Inside the 200 head ?'s

[LameHoof65]

Didn't really know exactly where to post this, so if there is a better place just send it and I'll pick it up if anyone has a response. I know this ? has been asked---but has anyone found a detailed blueprint '3D like. Or has anyone disected or cut up an old head. You know, I think I need that before I try to start drilling for studs where the old intake and exhaust were? I was thinking probably anywhere between the cylinder walls would be okay on the base, but what about up closer to the intake?? Also, I was thinking that if I decide to do the stud type mounting what size studs would be the minimal size, grade I should shoot for---and what about depth for holding? about 1/2" in 8 to 10 threads--with loctite??? If anyone has any answers to this or can lead me somewhere to get them I would appreciate all you have to offer.

 

[Anonymous]

For fasteners- the general rule of thumb is that you get full strength from the joint at 1.5 diameters of thread engagement. For example: A 1/2" diameter bolt will have full joint strength when screwed in 3/4". Any more than 2 diameters is overkill, and increases the risk of tap breakage.

For a lightweight intake manifold, a gang of 5/16-18's or 1/4-20's should suffice. You don't have to drill too deep (if you use a good bottoming tap). Shallow drilling is a good idea here, since you're not sure where the water jacket is.

Af far as fastener grade, I'd say Grade 5 for the intake. If you torque a fastener properly you shouldn't need loctite. But in a heat-cycled area like this, it's not a bad idea to loctite the studs in. Or you can use bolts with a removable strength grade. Just make sure the grade you choose is rated for the heat it will be seeing.

Anyone have a count on the OZ head intake mounting fasteners? I'd use that as a guideline for size and number of fasteners. Jump on the FSPP site and look at the intake gasket kit for the OZ head- count the holes if there's a picture.


--mikey

 

[LameHoof65]

Thanks for the info, that helps a great deal..Any ideas on what type of aluminum would be good for fabricating a manifold adaptor?

 

[godheadcustoms]

I like 6061 aluminum; cuts easy without being "greasy" or "plasticy", nice balance of ductility and strength, easy to find. As long as you're not trying to bend it all over the place (I can't imagine why you would) it works pretty well for most applications.

 

[LameHoof65]

Thanks, how about handling the heat from the exhaust, any potential for warpage? And if not what kind of place would carry it?

 

[Anonymous]

Aluminum expands at twice the rate of steel/iron under heat. Best thing to do would be to try and shield the intake from the heat of the exhaust.

Summit sells some thermal barrier sheets of various flavors. I'd try using somehting like that on the underside of the intake. Header wrap has it's own problems, so I'd recommend against it. Jet Hot coating the header/exhaust manifold will also help keep the heat in, and keep the engine compartment cooler.

--mikey

 

[godheadcustoms]

Like Mikey said, you could run a heat shield between the two as long as you can maintain at least .25" (.5" or more much better) of airspace between the parts. Warpage shouldn't be a problem at all, and heat transfer shouldn't be any worse than the log, hopefully much better in fact. I would try it without a heat shield first, and if you run into problems, it's easy to add one afterwards. You can buy 6061 at any metal supply shop that carries aluminum.
Jet hot coating would be the way to go for a variety of reasons.

 

[LameHoof65]

This helps alot, but my initial plan was to bolt a solid aluminum plate to the surfaced exhaust ports & intake plenum so I could have supporting studs on one adaptor face for both the intake manifold and exhaust manifold. But it sounds like I need to consider two pieces, an aluminum piece for the intake and a steel piece for the exhaust---or perhaps make both out of a solid piece of steel?? and if that is the case what type of steel, cold rolled, carbon, 1040---I haven't a clue :roll:


Mikey, just went to your post on Hardcore tech regarding this---so I guess I need steel, when you say mild---I need numbers and specificity regarding "mild". Sorry, I just ain't metal literate! :

 

[Anonymous]

For the exhaust, I was specifically thinking of Weld Els. They're cast steel pipe bends, for want of a better term. Corky Bell recommends them for fabbing turbo headers in "Maximum Boost."

I don't have the info in front of me. He gives specifics on gage size, etc. I'll see if I can find them at home tonight. Also, you could google search for "turbo header fabrication" and possibly turn up some resources.

SDS fuel injection has this on their site about turbo header fab. It might be of use for your fab project.

http://www.sdsefi.com/techheader.htm

hope this helps.

--mikey

 

[twentyover]

Mild steel is low carbon- something like 1018 or 1020. the 10 stands for no no major alloy groups, the 18 or 20 for the fractional percentage of carbon contet (.18 or .20%). Stay away from fancy stuff, you want somthing.

Increasing carbon makes the steel 'harder'- increases tensile, but also increases brittleness. Dumping additional carbon in, and you'll get gast iron- hugely brittle and hard compared to steels.

Usually use schedule 40 weld els- nothing fancy required to weld them.

 

[LameHoof65]

Okay, sounds great, I kind of remember back 30years ago when I was doing machine work that we used a lot of 1020 cold rolled stock and it was pretty easy to machine. So how about a long piece of bar stock, for the exhaust of 1020 steel for the adaptor. The turbo stuff looks great too, I will see if I can find a place that sells both the weldable els and the bar stock. Thanx, this has been a great help. Any other ideas are more than welcome. 8)