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Closed chamber heads straight swap from open?
#1
Hi Guy's

I picked up a set of complete Closed chamber heads, DOAE , I currently have a 72 block with open chamber heads, My question is is it a straight bolt on swap from open to closed chamber heads? Should I get new head bolts or am I ok to reuse my old ones? I Already have a complete gasket set with new head gaskets. Fel-pro.

Since they are not installed yet I'm at least going to put in new valve seals Now rather than waiting to find out later. I need to swap over my Studs Guides and harland sharp rockers. Are there positive stop valve seals available? instead of the umbrella type? The gasket kit I got for a 89 302 had both types I liked the press on style with the collar.

       
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#2
If the bolts and threads look good I always reuse. Had gotten positive stops and had trouble installing them. Not sure if they stayed in place and are working. I Would use umbrella next time if there room.....
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#3
I would opt for new head bolts as cheap insurance. Nice score on the heads!

73 Grandé H Code. Headman long tube headers, T-5 Transmission, 3.70 Traclok, Lowered 1" all around, Aussie 2v heads w/ 2.19 intake, 1.71 exhaust, screw in studs, full roller cam 608/612 lift 280/281 duration LSA 112, Quick Fuel 750 CFM double pumper, AirGap intake.

- Jason


[Image: 082-hot-rod-power-tour-2017-1970-1970s.jpg]
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#4
On an engine with unknown history I prefer to use new bolts, even though it is generally acceptable to reuse them.

Other things you need to consider is having hardened valve seats installed, valve guides, and replace the stock two-piece multi-groove valves with one-piece valves. Have the machinist machine the guides for the good seals and check the mating surfaces for straighteness and touch up if necessary.

Check your cylinder bores for taper and ridge. Worn cylinders and/or worn rings will allow more blow-by with the increased compression.

If the pistons are dished and not flat tops you will not realize the full benefits of the quench heads.



“If you can't explain it simply, you don't understand it well enough.”
--Albert Einstein
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#5
I went with the ARB studs. A bit overkill but I like studs vs bolts. I am able to install and remove the heads with the engine in the car.

'Mike'
73 Convertible - 351C/4V CC heads/4bolt/forged flat tops/comp 270/rhodes/mallory unilite/tri-power/hookers/glasspacks/c6/3.50 limited slip/Gear Vendors/Global West sub frames, strut rods and shelby style traction bars/ Rear sway bar/tilt steering (not original)

Pics of modifications included in:
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#6
Don C;283302 Wrote:On an engine with unknown history I prefer to use new bolts, even though it is generally acceptable to reuse them.

Other things you need to consider is having hardened valve seats installed, valve guides, and replace the stock two-piece multi-groove valves with one-piece valves. Have the machinist machine the guides for the good seals and check the mating surfaces for straighteness and touch up if necessary.

Check your cylinder bores for taper and ridge. Worn cylinders and/or worn rings will allow more blow-by with the increased compression.

If the pistons are dished and not flat tops you will not realize the full benefits of the quench heads.

My Motor is still fresh less than 3000km since it was completely rebuilt so the bottom end stuff should be good. Block was decked and my open chamber heads also. Are the hardened valve seals a MUST? Since my motor is still complete I think I'll leave it alone for now and get these heads built properly before doing the swap. Or just offer them with the car if I ever sell it.

Thanks
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#7
   
83slimer;283310 Wrote:
Don C;283302 Wrote:On an engine with unknown history I prefer to use new bolts, even though it is generally acceptable to reuse them.

Other things you need to consider is having hardened valve seats installed, valve guides, and replace the stock two-piece multi-groove valves with one-piece valves. Have the machinist machine the guides for the good seals and check the mating surfaces for straighteness and touch up if necessary.

Check your cylinder bores for taper and ridge. Worn cylinders and/or worn rings will allow more blow-by with the increased compression.

If the pistons are dished and not flat tops you will not realize the full benefits of the quench heads.

My Motor is still fresh less than 3000km since it was completely rebuilt so the bottom end stuff should be good. Block was decked and my open chamber heads also. Are the hardened valve seals a MUST? Since my motor is still complete I think I'll leave it alone for now and get these heads built properly before doing the swap. Or just offer them with the car if I ever sell it.

Thanks

All good recommendations by Don, in fact I followed his advise when I had my heads done. Concerning the harden valve seats, the machine shop said he didn't feel they were needed but I went ahead and had them done anyway.

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Jim

M code 71 Mach 1, 351 4V Cleveland, Ram Air (not factory), C6 Trans, 3.5 rear
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#8
Valve recession with unleaded fuel is not a myth. I've had it happen on FE and Y block heads. The FE was much worse even though it wasn't driven much, it was a '70 engine.

So, yes I consider it a must, it was the first thing I did when I acquired my '71 Mustang.



“If you can't explain it simply, you don't understand it well enough.”
--Albert Einstein
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#9
Either way on the head bolts new or reuse be sure and run a tap in all the holes and blow them out good. DO NOT use assembly lube on the threads or Molycoat. Use what the mfg. of the bolts recommends if new and just light oil if the old ones. Assembly lube and Molycoat tend to over torque the bolts being slicker.
I have never had any fear of not having hard seats myself. Ran one Y block for for almost 100,000 miles and it never had anything but Pure White gas or unleaded in it. Just parked it in the barn never had the heads off. As far as the two piece valves breaking, don't float the valves and bend them and they won't break. Timing chain goes and you bump the valves and you don't change them then they are likely to rock and break head off. Huge valve spring pressure will also snap them but stock cam with stock springs won't be and issue.
If you are racing and running really narrow valve seats with triple angle valve job then the valves are going to beat in or recess down sooner also.
Most of us are not racing just going to shows and cruising around and no need to panic and try to squeeze 2 more HP out of the engine. I would love to sell you guys insurance. I don't even have homeowners.
Check the heads over, spring pressure, height, seats and guides, fix what is needed change the seals and enjoy your toy. Spending lots of money on racing stuff makes your engine not last as long as stock.
My opinion and I support this message, lol.
Been sanding drywall all day so I am grouchy.


When a man is in the woods and talks and no women are there is he still wrong??
Tongue
David
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#10
Sometimes after adding up the cost of rebuilding heads say new harden seats and guides/stainless valves and so on, you paid for a new set alloy heads that flow and perform as good and better as factory iron. I seldom get new bolts unless there a reason, last dyno was a year ago was 389.6 hp to the tires at 6325 rpm's max torque 382.7 at 4580 rpms. So that puts it's about 448.0 at the flywheel. Not to bad for factory CC heads and a very mild street cam that's been driven twice across country to the left coast and back to PA. and other trips with 30 thousand miles total and 10 yrs now. Sometimes we just over think and over do what really need if we are on a tight budget. Butt that's just my opinion. Imagine what today's modern more advance alloy heads could do for a bit more money.... I guess I better shut up before somebody gets mad.....
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