The bracket is a matter of maintenance more than anything else. I don't
consider it a design weakness.
The bottom ends are extremely stout. In fact, the crank and rods are beefier
than a SBC. Most of the engine is actually over-built.
The only weaknesses I have heard about only manifest themselves in full-race
motors. They are:
1. Less than optimal oil delivery to #2 and #4 main bearings. There is a
documented fix that involves drilling out the passages for better oil flow.
2. A shearing weakness in the nose of the jackshaft due to the double chain
arrangement, fixable by drilling back the bolt hole and installing a stud.
3. Extreme compression ratios (like greater than 13:1) can cause blown head
gaskets. They are hard to O-ring because of the notches at the top of the
bore for valve clearance. A perfectly round O-ring sits too far back from
the bore; one closer to the bore is no longer round because of the notches.
Gordon Glasgow
Renton, WA
www.gordon-glasgow.org
> -----Original Message-----
> From: owner-datsun-roadsters@autox.team.net
> [mailto:owner-datsun-roadsters@autox.team.net]On Behalf Of Ken Mack
> Sent: Tuesday, February 18, 2003 2:54 AM
> To: datsun-roadsters@autox.team.net
> Subject: Engine Questions
>
>
> To start a new question...
>
> How stout is the U20? I've read up on this death rattle, the bracket
> that goes around the cam gear that gets sheared off by the timing chain.
> Other than that possibility, has anyone experienced any other
> performance problems with it? Weak bottom end, lazy valve springs, poor
> ignition. I realize that the engine developed over 30 years ago, so
> yeah, it will have some limitations... but I want to hear about owners
> pumping some really good HPs out of it. I'd rather stay away from
> engine swapping if I can. I am coming to the conclusion that if I do
> not have a welding set... I am stuck with stock. Sorry, to all the
> purists, but I am a power hungry gear head.
>
> I think Tim Allen said it best... R R R R R R R R R R!
>
> Thanks for all you info and advise, thus far;
> Ken
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