Roadracer Al Posted December 11, 2009 Report Share Posted December 11, 2009 :mad: Somewhere down the line, in the history of my L20 motor, someone stripped the thread out the the #1 plug hole. TWICE. :eek: There were two, count'm TWO nested HeliCoils that allowed the standard plug to thread into the head. I've never seen anything like it. They apparently used JB Weld to hold the whole mess together, in the process, glued the spark plug to the HeliCoil. When I removed the old plug, it backed out the helicoil. I'm guessing that someone butchered up the initial attempt at installing the HeliCoil, and went oversize. I've never seen a HeliCoil fail in service (provided it wasn't badly over-stressed by design), so I don't think it was that. The other thing I can't quite figure out is how they got the thread tapped for the bigger HeliCoil -- it's certainly not any standard size known to me or Google. Maybe that was what the JB weld was for -- instead of a 16.5 x 1.25, they used a 17 x 1.25 tap, which is available, but would leave .5mm of slop. So, I'm thinking I need to investigate Time-Serts. Maybe they'll have something that will work. If not, I'll have to single-point my own insert on the metal lathe (I suck at cutting threads, especially internal threads) and tap a really big thread in the head. Anybody ever see a mess like this? How did you handle it? Oh, and the good news, with 3 new plugs and wires, it fired right up while my wife was bumping the key to get #1 to TDC, spraying me in the face with carb cleaner, JB Weld bits, and HeliCoil bits. Nice. :fu: Quote Link to comment
Smiley720 Posted December 11, 2009 Report Share Posted December 11, 2009 I bat your wife was finally happy to get to spray YOU in face. Lol Quote Link to comment
zerow Posted December 11, 2009 Report Share Posted December 11, 2009 Once again, proof that you just cannot give the common man tools. It goes to show that they can, and will use them in a manner other than directed. Quote Link to comment
Roadracer Al Posted December 11, 2009 Author Report Share Posted December 11, 2009 Smiley, actually, she was pretty concerned since the petroleum shit got in my eyes and hurt like hell, what with me screaming "f*ck! ow, turn it off, ow, ow turn it off f*ck!f*ck!f*ck!" like a school girl. But, yeah, I get the joke. :fu: Zerow, my feeling is that a mechanic did this --- who else would have the two tap sizes, and the two helicoil sizes, never mind the "creativity" do to combine them? I did some web research, Time-Sert, has a variation called the "Big-Sert", which is specifically for cases where some knuckle-dragger has screwed the poodle on their HeliCoil repair and made the hole too big for another HeliCoil. It is 100% the right solution here. The downside is that the installation kit (specialized cutter, big-sert tap, installation tool, and roll-forming tap) is about $100. Seems steep to me. Anyone else in the Bay Area need a spark plug hole repaired? I'll do it for $40 per hole. Heh, that could real easy be taken out of context... :lol: Quote Link to comment
Llittle_Llama Posted December 11, 2009 Report Share Posted December 11, 2009 I got an a80 head I will sell you for 100 shipped, save you some money! email me at dwnshfter@yahoo.com if you want it. Quote Link to comment
dat521gatherer Posted December 11, 2009 Report Share Posted December 11, 2009 this is one of the reasons i hate heli coils. i wish people would just retap the threads to the same size. very rarely do you ever need to helicoil. i mean really how far down do you need to fuck the threads up before you need to helicoil. come on. i hate helicoil!! Quote Link to comment
Roadracer Al Posted December 11, 2009 Author Report Share Posted December 11, 2009 I have to admit I learned something today. The double HeliCoil is actually a commercial product from HeliCoil called, cleverly "TwinSert": http://www.helicoil.com.sg/HeliCoil-Oversize-Twinserts.htm So, I have improved my view of the previous mechanic. I guess I jump to conclusions and think everyone else is stupid or something. :cool: After talking to some machinists, they say that there is no reason to spend all the hard-earned cash on the TimeSert installation kit, that I have or can make easily whatever is needed to make the BigSert work. HeliCoils are clever, and the installation equipment is cheap, but I think TimeSerts are better-engineered, and ought to prove much more durable. Quote Link to comment
lynchfourtwenty Posted December 11, 2009 Report Share Posted December 11, 2009 Smiley, actually, she was pretty concerned since the petroleum shit got in my eyes and hurt like hell, what with me screaming "f*ck! ow, turn it off, ow, ow turn it off f*ck!f*ck!f*ck!" like a school girl. But, yeah, I get the joke. :fu: lol one time my ex's dad drove through some really deep water with his hard body.. so b4 he tried to restart it i took all the plugs out so the engine woudlnt try compressing water, thinkin.. im smart!! hahaha i said "turn it over" and WHAM gas+water right in the fucking eyes! my ex laughed.. so i feel your pain, and then some.. Quote Link to comment
banzai510(hainz) Posted December 11, 2009 Report Share Posted December 11, 2009 dont buy autolite spark plugs. Known to gull up the threads. Sligtly differnt pitch I think. Quote Link to comment
