Spigot bushes are a small bushing which presses into the end of the crankshaft. The nose of the gearbox input shaft then runs inside this bush. You'll know when you need this bush due to a terrible racket it makes whenever the engine is spinning and the gearbox input shaft is not spinning or is spinning at a differnet speed. For this to happen the clutch must be depressed or slipping. I have found it can be made to playup abit when the engine is idling, the clutch is in and you start selecting gears at random. When its really bad, you won't be able to stop the noise with the clutch thrown out.

I buy mine for about $10 from Carters Clutch at East Maitland NSW. He usually has them in stock.

Getting the old bush out is tricky. Some people fill the crankshaft cavity with grease then get a snug fitting bolt in the bush (about 10mm diameter). Then they wack it with a hammer to create enormous hydraulic pressure which then pushes the spigot bush out. I've tried this and never been successful. We normally carefully cut a slot in the bush with a hacksaw blade then use a flat blade to remove the broken bush.

Good luck.

Rod length on A14's and A15s is 133mm centre to centre +/- 0.05mm.

Watch your compression on the smaller a12 chambers. You can actually go for quite a big cam with an a15 and still achieve 0.060" clearance between piston and valves.

I have a simulator which can give very accurate results with all this type of thing. Its very useful in designing engines. When you have a good idea of what you are planning to do, then I'm only too happy to run your specs through it.

Things I'll need to know are bore, piston brand and type, cam specs (or let me figure out the biggest), chamber volume and depth the valves sit above the head/gasket interface. If you give me head flow figures, inlet manifold dimenions, header dimensions as well then I can also give you a rough idea of flywheel HP.

Daniel

Yeah, I thought the secret weapon (CA16 powered) 1200 was going to be Chris' ride last weekend, but apparently its not finished. He's damn hard to catch now and he'll be even quicker with the new twin cam head plus god-knows what else. I've got a lot of respect for Chris both on and off the track.

I think they said it was an A15 and the carbies are off a Kawazaki of about 600cc capacity. 38mm throats if i remember correctly.

Its just like to say a big welcome to the two newest Datsun racers. Ben Haymen & Aiden Curlewis came along to the Oran Park supersprint yesterday in a smart looking 1200 sedan. Unfortunately a blown head gasket sent them home early after just one run each. Oh well, bad luck fellas - but thats motorsport. They still managed best laps of 1:35.14 & 1:39.43 on their first ever run there (3 laps total). Do you have any pics of the sedan to show here boys?!!

I know you'll do much better in the near future, especially under Chris Peterson's guidance and help. Chris set a new record for the NSW Cams supersprint series with a 1:23.94, 0.04 faster than his last previous record. I hope Benny and R-Fast get back real soon. the datsun clan will be bigger than ever before!!

...welcome to the dat side!!!

Hi. I'm planning to port my next head. Does anyone have any head flow figures ??? I've looked at Dattoman_1000's website. It has some figures but I'd like to get a better spread of results from different sized ports.

Neil, your image shows 'before' and 'after' figures. Was the 'before' figures for a standard port with standard valves ???

Can anyone recommend a place to have a head put on a flow bench??

I've often wondered how one could machine an E15 crank to fit into an A-Series block. I think the following is correct...

A Series have 50mm mains and 45mm big-ends.
E Series have 45mm mains and 40mm big ends.
All A series rods are forged. The only E series rods that are forged are the E15T motors.

Apparently, all A10's, A12's, A12a's, A13's and some A14's have forged cranks. Some A14's and all A15's have cast cranks. I'm puzzled at this myself because I have had an A15 crank, an A14 crank and two A12 cranks side by side, and apart from the stroke could see no visible difference. But I've also seen a photo of a different style of crank on this site. Its description said it was a forged A14, but I'm not completely sure which ones are which!! How can you tell ??

All E series cranks are cast, except the E15T's.

For low compression, you could use an A14 with A15 pistons with a low compression oval-port head. But I reckon if your coing to turbo, then E15T or CA conversion is the go.

PM sent. Re 13" rims, H165 and oil cooler.

Thanks for all the replies and links. They are greatly appreciated.