Recent content by Dale Davies

I the manifold is resting against the bolt when it is tightened, expansion and contraction of the cast manifold can cause the shear force. Another related to shear is the bending force as the bolt head sticks by friction and the clamp load. As the manifold expands and contracts, it slides...

Two qualities to discuss; tensile and shear. As the bolt grade increases the tensile strength increases through chemistry and heat treatment. This increased tensile strength provides higher clamping load, but at a cost, Shear strength. A gr 8 bolt will break in shear while a gr 5 or gr 2 bolt...

Yes, the washers are like ththick Belleville washers and appeared to me to be of a hardened construction. The Chev 'liners had similar washers. Everything engineered over the last 30 to 40 years has used metric measurements. Stepping up from the 5/16" or 8mm bolt or stud size to 9mm would be a...

Youse is overthinking da sityatun. Why do you introduce Gr 8 bolts? 9mm 8.8, 10mm 8.8 or 3/8 grade 5 bolts would be fine. IMHO the breakage is not from tension expansion of the manifold. Those bolts get plenty warm through heat convection from the bolt head in contact with the manifold. My...

Exactly so.

Back to the bean counters again. If they can save 1/10,000th of a cent per bolt times millions of exhaust manifold bolts per year, the bean counter justifies his/her position.

Like every proffesion, some are more competant than others, but are far from half wits. The problem these days is the bean counters are looking to keep every cent they can, so excellent designs get sent back to shave some happy cabbage off. I do not think the engineers are happy about it, but...

You have to be careful reducing bolt torque. Bolt torque is a method to determine and set bolt stretch in a blind hole. This stretch keeps the bolt from loosening and coming out. It works like lock washers do. You are correct 19DART66 in that there are 3 different expansion rates to consider...

Worked there for a bit and got along well with the parts people. That said, you may be correct. The service manager is a total dick, and I am not the only one to say that. I know Ram owners who drive an hour to get their trucks serviced or repaired, just to not deal with him. I went to a wrecker...

Yes Rusty, that is stupid. OEMs in their quest to save weight and money pretty much all went to 8mm exhaust manifold bolts. The General has a problem with the LS and 3.6 V6 breaking the exhaust manifold bolts. Drill and tap for 3/8" UNC or 10mm would likely cure the problem. Weight per vehicle...

Thread engagement for ferrous is 1.5 × bolt diameter. In Al, I would go 2 × to 2.5 ×.

Two thumbs up on that.

What is your intent and how much +camber do you have now? If you intend to slalom or track day with the car you probably want a heavy duty antiroll bar with about 3° negative camber and 5° caster. For a street driver your best bet is to follow factory specs. Seems to me this is a situation to...

4" bore and 4" stroke makes a good balance of torque and power. Mopar, Chev and Ford all have blocks to fit the bill.

I let the dog loose to chase the cats when I see them in my yard.