Well, Challenge Bathurst time means it "fix the Datsun" time.
I missed last year's CB for family reasons (daughter's Year 12 formal and graduations were on the same weekend), this year is the grand "50th anniversary of the zed" celebrations so can't miss it.
1600 is still broken, for various reasons (holidays, home renovations, illness, got right into motorsport officialling - I'm now qualified as Bronze Event Command so can act as Clerk of Course at up to State level events - and not forgetting sheer laziness.....). Finally got around to doing something with it lately but its only going to be a refresh of the existing engine. So far, been concentrating on getting the head ready to be refurbished. It blew a head gasket, so will be off to the machine shop to check for hardness and straightness, get a few water galleries welded up (they're just a lilttle corroded but getting close-ish to the head gasket fire ring), new valve guides (I put new guides in last rebuild, its probably only done 1000k's or so and they're worn already ??), and I've treated it to a new set of valve springs plus going up a few sizes in cam from a 72 degree to a 76 degree (should work OK with the S15 closer ratio box).
I'm also tidying it up a little before dropping it off at the machine shop. Its always had the two end exhaust ports smaller than the centre ones, so going to even them up. Spent tonight working on the combustion chambers, just blending it all from the seat to the chamber itself - from the factory it has fairly large machining ridges so I've knocked them off with the dremel and will smooth and polish it all.
Then head to be checked / machined, and pull the bottom end out to be stripped down and check no busted rings, etc and just put it back together. If I can get a few more hp, and a few more revs out of it, and make it last for 2 hours around Mt Panorama, I'll be happy and will consider long term engine plans after that. Or I'll just keep driving it till it blows up again........
Outermost ridge to be blended into chamber :
Attachment:
File comment: Outermost ridge to be blended into chamber
IMG_0144.jpg [ 90.29 KiB | Viewed 4579 times ]
Preparing for some exploratory measurements:
Attachment:
File comment: Preparing for some exploratory measurements
IMG_0136.jpg [ 117.19 KiB | Viewed 4579 times ]
Takes the guesswork out of porting / working out where water passages are :
Attachment:
File comment: Takes the guesswork out of porting / working out where water passages are :
IMG_0138 (1).jpg [ 97.41 KiB | Viewed 4579 times ]