Hi Guys, Advice please on what spark plugs I should get for my speedster . I have a Fronty R head to fit and any help will be much appreciated.
Try the same plugs from a Model A ford form the current part houses
Thanks Mark, I was beginning to wonder if there was anyone out there!
There are some of us here but not necessarily with the best answer to your question. I was rather waiting for a response identifying era type plugs. I've never used whatever is considered correct although I knew Model A plugs would fit. My choice was to get the plug adapters and experiment with modern plugs until I found something good. My initial setup was way to rich due to a carb that could only be adjusted by changing the jets and finding jets for a Zenith HP5A was a bit of a challenge. Since I got a good jet match, finding a modern plug for my engine was pretty easy.
If the Model A plugs aren't satisfactory, consider the adapters and modern plugs unless you get better answers before hand.
Not an experience with a Fronty head but on our roof head we had some modern plugs, not sure of the model but it didn't run particularly well, not picking up at low RPMs and missing when idling.
After some advice we switched to a set of NPK BP2ES, and the difference was profound. Consistent power through the rpm range and starts up with ease now.
Believe that the reason was that it was a stronger spark more suited to the high compressions of the OHV. Hope this helps.
Thanks for your advice Walt and Joe. I shall go with all of it so -- here's hoping!
I've a Fronty T model come in recently for a full service and it is sporting a set of Motocraft
TT 15 plugs. I've not heard it run on these so "the jury is still out".
I did a Fronty with the 18mm adapters and while the head was off I had a set of plugs from a Ford Escort that I ran in and liked where they landed. I put them in and it started and ran really well. My Fronty's don't have the adapters and I run the Model A plugs and they don't start as easy...I really should order up the adapters and change them out.
I am going to add my uneducated 2 cents. Depending on how far up in the well the plugs end you could try a set of 7/8 long body plugs. This is what was used in the early Chevrolet valve in head.
You might try Autolite 3076 (These might be the plugs used in Model A's)
While there are different heat range plugs in the 7/8 - 18 size, it's finding them. Most all the Model A parts suppliers should carry 7/8 to 14mm adapters so you can try different plugs. I would be looking for solid core plugs. I know that running resistor plugs with a magneto/coils is dicey at best. The resistors want to fry when not used with a more or less stable voltage range. You have to look a bit harder for solid core.
(Message edited by redmodelt on October 28, 2014)
Thanks everybody. If I can't get the NPK BP2ES I guess I'll be ordering up the adapters and experimenting with modern.
thanks to all. great info i will note.
what are the rajo folks running for plugs?
Clayton - On my RAJO model 30 (the earliest of the RAJO heads) I run Champion A25 plugs (also known currently as 525). I have them gapped at 0.040" and they run great. No fouling or misfires so far. FYI, I also run a Texas T distributor with points gapped at 0.018". Runs great.
thank you dave, i have a #31, it needs 18mm threads