How do you modify the dizzy to clear ARP head bolts:4AGZE?

[benjamin]

Well I seem to have found a problem with the length of the CAS. The gear on the shaft seems to be further down the shaft than it should. I put it back in the old smallport head with this camshaft and another one and it was still fucking around (I mean meshing with the gear on the camshaft) but when I pull the CAS a little bit out of the dizzy tunnel it gets much better so I need to get myself another CAS assembly and see what the hell is going on...

[takai]

The drive gear is pressed onto the shaft afaik, it may have come loose, or the bearing in the body of the CAS may have collapsed.

[Ben Wilson]

The gear is held onto the shaft by a pin, there is no way it's going to slip.

[takai]

One of my smallport dizzys didnt have a pin in it when i got it with the spare engine.

[Adsport]

hi mate, ive had this exact problem in an AE86 with bigport 4age+T, we didnt realise at first and it actually bend the dissy shaft. ended up just lopping the last bit of the shaft off (well i took off as much as i could) and havent had a problem since. you could always shorten the bottm of the stud as Kingmick said.

[legend]

i have got this problem to i chased the threads 4 times in the gze block and the cas shaft hits the nut on the ARP stud
could i machine 4mm of the dizzy shaft or would it cause a problem

[Grega]

yes..........take a bit off the end of the dizzy shaft.......CAREFULLY. i have this EXACT problem in my combo - 4age 7 rib bottom end, bigport head with ae86 dizzy.
i'll take some pics when i think of it and show you. my dizzy sits in place just fine, but, i reckon theres 1mm in it which might foul when things warm up.

[damo101]

i had this problem aswell..i just ground the end of the shaft on the bench grinder..hardened steel my ass!!

[Grega]

yup
heres the problem

its pretty tight innit?

[benjamin]

Hey thanks for all the help guys. I only just realised this thread was still going. I got another CAS and found that the gear on my old one had slipped down the shaft. When I had first installed the CAS, the shaft was rubbing against the Head stud. When the engine was turned over obviously the camshaft was still turning and trying to turn the CAS aswell. Because it was jammed so tight against the head the shaft wouldn't spin with the gear so it was forced by the camshaft gear down the shaft (mine was only pressed on and not secured with a pin, it's still tight enough as there normally isn't much resistance in the CAS) and this also completely threw out the timing!

When I got a new CAS I took out the head stud and shortened it down so that it just protrudes above the nut. And now I have perfect clearance between the CAS shaft and top of the stud. Expensive way to find out a pretty simple solution...

[legend]

i went for the dizzy mod work's a treat
thanks

[DeftAnesthetik]

On my 4ag, it was built with arp fasteners with the exception of the one right under the dizzy which uses a standard head bolt. arguably this could be problematic. but by far the best solution out there. i dont like the idea of grinding what should not need grinding or modification, especially something as important as a dizzy.

[Adsport]

its not like you are altering the way it works, your just machining off unused material...... i think what youve done is the easiest and slackest solution out there ! certainly not the proper way thats for sure

[DeftAnesthetik]

its not like you are altering the way it works, your just machining off unused material...... i think what youve done is the easiest and slackest solution out there ! certainly not the proper way thats for sure

definately the slackest way of getting it done, but was not done by me. My final engine assembly was done by a Toyota master level mechanic. I trust his judgement. ~20,000km on rebuild and still taking a flogging.