Datsun Roadster Forum-311s.org

My plan was to make my car reliable for around town travel and enjoy it. That's what I've done and it's been a lot of fun to experience and drive the car(68 1600) as it is. It's needs paint, more power, a 5 speed, a working top and a bunch of other things but it's still so fun to get it out on the road. If the bottom end is good and you redo the head you could always just get it going and buy another R16 and take your time rebuilding and stroking that one. I had never driven a roadster prior to getting mine running so it was also good to see what it was like before I started planning what direction I wanted to go IF anything. I have to say I like it as it is for the most part. I just saw that you're in Lehi and work in Salt Lake so if you want to stop by West Jordan to see something for reference on my car you are welcome to.

Zion73 - I will shoot you a PM. I would love to check out your car! It's always great to get some inspiration and meet others working on these vehicles.

So at this point after doing some reflection and though I am swaying back to getting this car running and getting it out on a drive sooner than later. I like the point about just getting the car running with the current engine and then finding another block for a potential stroker. Heaven knows the SR20 bug may bite me before I get the stroker built. I guess we will see. If that does happen I may have a H20 stroker crank available.

So last night I tore into the engine to check the bottom end and see if it was fit to throw back together and run. In the process I found a couple of surprises (unfortunately).

First of all the crank journals look pretty good overall. There is a little bit of corrosion on journal #4 but the other three are clean and good to go. Overall though that wasn't the problem. As we were looking closer we noted some flaws on the cams. See the pictures below for some detail. It looks like I have issues on at least 4 of the lobes. The wear over it almost makes it look like there was porosity in the cam when it was ground bit that seems very strange to me. The wear makes it look like material is pushed over the areas in question. So it appears to me that this will require a new cam to prevent premature wear or damage to the lifters.

Speaking of the lifters I noted that one of them with a corresponding bad lobe feels scarred up like someone took a pick to it and scraped it up. See pics. New lifters required.

Everything else seems pretty good. Cylinder walls are clean mostly and minimal marks on the pistons from some dirty oil. Otherwise the engine is solid.

Then I decided to crack open the transmission. For a closer look and I found two teeth missing on the lower shaft. (The one that has (or appears to have) all of the gears machined into a single shaft). However all of the other gears are clean with no apparent damage. I am not sure if I can source a new one of those from any of the vendors.or am I going to be looking for another trans to piece together a working trans? It also seems like the front bearing on the input shaft is a little rough but it may just be dry.

As I mentioned before - I have a H20 I sourced and still need to get to my garage to tear down. In looking into things it appears I could also use the cam out of that as a replacement for my worn cam in my current R16. But if I am going to this pain at this point it seems like (assuming the crankshaft from the H20 is also good) it wouldn't be much more pain to just build this as a stroker.

Any thoughts on the cam damage, H20 cam swap, or the transmission repair options? Thanks everyone for your help!

Pics for my last post below.

The circled shaft would be the replacement I am after I believe.

You definitely don’t want to reuse that cam and I wouldn’t trust getting it repaired either. The cost of a regrind would be more than sourcing a good used cam. I don’t know for sure but I suspect that the H 20 cam would have a different profile than the R16, but you could compare part numbers.

Hey Mike - thanks for your response. My reasoning is based off of the Tech Wiki page for H20 interchange with the R16. See image below. I am not sure if this means the cam is the same grind or just fits. Hopefully someone can clarify here.

My cam had some similar damage although it was more a matter of more but smaller holes. The owner at the machine shop though that it was due to over revving so that the valves were floating and the lifters were coming off the surface of the cam and then the lobe would come around and hit the lifter.

Costine - that explanation makes sense given the shape of the marks. It also would explain why the material looks like it was mushed over after the fact - they kept driving after the incident and the lifter ran over the damage. Is valve float a common problem on these engines?

No answer but doing some seeaching and I have seen valve float at high rpm is mentioned as an issue. I have found one person that used the inner springs from a U20 head to stiffen things up a bit. I don't have those springs but I will be looking into it. Also the countershaft is toast so I am looking for a new transmission. If anyone has a known good 4 speed let me know. I am also going to put a post in the wanted section for now too.

I have come across at least one reference to over revving causing this same type of damage to heavy truck engines. It happens when a driver downshifts on a down hill in order to help control speed, but does it improperly so that the engine over revs when he lets the cutch out. I can't see it happening to our roadsters without some serious negligence. I have a spare transmission from a '68. I am not looking to ship it but I could do so if you can't get one nearer. I have shipped heavy thing before, and building a proper wooden box takes some work.

Shipping is not difficult. A large rubbermaid tub and some lumber scraps to secure the transmission inside the tub, then zip tie the top on. I have shipped two that way after Bob explained to me how he did it.

SPL310 - do you hav any pictures of how you packed it up?

This is a 5 speed I shipped to CA recently. Bubble wrap, cardboard, plastic strap to a small pallet and shrink wrap. Sent FedEx with no problem, weighed in at 80 pounds.

SPLutah wrote: Mon Apr 26, 2021 2:57 pm SPL310 - do you hav any pictures of how you packed it up?

Sorry, I don't.