Hi All, I'm ordering the Reproduction HEI Dist. from TA Perf. and I'm curious, do I need to change the recommended spark plug gap when switching to this distributor? I've been searching the forum but I'm not sure yet. Also does anyone have any good recommendations on new plug wires to get, I might as well upgrade those too since I'll need to change out the old school stock ones. Thanks for any help you can provide!
I don't see a reason to change gap on plugs. But you may want to read Larry's timing thread before you install that hei. And you will need to remove resistance wire to distributer. Hei needs 12 volts not the 7 volts points ignition run
http://everyday-performance.com/distributors.htm You can look into a distributer rebuild. http://www.v8buick.com/index.php?threads/power-timing-your-buick-v8.63475/
Thanks for the replies so far. I'll think on the gap size. From my reading some people say it runs better, others say it doesn't do anything at all. I've been through a good chunk of Larry's timing thread and I'm definitely taking notes
.045 is a safe gap for a GM HEI. There are no downsides to doing so. GM used gaps as big as .060 with the HEI, but you need a spark plug that was made to be gapped that big. It has a longer ground electrode. AC plugs had the suffix TSX as part of the plug part number, as in R45TSX. The NGK plugs for our Buick engines are the UR-4 or UR-5. The UR-45 or UR-55 are the same plugs that you can gap larger. NGK says you can open or close a gap .008 from what it comes gapped at from the factory. The ground electrode should be perpendicular to the center electrode hence the part numbers for plugs meant to be gapped larger. http://www.jegs.com/i/ACDelco/065/R...6&cadevice=c&gclid=COuY2K3YrtMCFdtXDQoduC4FsA http://www.jegs.com/i/NGK-Spark-Plu...2&cadevice=c&gclid=CMD0npnYrtMCFZCFswodPjABhw
Wow thanks Larry! I appreciate the good info. For my final question, does anyone have any recommendations on plug wires? In the past I've just used whatever generic brand. But since the cap style is changing from my stock cap, I'll be changing the wires too.
You will have to change the wires,as the factory wires for the stock distributor are different then the Hei ..As to the gap,I use a loose 0.40 gap or a tight 0.45 gap on bot5h my GS or my race car.Bruno.
I use the MSD Super Conductor Universal wire set. You cut each wire to length and put on the distributor ends. That way, it is perfect. Kit comes with distributor contacts and boots for Point caps and HEI. You install the ends you need. https://www.msdperformance.com/prod...iversal_super_conductor_wire_sets/parts/31193 https://www.summitracing.com/parts/...msd-ignition&gclid=COv6gdeusdMCFd6LswodUy8Czg
The set I use and they are really nice is the Taylor 8mm Spiro Pro wires Part No. 74204. They have a 135* boot at the plug and they are fat enough to grab onto when you have to pull them off to change out the plugs. The angle on the boot makes it easy to miss the other plug and they are not too long. The fit is good and they are made in USA. Well they were back in 2002 when I bought them. I just realized that they are that old but seem to be working good. time cruises when you are having fun. I have used the UR5 NGK plug and now I use the YR5 NGK plug for the nitrous use. This plug is Not an extended tip and is more like the stock plug from the 1970 engine. Works very well with just running the motor too, my compression is at 10.5 I run my timing at 32* total for my engine. They have them at Summit Racing for 55.00$
Stock gap IIRC was as big as 60 thou for HEI cars, and it worked well for me with R45TSX AC Delco plugs. I thought it was a bit big, so I switched to a plug with a smaller gap at 50 thou, and my car ran a tad worse. It may just be my low compression, or my cam or whatever, but my engine liked the 60 thou. Experiment a little, every engine is different.
