what size tap for header bolt holes

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dexyman
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what size tap for header bolt holes

Post by dexyman » Sun Aug 24, 2014 2:10 pm

made a start to fitting headers and exhaust today.

all was going well

eleven header bolt out no probs one to go

and the bugger snapped. luckily its the rear bolt on passengers side side so i can get in with a drill after moving the blower and aircon stuff out the way

what size tap to i need to buy as im going to drill out the snapped bolt

warlord
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Re: what size tap for header bolt holes

Post by warlord » Sun Aug 24, 2014 6:17 pm

I've just bought new bolts for changing my manifolds, on the back of one of the packets it says:
Contents:
4 bolts 3/8"-16 x 2-1/4"
2 studs 3/8"-16 x 3.43

hope this helps
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SUPERCHARGEDGTA

Re: what size tap for header bolt holes

Post by SUPERCHARGEDGTA » Sun Aug 24, 2014 7:29 pm

3/8 - 16 (3/8 dia. 16 teeth per inch) is 3/8 UNC
this is the tap you need

dexyman
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Re: what size tap for header bolt holes

Post by dexyman » Sun Aug 24, 2014 7:34 pm

cheers

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bhm1712
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Re: what size tap for header bolt holes

Post by bhm1712 » Sun Aug 24, 2014 9:35 pm

Have you considered trying an easy out first and plenty of penno fluid?

I've not had a snapped bolt stuck for long with that method. Might save you time and heartache
Ian Hopkinson - Membership Manager & Forum Administrator
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dexyman
POC Newbie
Posts: 77
Joined: Mon Jun 03, 2013 7:53 pm
Year: 1990
Model: Trans am
Engine: 305
Name: Derek Wright
Location: Lochgelly
Contact:

Re: what size tap for header bolt holes

Post by dexyman » Wed Aug 27, 2014 7:23 pm

appears i have been lucky . managed to get a bit time today and removed the rest of the exhaust.

i thought id offer up the new headers. looks like drivers side ill need to disconnect the steering to get it in BUT the passengers side pretty much fell in AND the bolt i snapped isnt used on the new headers as there was another hole which must have beed under the old manifold which is in the correct place

strange i though but result anyway.

i did however snap my oxygen sensor wire and it looks like i need a new sensor which is on the passengers side cylinder head down by the headers

Are the universal oxygen sensors ok to use and what is the sensor in the head so i buy the correct part

SUPERCHARGEDGTA

Re: what size tap for header bolt holes

Post by SUPERCHARGEDGTA » Wed Aug 27, 2014 9:39 pm

must be a common thing, had the same thing on one of ours (davids I think) broke a bolt off in head and put headers on to drill through, and like you, found out it was not used/needed

the sensor in the head is temp. sensor for ecu I think

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