[chuckies76ta]

I have a new set of Howard 98445. could test a few and let you know pressures. Might be to strong though for what your after. There a 399 lb/in spring.

[mgarblik]

I thought this was a rather strange find. While cleaning and preparing the FACTORY head bolts for re-installation, I found this! See the pic. The outer 3 bolts on each head, only the long ones are copper plated. So on each side there are 7 typical head bolts and 3 that are plated. This includes a couple stud bolts, one which has the negative battery cable attached to it. Has anyone ever seen this on any Pontiac engine? I have not that I recall. Is this an SD-455 thing? Kind of interesting at least. I am very confident these are the OE head bolts. All 20 have the same head markings. What do you think?

[johnta1]

Definitely for the SD 455. Not sure if the RA V's had them though.
The lengths are different than the standard heads.

[PAUL K]

All round port engine used the copper colored head bolts. They are belong in the exhaust port bolt holes. I'm thinking the copper color was to alert a person they need to go in a specific place. Sadly it's not uncommon to find round port blocks with heli-,coils in holes where those bolts belong. You will pull the threads out if you use the shorter standard bolts. The copper bolts are 4". One studded bolt goes on the LH front for the battery ground. The other one goes in the RH center for the A/C support bracket.

Not sure what the factory recommended for the RA V engines but the the 4" long copper colored bolts will work.

[mgarblik]

Originally Posted by PAUL K

All round port engine used the copper colored head bolts. They are belong in the exhaust port bolt holes. I'm thinking the copper color was to alert a person they need to go in a specific place. Sadly it's not uncommon to find round port blocks with heli-,coils in holes where those bolts belong. You will pull the threads out if you use the shorter standard bolts. The copper bolts are 4". One studded bolt goes on the LH front for the battery ground. The other one goes in the RH center for the A/C support bracket.

Not sure what the factory recommended for the RA V engines but the the 4" long copper colored bolts will work.

Once again, learned something new today. First SD-455 engine for me. I have had a couple 455 HO engines apart and just do not remember seeing the copper bolts. So the copper color is just for ID of the extra long bolts? Interesting. Makes sense.

[Shiny]

Very interesting to see!

I'm skeptical they'd pay to plate and hydrogen-relieve just for ID. The bolts are longer, not easy to confuse.... ???

Any chance the copper is to reduce galling? Like anti-seize?

Do these bolts have higher risk than others by being close to exhaust?

[johnta1]

I thought it was mainly for the heat. Also possibly to keep the 'rust' from getting bad on them.

[PAUL K]

Originally Posted by Shiny

Very interesting to see!

I'm skeptical they'd pay to plate and hydrogen-relieve just for ID. The bolts are longer, not easy to confuse.... ???

Any chance the copper is to reduce galling? Like anti-seize?

Do these bolts have higher risk than others by being close to exhaust?

Originally Posted by johnta1

I thought it was mainly for the heat. Also possibly to keep the 'rust' from getting bad on them.

That's a good point. Maybe, they do go through the through the exhaust ports (but not exposed to exhaust). The factory didn't miss much. But it would make sense to have them color coded for "hand assembled" engines. It would be a disaster it the shorter bolts were used and stripped the threads on a new engine. I'd think the factory would consider it scrap and the parts manager would have a happy day.

[sdbob]

I have nos bolts. Yes they are copper colored. The other bolts of mine have greenish color.

[mgarblik]

Thanks for verifying. Heads to be installed tomorrow.

[steve25]

If that’s a flash copper plating I can’t think of any reason for them to only be used in 3 out of the 6 bolt holes that pass near exh ports.

Now the studded one can be seen to be used possibly for producing a better ground connection on the studded end and then also by the threads in the block.

Conversely the copper if originally was on all the bolts might have been used in place of any lube .

At this point in time we may never know the true intentions for this interesting detail.

[mgarblik]

If Herb Adams comes to Dayton again for the TA Nationals, I will try to remember to ask him. I just bet he knows exactly what the intention was and why they are in there. Can't think of anyone else off hand. Although I like the idea of the copper plating improving the ground location for the negative battery cable. What about the 700,000 other Pontiac V-8's that didn't get that stud bolt that year? They still needed a good ground. Just another interesting little Pontiac tidbit.

[Big Bear]

When I dug out my bolts there were a couple of washers still on them. Measured .060 thick. Dont know why they used them but was talked about on this site some time ago. There was GM part number for them. Sourced .100 thick hardened washers and used them on the reassembly.

[mgarblik]

Originally Posted by Big Bear

When I dug out my bolts there were a couple of washers still on them. Measured .060 thick. Dont know why they used them but was talked about on this site some time ago. There was GM part number for them. Sourced .100 thick hardened washers and used them on the reassembly.

Those washers were under the heads of all 20 bolts on my engine. I had no idea they were factory installed. But since found out they were supplied on early SD engines for some reason not clear to me. The washers were not hardened or parallel ground. They were also deeply embedded by the bolt heads. IMO, a bad idea to use them as they would certainly would lose clamp load as they relax from being embedded. I replaced them with hardened washers, .120" thick. They are parallel ground and the little extra thickness makes up for square decking the block and making the heads flat again. The OE washers were also a poor fit on the OD and the ID. The ID was too large and let the washers move around over 1/8'. The OD was so large it overlapped the poor factory spot facing on the top of the bolt holes, bending the edges of some washers. Overall, not one of Pontiac's best designs. I thought someone just threw some hardware store washers under the bolts until I learned they were factory installed.

[steve25]

If the concern at factory was that the bolts would first bottom out in the holes before reaching the needed torque spec, then with the added costs of the SD motor you would think that parallel ground washers of the right ID would have been used.