Now a bit more explaining.
There is a facebook group for L Series engine builders, all skill levels, The church of L series.
In that group I posted a pic of the camshaft with way more life and duration than it should have.
A nice back and forth with JeffP and he said I was doing it wrong, and that I needed to measure with the proper lash.
After a few trials and errors, I was able to get the lash dialed in correctly, and it showed that I have been measuring SOHC incorrectly. I did this one with a bit more lash, and it turned out to be a correct cam. Next time I will be measuring with the cam I plan on running with the proper lash, and adjusting it to see if I can get it closer to a 220/220 but this was a big help in problem solving
How to degree a camshaft.
No Idea, but I mostly do it in this video
I found a few things of interest while doing this, the main one was how close this and the Isky L-475 matched up mainly from what I was seeing and from this forum post. Because of that, I never felt out on a limb. I was worried with the initial viewing of the intake opening @.050 being 4* BTDC, but that post made me feel a good deal better about it.
I also did a @.025 measurement to compare it to how much was shaved off, there was .003 removed from it by the machine shop because of uneven wear on the lobes.
I am only right now, while typing this, realizing how useless that was, I do not have a pre-shave base to compare that to, so it really doesn't matter in the big picture.
I feel I should add that I do not think I did the absolute most accurate job with measuring the cam, but I did get it to within 2* overall.
I am currently having an internal debate to see if I want to advance the cam sprocket 4 degrees. A lot of that debate is coming from the summit racing calculator telling me that the camshaft is currently set to -4 advance.
Also notice how when I add 1 degree to the exhaust opening, everything smooths out.
So I will debate if I want to advance the camshaft, or drive it for 1000 miles with it in the stock 1 pin position.
The parts for this are:
Camshaft: Nissan Motorsport 99996-E1031 (Racer Brown 325-R-108)
I used two calculators just to verify my own results. After finishing the video, I also did the math. I used the formulas that are provided by Web Camshaft
Predictions: I should have a camshaft that has a decent power band that starts at around 2800RPM and keeps on till close to 6200RPM.
But there is not a way to be sure yet, I need to get the car on the dyno, so I might be over selling this camshaft.
And this post is going live a day or two before the youtube video.
Here is a quick video of my valve wipe pattern.
It was a simple setup, and this was for the camshaft that I plan on running, the
RacerBrown 325-R-108
It does look like it runs a bit off the backside, but it doesn't. Also this was done with zero lash, so when I set the lash to .005 and .007 it will not be as close to the end.
Also note, that the lash caps are being hit in the center, and that is pretty good because they are .175. It was recommended to go with .160 lash caps.
I will do one other camshaft, but I am not sure if I will include the wipe pattern with the next one in the video.
We have the head together, now lets bring it together with the block.
With this we had to put the head dowels in place, the machine shop did not put them in.
Overall the block is basic, not even a slight over bore.
The rods, pistons, and block are all within factory spec, the math will be shown later, and the rod bearings, main bearings, and rings are all ITM. They were all put together with the machine shop.
For the purpose of this first assembly we are reusing the stock head bolts, and they are not torqued to spec at this point. They are only run down to 10 ft. lbs. just to snug up the test head gasket. This is being done so that the camshaft can have the base degree checked and verify the valve events.
Once this is done it will be taken apart again to receive paint, oil pan, and a few other items.
Let's start this right, I am not an affiliate on any sites but the links below are the pages and parts that I have used for this head that is going into the 280zx.
We are working with a higher compression, and with that we need a cam shaft to move more air through this air pump. So what we have is a now built head.
The head had issues. When I bought the head off of CraigsList, it was at night, in a shed, in the farmland south of San Jose. I did not see the crack in the cam tower, or that the cam itself was broken, here is a pic.
I got lucky with finding a camshaft with towers on ebay, it can be found, but patients is needed.
The head eventually made its way to the machine shop in 2017. At the shop they did a pressure test, fixed the holes where there used to be exhaust studs, and it was decked. Surprisingly very little material was removed from the bottom of the head. It was "pretty straight" and did not need more than .001" removed to be completely straight.
There was no porting done on this head, but the exhaust valve guides were replaced and the cam towers were checked for straightness.
The head checked out fine, so they did the valve job, installed the valves, springs, keepers, retainers, and torqued the cam towers to spec. The cam was put in, along with the rocker arms, but a lash job was still needed.
The Cam Shaft
The camshaft was a complete luck find. It was a craigslist ad, about 90 miles away from home, and it was a Nissan MotorSports part 99996-E1031. I have the paperwork that the seller had. It was a decent camshaft. It looked to be in good shape, and the seller told me how the car would come alive at 3000RPM and just pull all the way up the RPM range after that.
