intake manifold torqueing

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Belgian1979
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intake manifold torqueing

Post by Belgian1979 »

Quid question: always had difficulty getting a proper torque wrench on the bolts of my intake manifold, especially on the 4 center ones. I was thinking on lenghtening it with a 3/8 wrench. One end just fits over the square head of my torque wrench and I could recalculate the torque based on the extra amount of force created when the wrench adds distance. Is this ok to do? When calculating the torque of 30 lbs/ft would become 22 lbs/ft.
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Re: intake manifold torqueing

Post by rp930 »

Use a crows foot.
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Re: intake manifold torqueing

Post by travis »

I'm sure 20 people are going to tell me I'm doing it wrong, but other than GM Vortec style heads/intakes with their straight up and down bolts and very specific torque specs, I've never used a torque wrench on any intake on anything, and never had any issues.
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Re: intake manifold torqueing

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When I was young, tight was good enough but as I got older I try n torque everything(now being able to afford multiple torque wrenches). That said oil, thread sealer, thread locker, anti-seize And crowfeet or I've read excessive extension length & multiple extensions effect torque!

Some by as much as 20% and why also some people don't like the ARP lube, they say it's too slippery(not sure what I'll do with all those sample packets).

Now I've always liked head bolts on a SBC But I finally understood why some prefer studs. After comparing multiple head bolt sets(yes I know this is intake bolts thread But example) since the block holes aren't blind on an oem block you of course should use a thread sealer(my younger self didn't and was ok). Anyways I don't wanna sidetrack too much but many aftermarket SBC heads require sealer on the inner 2(4 both sides) intake bolts because they are thru, so it should be factored when torqued and also if a crowfoot is used. That said some intakes I use a long extension to get em or a crowfoot. But young/past me would just use a wrench for the center bolts, I'd still do them in order, just hand tight em all tho only.

I also like to chase threads these days(mostly in just the block deck), but I wouldn't worry on the heads unless a thread sealer/locker was used prior.
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Re: intake manifold torqueing

Post by BOOT »

Also of course the torque needed depends on the strength of your bolts to achieve proper stretch, young me would just throw in some hardware store shiny gold grade 8 But current me will be happy with with grade 5 or even hardware store low grade SS(at a low torque). [side rant]ARP or Chrome everything bolts don't make your car faster, had to explain this to many Budget friends, save your money n buy go-fast parts.

It's funny how many worry bout proper stretch for rods bolts but nothing else. Just need enough torque to stretch the metal and keep it from backing out. A bolt is a spiral wedge :)

Stronger bolts more torque to stretch, if that parts threads your inserting the bolt into can handle it.
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Re: intake manifold torqueing

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Proper thread length, oh I forgot thread engagement & diff metals :lol:
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Re: intake manifold torqueing

Post by Tom68 »

Belgian1979 wrote: Sat Jan 28, 2023 8:41 am Quid question: always had difficulty getting a proper torque wrench on the bolts of my intake manifold, especially on the 4 center ones. I was thinking on lenghtening it with a 3/8 wrench. One end just fits over the square head of my torque wrench and I could recalculate the torque based on the extra amount of force created when the wrench adds distance. Is this ok to do? When calculating the torque of 30 lbs/ft would become 22 lbs/ft.
You don't need to tighten anywhere near stripping, stretching or breaking point, so you don't need a torque wrench.

What you do need is good feel (lube the bolt head to washer interface) and keep an eye on the end rails to make sure you stay parallel, you can feel the gasket compressing.

If you use a torque wrench you could be distorting the manifold because you are not feeling what's going on.
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Re: intake manifold torqueing

Post by rp930 »

BOOT wrote: Sat Jan 28, 2023 10:41 am When I was young, tight was good enough but as I got older I try n torque everything(now being able to afford multiple torque wrenches). That said oil, thread sealer, thread locker, anti-seize And crowfeet or I've read excessive extension length & multiple extensions effect torque!

Some by as much as 20% and why also some people don't like the ARP lube, they say it's too slippery(not sure what I'll do with all those sample packets).

Now I've always liked head bolts on a SBC But I finally understood why some prefer studs. After comparing multiple head bolt sets(yes I know this is intake bolts thread But example) since the block holes aren't blind on an oem block you of course should use a thread sealer(my younger self didn't and was ok). Anyways I don't wanna sidetrack too much but many aftermarket SBC heads require sealer on the inner 2(4 both sides) intake bolts because they are thru, so it should be factored when torqued and also if a crowfoot is used. That said some intakes I use a long extension to get em or a crowfoot. But young/past me would just use a wrench for the center bolts, I'd still do them in order, just hand tight em all tho only.

I also like to chase threads these days(mostly in just the block deck), but I wouldn't worry on the heads unless a thread sealer/locker was used prior.
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Re: intake manifold torqueing

Post by Alaskaracer »

travis wrote: Sat Jan 28, 2023 9:17 am I'm sure 20 people are going to tell me I'm doing it wrong, but other than GM Vortec style heads/intakes with their straight up and down bolts and very specific torque specs, I've never used a torque wrench on any intake on anything, and never had any issues.
Pretty much how I've done my stuff and a lot of others, except when doing repairs on customers stuff.....and ESPECIALLY plastic intakes...torque wrench all the way
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Re: intake manifold torqueing

Post by FC-Pilot »

Other than the vortec with the plastic gasket, I torque by hand feel. I always start from the inside out, and gently work my way around. Then back to the inside to start over again as the inside will feel lose again. I keep doing that in very small increments until all feel equally ”snug”. Now that is just me, and I do BBC and SBC stuff. If I touched anything else you can bet I put a torque wrench on it. I know how stupid I am so I know I can screw hints up.

Also, this is all my own stuff.

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Re: intake manifold torqueing

Post by treyrags »

Tom68 wrote: Sat Jan 28, 2023 6:02 pm
You don't need to tighten anywhere near stripping, stretching or breaking point, so you don't need a torque wrench.

What you do need is good feel (lube the bolt head to washer interface) and keep an eye on the end rails to make sure you stay parallel, you can feel the gasket compressing.

If you use a torque wrench you could be distorting the manifold because you are not feeling what's going on.
Feel is more important, especially when the clamp is at an angle like a sbf. The surfaces are not only compressing the gasket but also trying to shear it. You can "torque" to a number and come back an hour later and it has lost torque. You can keep tightening it to a "spec" and this will continue until you have squeezed or distorted the gasket too much,
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Re: intake manifold torqueing

Post by Geoff2 »

Edel recommended 25 ft lbs for 3/8" bolts. Important with alum intakes not to over-torque & deform the intake. After bolt tightening, run engine & let it cool down. Re-check bolts. Repeat this procedure until there is no further tightening of the bolts.
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Re: intake manifold torqueing

Post by stealth »

torque extender.PNG
Torque extenders are available... you just reduce the torque wrench reading accordingly.
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