replace the points and that is just about it. I feel that optical set ups are more fiddly on installation than a Hall effect unit for inside distributor use, crank triggers are another matter. As to Hall effect vs. optical, it is more a matter of personal opinion and/or what is readily available to you.

The XR-3000 sounds like somewhere between doing the point replacement bit only and also going to something like an MSD 6 or 7 series multi-spark box (Crane has their versions of multispark boxes too). It is my understanding that the XR-3000 system has a longer spark duration, but it is one spark cycle as opposed to several in the multi-spark set ups. I can see it contributing to more effective burn at lower RPMS and there being an improvement at starting low and going up the power curve, but I would expect that it probably drops back some at the higher end of the power curve, just like the multi-spark boxes. With the multi-spark boxes, you drop back to single sparks at higher RPMS as the advantage longer spark duration is diminished. However, since you made to the uppper end better, it still feels good throughput the entire overall range.

I don't know if it is true with the XR-3000, but if it is anything like a multi-sparks when it comes to controlling the spark duration, remember to disconnect if you have to do any welding on the car. Otherwise you take a risk on killing the box.
SteveP

Brent
One nice thing about the Pertronix is that it is virtually invisible. It like you guys doin the port and polish along with the shaved head not to forget roller rockers...all invisible.

Charlie you went overboard adding 2 more cylinders:)

Rick C
Rick Crawford

I use the Pertonix to trigger a Jacobs Omni Pack. It made a world of difference. Brent you should see a noticable improvement. The xr-3000 is comparable to the Jacobs.

Derek
DL Harding

OOPS
I meant Chris T.
Sorry Charlie and Chris.
Rick C
Rick Crawford

I am looking to install a pertronix ignition. How do I tell which one to buy ie neg or positive. Another question took the transmission out. Simple question for those that have done this before on this car 72 tr6 are the bolts from bell housing to motor two different sizes some 1/2 inch others 9/16 thanks for info dave
dgf Finch

All TR6s are negative earth/ground, so get a Pertronix for a negative earth/ground car. As for the fasteners, they are a mix of 5/16" UNF (1/2" head, interchangable with 5/16" SAE) and 3/8" UNF (9/16" head, interchangable with 3/8" SAE). The British UN(F{ine} or C{oarse}) standard came out of WW II and all the US Lend Lease equipment to be compatible with the stuff on all of those tanks and planes and such).

Get the TRF "Blue Volume 1" book out and do a fastener count/part number look. You can take the TRF fastener number and translate it into diameter and length using their parts list. They do the size callouts in head size by 1/16" and length callouts in 1/8" increments as was done by the factory, but can only supply in 1/4" increments. As an example, HB810 is a hardware bolt, 1/2" head (5/16" dia) that is 1 1/4" (i.e. 10 eighths) long. An HB912 is 9/16" (3/8" dia) that is 1 1/2" long. If you try to get an HB809 or HB911 for example, it should automatically bump up to the next 1/4" increment. Buy good stuff when it comes to hardware.

If you really want to get exact on the grip lengths and fastener lenghts, you will have to go the AN/MS route of mil-standard stuff. For this particular application, I would say that would be overkill.
SteveP

Hi DJF

The only point Steve forgot is there are a way too many and all require too many turns...:)
If you have forgotten and want exact placement for and aft. Mine is on stand intact? Let me know.
Bill
Bill Brayford

Bill Thanks I was thinking of using stainless any thoughts Also talking about the bolts not the studs why do you suppose they are different sizes. I understand about the two many turns, told my son it would only take a half hour to pully tranny, he quit second son helped and quit finished the job with my trusty daughter dave
dgf Finch

Dave
Sounds like your daughter is the only one who gets to drive it when done. If your rich, go for stainless otherwise, save your money for something that is visable.
Different lengths...what was on the shelf that day.
Rick C
Rick Crawford

Well, I guess since this has gone off topic and morphed into a semi-new one, might as well stay on that for a little while. The too many turns part with fine thread fasteners doesn't really bother me most of the time. The advantage of the fine threads is that you have a fastening system that is less susceptible to vibratory loosening. It is also why I feel that air and an air ratchet are really nice to have items. Maybe this is why they don't bother me most of the time. If you are going to be doing a lot of wrenching, it pays in time saved to get yourself a small compressor, a 1/2 impact wrench, a 3/8" air ratchet and a 1/4" air ratchet. Since you will be doing this as a hobby and not feeding the family from it, you don't have to spend tons of money to get high end air tools. Those three tools at Northern Tools would run you anywhere from about $120 to $200 depending on which specific brands or models are selected. A set of ratcheting box end wrenchs also comes in handy when doing things like removing the windscreen.

As for use of "stainless" (I prefer to think of it as corrosion resistant steel or CRES), if you go that route, make sure you know what you are getting. You will want fasteners made from one of the precipitation hardenable alloys (13-8PH for example) and not from one of the work hardenable 18-8 family of austenitic alloys. The other down side of CRES is that it is more prone to galling so use of an anti-sieze paste should be considered mandatory. Personal opinion is that this is overkill for your stated application. For the vast majority of the fastener applications on these cars, you are just as well off using a good quality cadmium plated steel fastener. Look in your local phone directory and find a specialty place for fasteners and tools. Every town of any size has at least one. Buy in reasonable bulk (Say 25 each of a few different lengths in a given diameter, 100 nuts, 100 nyloks, 100 flat and 100 lock washers for same) and you save a bundle over typical hardware store prices and will typically get better fasteners to boot.

For those special applications where you want to make sure that there is no shear loading across the threads (say the drive shaft or half shaft flanges), then you should consider going the AN/MS/NAS route of mil spec hardware with specific grip ranges in 1/16" (most of them, there are some exceptions) increments. You can find the AN/MS/NAS stuff at places like Aircraft Spruce, Pegasus Racing, local aviation supply houses at general aviation fields, specialty surplus houses, etc. This stuff will typically run about 2 to 4X the price of the fastners above (except at the surplus houses, I've found some deals before at one here in Marietta). Here, the purchases are typically made much closer to actual need as opposed to trying to keep a good stock of fasteners on hand.
SteveP

This thread was discussed between 21/02/2004 and 19/03/2004

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