The camshaft went to the machine shop with the head. During their checking of it, there was wear on a couple of lobes. They sent the cam out to be reground slightly, to be shaved so that all the lobes were the same. It was taken from .325 cam lift to .322 cam lift. This is not a huge change, it would take it from .475 valve lift to .470 valve lift. (.325 * 1.462 is as close as I want to get to the math)
The cam is now installed, and a lash job is completed, check the above video
Though all practical measures that were attempted show that the cam is only getting .450" of lift. My measurements may be completely off though.
The Assembly
The video above goes over the head assembly. I did not say it, but I show it. Use a good deal of assembly lube with the build. Check your measurements twice. Check your valve clearance. I will need to do this again, but I will need to do it on the lash not the cam next time. I will video that as well.
Check where your cam is hitting your rocker arms as well. You want the wear on them to be as close to center of the pad as possible.
This goes for the lash pads, verify that the rocker arm is striking those pads as close to center as it can. There have been people that mentioned that you can "move" the lash pad around, but I was not seeing a way to do that and keep the valve within lash spec.
Wrap Up
The head is together and sitting on the bench. Everything I have read, everything I have looked at, all the forum posts, the facebook posts, and the books show that everything should function fine.
The camshaft is not a large camshaft, it is barely over stock size. If I do not like its performance I can also swap it out with another cam. If it wears too quickly or eats rocker arms, again there are ways to replace those.
There are things in this build that people say you should never do. I have done them because I had to or was too naive to know better, I will let you choose which one.
I swapped the cam towers out, because they were broken. There have been that shouted from the tops of mountains that this should never be done. Time will tell if it works or not.
I replaced the rocker arms for a set found on ebay, I was also told that this should not be done at all, and either to get brand new, or maybe you can get away with your rocker arms being resurfaced. No mention of someone elses rocker arms though.
I have no history of this head before 2014. I bought this head as a replacement for the stock P79 head and to hopefully get 10:1 compression out of my engine. I got disheartened when the head fell apart on me and I tucked it under the bench for almost 3 years before I decided that there would be no harm in having it checked out, and it might save a few bucks over getting the P79 shaved.
I still might get my P79 shaved .080" down just so I can be like everyone else, but as for now, I am just gonna send it.
This car has had an interesting history, it was made in 1983 by Datsun, in the midst of the Nissan name change.
It was originally sold in Las Vegas, and the first owner had it for around 8 years. My step-father bought the car and became its second owner. He had it until around 2004 when he sold it to me. I ended up having the car for about a year, before i decided to move to Los Angeles, then I sold the car to my brother. My brother had the car for about a year, before he was moving and did not have the room for it, so he informed me, and I bought the car again. I had the car for about a year, and I found it a little too much to drive in in LA. I was not worried about the car breaking, but that it was an old car, it was a little too lively to drive in LA and I was working on other projects at the time.
My Friend had an accident in his car, in 2006 and I had just had my first kid. He needed a car, so I let him borrow it, and he enjoyed the car and made me an offer to buy it. I took the cash he offered and sold it him. He drove it daily for about six months, then he parked it with plans to start a restoration on it. The car wasn't in great shape at this time. It had 25 years of wear and tear, and more than a few miles on the clock. He had started looking into things, but oddly, he had to move soon and didn't have the room for it, so it went up for sale. He asked me, and within a few days, another friend had asked me about the Z, so I gave them each others number, and it was sold to another close friend. This friend was the 7th owner of the car, and for a 25 year old car, that had 250,000 miles on it, the car was running well, so well that he drove it from Los Angeles to Las Vegas without a problem. He was driving the car for about a year, and slowly putting things together, replacing broken parts, and then tragedy struck.
The thermostat housing cracked, while he was driving at about 75mph on the freeway.
It shot anti-freeze all over the place. The NACA vents allowed the steam to flow out the hot car quickly, and all but blinded his view.
The saving grace, he was in an area that did not have a lot of traffic and he was able to pull over safely, and let the car cool down to find out what happened.
He had patched it, and started working on getting the car back on the road, but life intervened again and again. He wasn't able to dedicate the time or resources for the car. It ended up sitting.
In 2013 he was moving to and I was looking for a project car at the time, he asked if I would be interested in buying the Z again.
This makes me the 3rd, 5th, and 8th owner of the same car.
I do not feel that this car is the end all be all for cars. I just know what I want.
What I want is a 200hp rear wheel drive car that is fun to drive and does not cost a lot to run or maintain. And I am making a car that had 145hp, and was at times scary to drive in LA, into a bit more of a hot rod.
This should be an exciting journey.
