This marks yesterday's and today's progress.
I pulled out my diffusers and realized "Oh, these went through the chemical bath when I had Arnold Motor Supply clean them". The o-rings feel like they would break easily (they are hard, probably brittle), but the diffusers seem ok. Anyone know of suitable replacement o-rings I could pick up at a hardware or parts store? They need to withstand fuel, of course.
Here we have my two practice irons (I really wish I had a center iron to practice on, I'll have to do it another time). I basically followed the Mazdatrix porting video as well as I could, but I don't have quite all the rotary bits needed to do everything they instruct. I think I got pretty freakin' close for what I had. After I was done porting I dug deep to get an idea of where the water jacket is. Apparently a lot of people have tried to cut STRAIGHT DOWN from their port opening and end up with a useless iron. If you ever want to port your 13B, bear in mind that it is NOT beneficial to airflow to cut far straight down anyway. I did not cut straight down at all, and from what I've seen reputable builders also do not cut straight down (I
am only talking about the closing edge).
Before I started porting I took at least two hours tapping these two threads... It was annoying, but these brass fittings should last a long time and more importantly, they will be EASY to replace if I ever need to do so. I removed the old nipples because they had some rust and I've had these types of nipples break on me before. It's a huge PITA to fix while the motor is in the car (not to mention hazardous and troublesome to say the least if it happens while driving). I didn't have a drill bit big enough for the big hole, so a lot of time was used cutting it out with the die grinder. I had to do the same for the small hole because my drill chuck isn't big enough for the right sized drill bit. Yippee. At least I got the little one out without cutting the nipple up like I had to with the other one
Before I did this I was warned to be careful not to crack the iron around the thread. I
was careful and that was another reason it took so long. I'd much rather back it out many times and cut more out periodically than do it fast and have to search for, buy, and then wait for another iron.
I ported the secondaries first, as that was what I practiced on, and they went smoothly. Please note, I did not take pictures of EVERYTHING, as it isn't really necessary and it is time consuming trying to photographically document absolutely everything. The runners were pretty easy, just use your head. They go quickly, too, which was nice.
While I was told that I could use my Racing Beat street port template as-is for all four ports, I decided to shrink it for the primaries.
A) I can't afford (time nor money) to mess them up trying to open them wide up to anything like the secondaries.
B) This does need to be streetable and I like keeping a low profile when it suits me, I suspect I would have to set the idle a bit higher if I made the ports very large.
To accomplish this I simply drew reference marks on the template to show me where the new lines would intersect, marked the intersections on the plate, and scribed the official line by hand.
Since my split mandrel and sandpaper strips won't arrive for about a week I decided to make my own. I would have preferred to shave and cut a bolt for a mandrel, but that would have taken precious time. Also, the best sandpaper I have for the job was 320 grit. 220 is the finest recommended by Mazdatrix, so I went light on its use. The main purpose was to ever so slightly smooth the sharp corners of the inner port openings, I think it did the trick. Good old fashioned ingenuity.
I'm proud of these babies, I think my first primary ports came out well (again though, I don't have all the proper bits so they aren't quite as smooth as would be preferred, but I think I will still receive most of the benefits of this type of port job.
FINALLY, some clear pictures. I think some of the fuzzy pictures are because I was too close and others because I don't have terribly steady hands with something as light as a camera after hours and hours of porting. These are as done as I'm going to be able to get them. I would like some opinions on whether or not these will be safe and reliable for extended use, mainly because I'm nervous about my first build. I was very careful not to nick the faces and not to go past my lines except to very gently blend the sharp points where the template and stock ports didn't meet smoothly. There were one or two very, very minor spots where I went over a line. I remember once was probably .5mm past the outer opening edge line and once was about the same past the closing edge. Should that be ok?
