When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I don't think the timing marks would be different from S4 to S5. I could be wrong, but TDC is in relation to the position of the engine when rotor one is at the top of it's compression stroke (stroke isn't the right word here, but it's close enough). The spark plug moving definitely affects the ignition timing but I don't think it would affect the static timing of the engine itself. So if the leading plug is firing at 5 degrees ATDC, and the plug moves from S4 to S5, it's still firing at the same "time" relative to the rotation of the engine. It's just that it's in a different spot, so that will have some effect as if ignition timing was advanced or retarded by that many degrees. The number in software and on the pulley doesn't change but in practice it would change the timing.
Or maybe I'm wrong. Between TDC, leading & trailing ignition, and primary and secondary injectors (both of which are full sequential from the factory), there is so much "timing" stuff going on in a 13B that it boggles my mind.
It's just a weird choice for the pulleys and hubs to be this way. Mazda put a lot of time and effort into everything else, but for some reason decided that pulleys and hubs could have like 5-10 degrees of variation and this wasn't an issue for anyone.
I was actually considering trying to make a post on this topic, but does anyone here know what the position of the keyway in the e-shaft is with relation to TDC? Because in theory this means one could use a degree-wheel and check against that to determine how accurate their hub is. It's a pain to disassemble the stack that far, but if you're in a position like Hot_Dog where the engine is already apart, it would be good to know.
Not much progress in the shop yesterday due to still awaiting parts deliveries. Other than more parts cleaning, I did start removing and replacing a few coolant hoses. I also replaced the oil filter pedestal o-rings. The coolant hose that goes from the heater to the engine is one that I am replacing. The connection on the engine side doesn't look to be in too good shape.
Probably is solid enough shape for me to reassemble the engine, but it will need to be replaced at some later date. Is this coolant connection replaceable? Does it have a Mazda p/n?
I replaced the oil filter pedestal o-rings. Been putting this off for a long time, but turned out to be much easier than I expected.
I was just wondering if I installed that bracket on the oil filter pedestal correctly? From some reason it doesn't look just right. Does it need to flipped over?
On an unrelated note, since I did have some downtime while waiting for my parts orders, I did replace the bushings in my anti-sway bar links. A number of years ago, I did the S5 to S4 control arm "upgrade" allowing me to replace my ball joints. So, I am using the S4 links. The original bushings in those links were badly dry rotted. I had bought Energy Suspension 9-8134G polyurethane bushings awhile back. I finally got around to installing them. I initially tried pushing the old bushings out with a vice and appropriately sized sockets, but that didn't work too well. So, I burned them out with a propane torch. The new bushings were tight, but I was able to press them in by hand or sometimes with the help of a vice. I also ordered from Energy Suspension the grease-able polyurethane mounts and brackets for my Eibach anti-sway bar.
For future reference, just wanted to add that there is no separate Mazda p/n for the FC coolant nipple (as shown in above photo) on the rear iron. However, there is a Mazda p/n number for the FD coolant nipple on the rear iron. Atkin's said that the FD nipple would probably work in the FC rear iron, although it's shape is slightly different. I bought an FD nipple and am posting a photo along with measurements that I took of the end that would press into the rear iron.
It is a good post, and the link in the post is good too. As RE has concluded, it's the hub. The only reason I think this was done is Mazda, at some time, decided to move the timing indicator. S4 to S5? I don't know, I only have S5 stuff.
I think Mazda decided it was more costly to change the stamping dies to make the pulleys than it was to just rotate the machined screw holes a little in the hub (probably CNC'd or fixture drilled).
Without multiple covers from all the different years, I won't be able find out, it may not be that visible just looking at them either.
06-18-23, 11:59 AM