Dime Dave Posted December 11, 2009 Report Share Posted December 11, 2009 Hainz, Back in my air cooled VW Bug days you never used anything but Bosch plugs. Champion plugs were a stick NO NO! The threads on the Bosch plug was rolled, Champion was cut. Putting cut thread plugs in an aluminum head that had used rolled thread plugs was an almost guaranteed stripped thread when it came out. I'll bet Autolight plug threads are cut threads. Quote Link to comment
Dime Dave Posted December 11, 2009 Report Share Posted December 11, 2009 I prefer Keenserts to Helicoils. Same idea as a TimeSert except it has 4 locking "Kees" that get driven down between the insert and the base metal to keep the insert from rotating out. Quote Link to comment
Dime Dave Posted December 11, 2009 Report Share Posted December 11, 2009 Now let me give you a real "backwoods" way of drilling and tapping a sparkplug hole to install a threadsaver without taking the head off. Before you drill out the spark plug hole, rotate the engine until the piston comes up on the compression stroke. Just when the intake valve is 100% closed, stop. Now the real backwoods stuff happens. Fill the cylinder with foam shaving cream. You'll likely need a straw, but spray the stuff right down the sparkplug hole until the cylinder is full. Then drill and tap the hole, install your insert and before you install the spark plug, crank the engine over and squirt out the shaving cream and in therory all the metal chips that fell inside. You can also use wheel bearing grease on your tap to help keep chips from getting inside the cylinder as well. Not anywhere near the correct way of taking of the head off, but in a jam it gets the job done and limits the amount of contamination that can get into the cylinder. Quote Link to comment
lil89ram50 Posted December 11, 2009 Report Share Posted December 11, 2009 Now let me give you a real "backwoods" way of drilling and tapping a sparkplug hole to install a threadsaver without taking the head off. Before you drill out the spark plug hole, rotate the engine until the piston comes up on the compression stroke. Just when the intake valve is 100% closed, stop. Now the real backwoods stuff happens. Fill the cylinder with foam shaving cream. You'll likely need a straw, but spray the stuff right down the sparkplug hole until the cylinder is full. Then drill and tap the hole, install your insert and before you install the spark plug, crank the engine over and squirt out the shaving cream and in therory all the metal chips that fell inside. You can also use wheel bearing grease on your tap to help keep chips from getting inside the cylinder as well. Not anywhere near the correct way of taking of the head off, but in a jam it gets the job done and limits the amount of contamination that can get into the cylinder. wouldnt that leave a bunch of foam in there? theres likely no way of getting it all out...... is there? Quote Link to comment
lynchfourtwenty Posted December 12, 2009 Report Share Posted December 12, 2009 running the engine would burn it out quickly.. Quote Link to comment
hang_510 Posted December 12, 2009 Report Share Posted December 12, 2009 Now let me give you a real "backwoods" way of drilling and tapping ... best use of shave cream since holloween! :lol: i did something similiar on oil bypass valve in the block. oiled 2 'lint free cloths' (from work) and shoved em in the hole. tapped the hole, cleaned as much as possible away, pulled the 1st out, cleaned again, pulled the other out. the guy i sold it to still drives it :D Quote Link to comment
Roadracer Al Posted December 12, 2009 Author Report Share Posted December 12, 2009 I've never heard the shaving cream bit. Sounds interesting to watch, at the very least! I'm down with the grease-on-the-tap routine. Either way, I'm going to tape a length of fuel line hose onto a vacuum cleaner nozzle and stick it down in the plug hole before I install the insert. Quote Link to comment
Roadracer Al Posted January 3, 2010 Author Report Share Posted January 3, 2010 FINALLY... I got some time after the holidays (hope everyone had a great time with family & friends, best wishes for the new year, etc.) and got my insert made. So, after all the bashing of the former mechanic, I went and pulled a DUMBASS MOVE --- I drilled & tapped the head a bigger size than I had made the insert! :angry: (it looks like the new site look doesn't have the "banging head against the wall" smiley) So, I had to make a new insert, twice because I made the first one undersize and it was a poor fit in the threads. So, yeah, I think in the long run, I probably should have just bought the $100 insert kit -- it took me like 6 hours to make the insert work, and $30 for a special order sparkplug tap. Quote Link to comment
HRH Posted January 3, 2010 Report Share Posted January 3, 2010 You know another good tip for getting shit out of the cylinders is to take your shop vac, and put a piece of 1/4 inch vacuum hose or slightly larger in the end, wrap it good with electrical/duct tape, and then you have a super flexible sucker attachment that goes right down into the cylinder! Used that once, though I can't remember why. Quote Link to comment
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