Is there a trick to starting a tap? I need to put a helicoil in the exhaust holes of the heads. I already repaired 4 holes with a standard tap but couldn't get the last two to start so I decided to redrill and install 2 helicoils but now I can't them started either. I don't want to remove the head and send it out. Any help or advice is extremely appreciated, john
Are you using the correct helicoil tap for a 3/8-16 bolt? A full repair kit should consist of either 2 or 3 taps. At least a #1 (starting tap) and a #2 or 3 like a bottom tap. You may want to chamfer the hole with a countersink to aid in starting the tap. Cast iron is tapped dry BTW. ws https://www.grainger.com/product/4D...kwcid=AL!2966!3!281733020633!!!g!472883795758!
I used a 25/64 I believe, the kit came with 1 tap, an install tool, and 12 helicoils. I did try to open up the hole slightly with a larger bit. I had to buy the bit separate. I'm going to recheck the proper bit size thanks
Looks like I am using the correct bit size. I only have one tap that came with the kit. Time to sleep on it. Thanks again by the way, beautiful car you got there
Thanks John... I chased ALL the holes on mine when installing remflex gaskets make a shitty job that much easier. The '72 455 with Hooker headers had to be done in place. Make sure you use anti-seize on the bolts! Also used 6 point torx style header bolts which help. ws
Thats a pair @ give or take about 30.00 USD. The are compressed graphite with a little fiber for strength, but if you bend them they will break. Start out with a hole at the front and get a bolt started through the manifold, through the gasket and into the head. Just a few threads will start to line things up. Again, dont force them. Repeat step one at the rear and then work your way up until all the bolts are started. Cleaned holes, bolts, and never seize right? Pull the manifold up evenly and tighten all the bolts (I like to start in the middle) and work out to the ends. Once its pulled up start at about 5 lbs of torque on the wrench; then 15 and finally about 25 or whatever is recommended for YOUR fasteners. I used a 6 point (torx not a hex) style header bolt. Manifolds are a breeze, but headers will take a few French terms to get them all started. The PO evidently had "issues" with gaskets leaking and there was plenty of residue to clean off. A sharp wood chisel and a FLAT 14" MILL BASTARD file cleaned mine up pretty well. Cleaner is always better on gaskets. I only had 1/4 to 1/2" of clearance to get in and clean. The remflex jobs will overcome a lot, but like above, cleaner is better. These dont need retorquing and probably cant be removed for re-use. Make sure youre where ya wanna be when tightening. Over the last 7 years Ive never had to even snug a bolt. Once and done! 5 stars! ws
When the 430 was on the stand I slowly and very carefully removed the headers trying to save the remflex gaskets. backed out all the bolts to where there was 1/4" of play then lightly wiggled the header while using a sharpened putty knife to get between the gasket and header. Once they wer free removed and started working on the gasket to head surface. Ended up getting one off in useable condition and one that might be usable but better safe than sorry. I had an extra on the shelf.
Thats where the bastard file comes in... try to take a few swipes and correct any "gross" imperfections. Is this in the car or on a stand? Manifolds or headers? ws
It's on a stand. I ended up tapping it to 7/16. I just couldn't get a 3/8 or helicon tap started. 7/16 was no problem. I'm just using stock manifolds. Thanks again for all your help, john
