CK5
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1970 Chevelle Malibu "400" Clone
- Thread starter 80' 427
- Start date
well I am an idiot and missed one rocker when swapping on the Harland sharps. Lifters quiet, exhaust leaks, not so much. This pair of headers is a pain in my butt. Why are all the header gaskets made for such a big port? These only have a 1.635x1.635 opening yet the gasket is 1.88x1.88 which is half way past the weld on the flange.
I think 241/245? I will find my card and post a new idling video after the city council meeting
The gaskets that come with headers are crap, I don't even bother with them.
If your headers have the protruding welded flange, I like the sandwiched aluminum header gaskets.
If they are ground flat on the flange and the flange is not real thick (only 1/4 or 5/16"), I like the percys carbon, or possibly embossed copper.
If you have flat flanges that are thick, 3/8" or thicker, the stainless gaskets can also work well.
All of them, have to fit of course, most gasket makers have several sizes and shapes for BBC and SBC.
Also, I always retorque them after it cools down for the first several heat cycles. Once they stop moving, could be 2 or 3 times, could be 6, then you should be good to go for a long time, over a decade if it's right.
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I am using a felpro gasket my machinist had and I can feel one leak and maybe hear a second.
I ordered some copper ones (the closest to the size of the port).
I usually just use rtv copper with no gasket and have minimal problems. I torqued them last night (as good as a could only being able to reach half the bolts with my wrench) I had to approximate with a double wrench the same length
I ordered some copper ones (the closest to the size of the port).
I usually just use rtv copper with no gasket and have minimal problems. I torqued them last night (as good as a could only being able to reach half the bolts with my wrench) I had to approximate with a double wrench the same length
Yeah, that's all it takes. When I say retorque header bolts I just mean by hand with a 1/4" ratchet or wrench. The headers vary so much and then you got cast manifolds I wouldn't trust a torque value. I go by feel, you can tell when it's tight enough and when you might warp something. You probably do the same thing.
These headers must be warped with all the problems I have had, so I just tightened them 30 ft/lbs. On every other sent of header I get it tight with a 7/16 wrench and check it 2 or 3 times and never have problems again.
Looks great!
it is a 20'er
Drove it to work yesterday and discovered: It had a oil leak after checking the rocker, valve cover gasket had slipped off the valve cover. It rattled when I rolled into it pretty hard in 3rd headed to the plant. I had previously bent the weights to limit total advance and it had the lights springs in it (all in by 2400-2500). Went to heavier springs that don't come in till 3200 and put on unbent weights. Now has 20 initial and 36 total. Still has a little run on so not sure if I need to get the initial down more. Should have about 23-24 deg of mechanical advance so my springs might be too light and advancing at the 900 rpm idle. Idles with 11in/hg. Need to hook up the vac advance to see if that helps the idle and add the PCV system. Had to slightly clearance the pan for the steering linkage and #3 header tube for the steering shaft clearance. It is on 6 month old gas so as soon as that gets empty I will get some fresh 91 for it.
I hope it does most of what I want.
Pics of it parked at the plant?
Martin
Martin
