Rocker gear doesn't have to come all the way off - just loosen the bolts enough to pull the push rods out. Watch the coil bracket too.

Thanks guys. Yeh i have made the decision to pull it of, i suppose knowing it was like that it would always be in the back of my mind. I currently have the rocker cover of, brake booster removed because it sits close to rocker cover, no point putting it all back on and then having to take it of again.

My guess is when i got the motor rebuilt they may have re-used the same head bolts? Im uncertain of this as the one that snapped did look pretty good (besides it breaking), but i know 50 year old bolts are probably stretched or weak. Im trying to work out things to buy. In Australia we have a few different suppliers of Valiant parts and im trying to work out best head gasket to use, as some you can get are cork, fel pro, metal ect. Also i know i can source Arp stud bolts, but i want to ring a few places and see if i can get Arp Bolts to replace all the head bolts.

Its not a all out high performance motor but it does go a lot better then standard as i have fitted electronic distributor, extractors and sports exhaust, 2 barrel manifold and 350 holley, the motor was rebuilt to suit unleaded petrol and lpg as the car runs on dual fuel, both unleaded and lpg. Recently i just converted it from 3 speed manual column shift to automatic with a torqueflite 904 also column shift, it has a standard dominator brand stall converter, shift kit and thats about it.

So while i have the head of im pretty sure all the valves, stem seals ect are all still good, but should i look into maybe porting / shaving the head to gain more power? As far as i know the cam is still a standard grind. Any advice on what i could do to gain more hp? Thats the way im heading towards, or i will simply pull the head, get the broken bolt out, replace gasket and drop it all back on and replace all head bolts at the very least. I have to ring a few places and see what it will cost to do some modifications to head, that might make me decide either way.

Cheers

For that bolt to break it had to already be severely compromised. It wouldn't have been carrying its full load of clamping force.
Probably, at some point the head gasket would have started losing its seal.

By replacing it now (and all the rest of 'em) you are heading off what would have been a worse situation.

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https://www.amazon.com/Pioneer-Automoti ... B0049JKPN0

Is what I come up with for the part number for head bolts. I assume that is a set but not 100%.

Edit: Oops, just noticed you are in Australia....don't know if the link will help or not.

sb

Just thought of this.

Try one of those handheld impact (hammer) screwdrivers without taking of the head first........

Maybe you'll get lucky.

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Ed
64 Valiant 225 / 904 / 42:1 manual steering / 9" drum brakes

Thanks for that mate. Says they wont post to Australia. I think that would be for the set as $34 each is expensive, but $34 for the set is very cheap. Arp studs range from $10 - $14 each and when you have 14 to buy that can be pretty expensive. Everyone i talk to about it say Arp studs is over kill and only need to use them on a hot worked up motor. On Monday i will take in a good bolt and see if they can match it up with anything, i will either just replace that or change the lot and buy all new bolts, it will be cheaper then buying the arp studs. Vpw who deal with this sort of stuff said there is only a listing for studs to suit the slant motor and don`t sell bolts to suit, but im sure they will be able to match it up with something else. They sell the set of studs for $154

Probably already have head off! Some good advice that I think you overlooked!
The remains of the bolt should have been easy to have retrieved....if you have not got the head off yet, give it a go. it should unscrew with your fingers, not sure why you are talking about vice grips and welding nuts on.

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1967 VC Valiant

You should be able to easily locate a head bolt. Any engine shop would have a collection of head bolts that may well suit...or deal with Hemi performance or as much as I hate to say it pentastar part$$.. they aren’t cheap but for a single bolts it’s worth it. You don’t need to buy ARP or import for a simple part.

No i have not taken the head of yet, it was way too hot to be working in my garage. I haven`t brought new bolts either just yet. I will see how i go and maybe try to retrieve the bolt first, i doubt it will come out easy thats why i think the head has to come of, but i suppose i can try my luck first. If i get away with getting the remains of the bolt out, then i will just source a 2nd hand bolt. Thanks for the advice guys.

Well good news everyone!

I gave it another go before, i got a screw driver and pushed down hard onto it turning it to unwind the bolt, i did this a fair bit not knowing if was actually working, then blew compressed air into the bolt hole and the broken bolt came straight to the top for me to grab out. I am so happy now that i don`t have to remove the head, i really did not think it would come out. Thanks to you guys and nzpete i thought i`d give it another go and yep it came out pretty easily. I initially thought the bolt was too low and had too much force when done up that it wouldn`t come out easily. But the gods were on my side today and i am so glad. Now just need to source another bolt, i will replace it with a 2nd hand bolt. What the best way to do this now? Should i undo all the head bolts and re-torque again in the correct sequence? Im just so worried and don`t want another to break on me. I might even try a different torque wrench this time.

I'd just install the one bolt and leave the others torqued.


I'd also run the bolt down without the washer so you can see that it won't bottom out.

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Ed
64 Valiant 225 / 904 / 42:1 manual steering / 9" drum brakes

My head bolts don`t have any washers on them, im pretty sure thats how they are meant to be. I am going to put something down and measure it to check for bottoming out.

Slant six's don't have head bolt washers from the factory. Usually used on a high performance build. They will allow a greater clamping force, with the same torque reading as compared to no washers. Also keep the bolt from going too deep in the hole if the head/deck has had heavy milling.

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Charrlie_S
65 Valiant 100 2dr post 170 turbo
66 Valiant Signet 170 nitrous
64 Valiant Signet
64 Valiant 4dr 170
64 Valiant 4dr 225

Does not sound there is a down side to using a washer. Maybe just a 7/16" Grade 8 washer for wogboy?

sb

I checked for bottoming out, and there is still another half an inch longer then what the bolt is, so that wasn`t the reason for it breaking. Anyway i got some replacement bolts, replaced the broken one, i didn`t torque it right up because im a bit cautious now when using 2nd hand bolts and the head gasket has not been replaced so its already formed to shape. So i just nipped the bolt up to what i thought was firm, i ran the motor until it got to normal operating temp and with out the rocker cover on and made sure no coolant escaped through the bolts. Now have let it cool over night and im going to just turn the bolt a little more and that will do, don`t want to force it to 65 ftlb like the book says. I also went out and brought a new torque wrench to use.

Also i don`t want to use washers if the motor didn`t originally have them, besides that i would have to undo all the bolts then to fit washers to all bolts so they are all the same, and i don`t want to mess with the clamping force it already has on the head gasket, also bolts can break even when undoing them, so like the old saying goes "don`t fix what isn`t broken" im just gonna leave it alone haha.