Restoring Rusty

[Gregski]

best thing about 70s SMOG exhaust manifolds is that they make terrific hold it downs for when you need a third hand like when you is a welding

[Gregski]

and the driver side noodle ready to go back on absent the resonator

[Gregski]

brand new set of AC Delco R44LTS spark plugs rode shot gun home with me, then we gapped them to .050" to make the H.E.I. distributor happy

made in Mexico so they gotta be good

maybe I already ranted about this maybe not, but GM recommends R43LTS in one 350 HO engine spec part number 19210007 and R44LTS in another part number 1921008 for the 350 HO Deluxe engine

[Gregski]

tested the #5 plug wire with one of these Hazard Freight flicker jobbies, hey its from Harbor Freight so it's gotta be good

[Gregski]

Originally Posted by rich weyand

Also, after a dozen or so temperature cycles, torque them again.

Once they're tight, they'll stay that way, but to get them there, you have to get them to conform to the heads.

Rich I literally went dumpster diving for the REMFLEX instructions since I recalled seeing something in there about "they don't require re-tightening!" something to do with their rebound properties

please see below

[SkinnyG]

I've been very impressed with Remflex header gaskets. I use them on everything now.

I have been most unimpressed with Mr. Gasket anything.

[hatzie]

I've always had to re-torque headers because the bolts loosen up from thermal cycling. The gaskets are almost secondary.

[hatzie]

I've always had to re-torque headers because the bolts loosen up from thermal cycling. The gaskets were almost secondary.

Those gaskets might be worth a second look.

[68Timber]

It looks like the flange is the problem, not the gaskets. The round flange with square gasket ports isn't giving much of seal in the corners. If you built up the corners with your welder and smoothed them with a flap disc you'd have more surface area on the gaskets all the way around.

[68Timber]

Originally Posted by 68Timber

It looks like the flange is the problem, not the gaskets. The round flange with square gasket ports isn't giving much of seal in the corners. If you built up the corners with your welder and smoothed them with a flap disc you'd have more surface area on the gaskets all the way around.

Based on soot patterns on the flange in post 4654.

[Gregski]

Originally Posted by 68Timber

It looks like the flange is the problem, not the gaskets. The round flange with square gasket ports isn't giving much of seal in the corners. If you built up the corners with your welder and smoothed them with a flap disc you'd have more surface area on the gaskets all the way around.

Bro I had the exact same thought, I may just have to do that

[rich weyand]

They brag about not having to re-tighten the header bolts because everybody and his brother-in-law knows that 1) you have to re-tighten header bolts, and 2) it's a PITA.

The temperature cycling loosens the bolts. Let's put it this way. If temperature cycling causes the bolts to squirm, they aren't going to make themselves tighter.

The other issue is that the headers, once they have been heat cycled, move about a bit as well. Sort of like the metal pops you can hear from the ductwork in the house when you run the heat for the first time in the fall. The expansion causes the metal to squirm about a bit, to find itself.

Similarly, once a set of headers has been heat cycled a few times, when you take them off you find that the bolt holes aren't all quite in a line any more, and the head flanges aren't all quite in the same plane anymore. The header tubes are different lengths, with different bends, so they react differently to the heat.

The heat-cycle-then-retighten is to keep working the bolts until you get them to a place where they are happy and stop squirming about. I have the garage check torque on mine with every oil change. Once in a while they find one a bit loose. Usually not any more, but for the first couple of times after the new engine went in, there were multiple loose ones.

The tighten-while-warm is to get the head flanges all agreeing again on being in the same plane and the holes all in the same line while the header pipes are a little flexible, so you can get a pretty uniform crush on the head gasket, rather than have it tight on one side of the flange and not on the other.

All that being said, as you said above, headers are more prone to leak. That's why the factory doesn't use them. If they didn't leak, given that they provide benefits of power and efficiency compared to cast manifolds, cars would have them stock from the factory.

[harley87ta]

From your pics looks like the new gaskets cover your header ports pretty good

[Jake Wade]

Felpro 1444 header gaskets have never failed me for an application like yours.

[Gregski]

Originally Posted by Jake Wade

Felpro 1444 header gaskets have never failed me for an application like yours.

Thanks for the part number. have you used them on the L31 Vortec heads specifically, I believe they are a different animal, and maybe more important have you used them with the Hooker Comp headers, I think the headers are the issue here

[Gregski]

So what is The Greg up to when he's not chasing exhaust leaks?

Well I've been tuning the carburetor in preparation for maybe one more dyno pull before this year is over, I am really hoping for 300 horse at the rear wheels.

I get really Geeky with it in my sister thread INNOVATE DLG1 Wideband O2 Oxygen Sensor Tuning Diagnostics Logging Air Fuel Ratio etc if you aint seen it yet.

This means converting my 4160 Holley carb into a 4150.

Here are the pics of the 4160 model with a thick metering block in the front and only a thin metering plate in the rear

[Gregski]

and here it is all "converted" to a 4150 using the Holley Kit Part Number 34-6SA

if there is one thing I love about Holley is their very super simple part numbers

the kit just comes with a secondary metering block and a longer straw aka transfer tube and some hardware ok and new gaskets

the metering block is super lame, the idle mixture holes are there but are not threaded nor drilled all the way through, so you do not end up with what they call a 4 corner idle

the block also does not have an opening for a power valve nor pre drilled holes for a secondary accelerator pump, but that's ok, this is not a double pumper

[Gregski]

so since you didn't ask I'll share anyways

a plate is like saying something is hard coded, ie it is not adjustable, you want to change the way the secondary circuit flows you gotta buy a whole new plate with different termite tunnels in it

a block on the other hand is adjustable though not all blocks are created equal, in this one for example the only thing I can adjust or replace are the jets, but hey that's better than nothing

A company called Quick Fuel Technologies does it right they make Holley like carbs with metering blocks that you can adjust everything on, emulsion tubes, idle jets, power valve restriction channels, say what? yeah you heard me

here we stare and compare a secondary metering plate to a secondary metering block

[Gregski]

alright so now we are cooking with Propane! ha ha

but we want more...

we want new center hung float bowls with sight glasses for adjusting float levels cause that remove a side bolt and watch fuel poor out on to the hot engine block aint no fun

[Gregski]

but of course the new float bowls come plane Jane naket so now we need to source new center hung floats and their hanger hardware and we also need new DUAL inlet hard fuel line to replace that pesky transfer tube

[Gregski]

so nothing to it but to do it

so yeah the old 4160 came with side hung floats (who knew there was different kind am I right fellers?) now not all 4160 carbs come with side hung floats, some do come with center hung, all that 4160 means is one block and one plate but we already pounded that horse to death

so yeah the floats aint transferable (kinda like my junior college recreation and leisure class, ha ha - I'm looking at you American River College)

[Gregski]

and yeah the 200 lbs Gorilla did break the Accelerator Pump Umbrella Check Valve whilst trying to transfer the Accelerator Pump from the old float bowl to the new one - I mean sometimes I don't know my own strength

(yes I did just use the word "whilst" it's a lost art I tell yeah)

[Gregski]

so went to the local Hot Rod Shop to pick up one $10 dollar replacement part and came home with this

this ever happen to you fellers?

[Gregski]

alright got the new Umbrella Check Valve installed and got the Accelerator Pump transferred

[Gregski]

and got my new 4150 carb all buttoned up, looks more and more like the real deal now don't it?

nothing against Edelbrock but Holley is just a sexier carb in my opinion