6 Months Later...Update On My '67 Datsun Roadster Many Pics!

[MAG58]

Revo's are the next most popular thing to Minilites in the Mini community. I got a set (of both) at a mini swap meet. Since they're so plentiful, a good set, even a good knockoff set from england aren't that pricey.

[junglist]

Looks incredible. Way better than my hulk of a '66 1600. Mine does have a U20 Motor with Mikuni's and a 5 speed in it though its not currently running.

[slownrusty]

Thanks guys!! I appreciate the comments and kudos!

 

Yasin

[josh817]

Now is that a 2000 or what? I'm doing a motor for a dude and parts are horribly expensive, I feel bad for the dude. Since we gave him a set price instead of hourly labor, I thought I might as well do the most I can while we wait for parts to come in.

 

 

 

Don't rev the poor thing up too high. I was informed that like 6000-6500RPM is the highest you should go before your bearings decide to take a dump. Everything on the bottom end is hideously heavy. Untouched rods were 912 grams. I finagled them down to 840g and I bet I could have gotten more if I touched the bottom of the big end however this motor is warrantied so I don't want to get too crazy... I did take off lots of material around where the bolt goes through the rod, as you can see. Comparison would be like... our stock 240 rods were 700 grams I think. I can't remember what I had mine to but those weren't really lightened.

 

Bearing that took a ****:

 

 

 

So, nice car! Baby it. You don't want to rebuild a U20. The pushrod 1600 was cheaper last time I checked.

 

EDIT: Not all the pictures loaded the first time. D: I love the wheels and I see its a 1600! Valve cover is different too.

[junglist]

Don't rev the poor thing up too high. I was informed that like 6000-6500RPM is the highest you should go before your bearings decide to take a dump. Everything on the bottom end is hideously heavy. Untouched rods were 912 grams. I finagled them down to 840g and I bet I could have gotten more if I touched the bottom of the big end however this motor is warrantied so I don't want to get too crazy... I did take off lots of material around where the bolt goes through the rod, as you can see. Comparison would be like... our stock 240 rods were 700 grams I think. I can't remember what I had mine to but those weren't really lightened.

 

 

Thats not what Bob Sharp says in his Datsun Competition Preparation Manual that was published in the 1960's. He says in section 4-14 in regards to the Camshaft:

 

"Although the stock Solex camshaft has proven to be quite efficient at 6800RPM, more horsepower and higher revs can be realized from a re-ground unit. The Solex cam has enough material to grind almost any profile that will give horsepower readings of 185 at 7200 RPM's."

 

and in section 4-16 in regards to the Valve Springs:

 

"The stock valve springs are totally adequate for use with the Solex camshaft if the revs are held to 7000 RPM's. If a racing cam is used and the revs will be exceeding 7000 RPM, it will be necessary to install a spring strong enough to accelerate the mass of the valve train at such a rate that the rocker arm will stay on the camlobe at least 500RPM above the desired red line."

 

I'm not saying that manual is gospel, but Bob Sharp was pretty successful and if that manual was written in the 60's and he was running it at high RPM's back then. Well, we must have better components & bearings nowadays that would allow you to run at least at the same higher RPM's.

 

If you don't have a copy of that manual or haven't read it, you can download it for free at www.Datsun.org

[josh817]

Thats not what Bob Sharp says in his Datsun Competition Preparation Manual that was published in the 1960's. He says in section 4-14 in regards to the Camshaft:

 

"Although the stock Solex camshaft has proven to be quite efficient at 6800RPM, more horsepower and higher revs can be realized from a re-ground unit. The Solex cam has enough material to grind almost any profile that will give horsepower readings of 185 at 7200 RPM's."

 

and in section 4-16 in regards to the Valve Springs:

 

"The stock valve springs are totally adequate for use with the Solex camshaft if the revs are held to 7000 RPM's. If a racing cam is used and the revs will be exceeding 7000 RPM, it will be necessary to install a spring strong enough to accelerate the mass of the valve train at such a rate that the rocker arm will stay on the camlobe at least 500RPM above the desired red line."

 

 

I'm not saying that manual is gospel, but Bob Sharp was pretty successful and if that manual was written in the 60's and he was running it at high RPM's back then. Well, we must have better components & bearings nowadays that would allow you to run at least at the same higher RPM's.

 

If you don't have a copy of that manual or haven't read it, you can download it for free at www.Datsun.org

Please note that the first quote is referring to a camshaft regrind and the second one is referring to valve springs, neither are referring to the bottom end capabilities, and both quotes are referring to a competition preparation manual where its probably assumed that there are other things needed to be done in order to achieve a more reliable high RPM. He also says things like using a "special Vandervell bearing" which has "special oil grooves" and a "thicker shell" for racing purposes, those purposes being higher RPM's and the necessary lubrication so you can finish the race.

 

Greg Ira's shift point is 8500 RPM for his race motor. Does this mean I can take my street motor and shift at 8500 RPM too for 100,000 miles or do I want to rebuild a motor/change bearings after 50 hours of use? We have to remember my usage of the word reliable varies on from track to street. Track reliable is finishing the race(s), measured in hours. Street reliable is, for a Datsun, more than 150,000 miles. We all know our toys don't break in until 75,000 miles!