The P71 is busted. Blew one of the spark plugs clean out of the head. Man I loathe these stupid Mod Motors...
Anyways, does anybody know if this can be successfully fixed with the head on, or is it time to DOHC swap this pig? Oh, it broke the damn coil too, so I need one of those as well. They always break when the income stops...
That totally sucks.
The bad news is that you'll likely have to pull the head to do it right.
The good news is that you have plenty of extra time on your hands to do it.
If the threads are blown out I can't imagine fixing things with out at least a little drilling and tapping.
That means metal shavings, I can't imagine that being a good idea in an assembled motor.
It's fixable with the head on, check out this GRM Tech Tip http://grassrootsmotorsports.com/tech-tips/52/
Speed Junkie
doh.
spending money I don't have to buy parts I don't need to impress people I don't know
ls1 time
i just got my 4.6 running right.
i've repaired plug holes via drill/tap/helicoil with head on engine. drilled, vac with small hose down plug hole, tap coated in grease to catch shavings. fyi the cheapest standard brand coil from rock auto was $27 less incl shipping than local and made in USA, just did #6 again replacing the taiwan coil from advance that i installed when i got the car 2 yrs ago
John Brown wrote:"Safety" is my second middle name, it's right after "Screw".
patgizz wrote: ...tap coated in grease to catch shavings.
If you do it without pulling the head, this is the best advice.
I remember something about lowering the piston and filling the cylinder with shaving cream, do your metal work, then when you roll the engine over it will push the crap out.
Joey
Joey "all you are to me is talking ballast" Blatchford
Your local NAPA has a repair tool and "insert" kit for this, It isn't cheap but it is cheaper than pulling the head. Comes with a special tap, helicoils, installer and a handy blow mold case because you WILL need it again!
Internationally known as The Brown Stig
I've done the shaving cream trick, followed by a vacuum. Worked like a charm on the Sidekick!
i can't wait for mine to blow one so I can justify trickflow heads.
spending money I don't have to buy parts I don't need to impress people I don't know
belteshazzar wrote: i can't wait for mine to blow one so I can justify trickflow heads.
P71, do this!
What vehicles and models are suceptable to this? Any way to stop it from happening?
I worry about reincarnation. What if I’m not hung as well next time around? The Buddha said Not to grasp- life is transitory. Damn it some things a man gets used to grasping.
5.4 swap?
too many cars, not enough time
I have one of those NAPA rethreading tools. You know what a tap looks like, right? A bottoming tap has a flat bottom to get to the bottom of a blind hole, a starter tap has a point to help get things started.
This thing is a starter tap with a longer point which has a cutting surface like a reamer. Align it over the hole and gently turn; it cuts, it threads and it's wonderful. It cuts the spark plug hole oversize and then you install an insert, it's a threaded nipple with spark plug threads inside and threads outside that match the ones you just cut. A little Lock-Tite and you back in the game.
This is a 10 minute job that's only scary if you haven't done it before, nothing to it.
Dan
BMW -- You don't need a hibachi to cook rice.
Dan,
Do you have the part #'s for the tool and insert?
Michael Pinto - 73 AMC Hornet / 93 Miata STS / 01 P71 Interceptor
If the NAPA guy doesn't know where it is he should be looking for a new job ;)
I will check my catalog after I cook lunch (I need to go to the storage unit to get the catalogs)
Internationally known as The Brown Stig
porksboy wrote: What vehicles and models are suceptable to this? Any way to stop it from happening?
2-valve ford mod-motors.
there's like three threads for the plugs, or something equally ridiculous.
spending money I don't have to buy parts I don't need to impress people I don't know
I ordered one of those ridiculous fix-it kits, a plug, and a coil. Keep yer fingers crossed...
Michael Pinto - GoKart / 93 Miata STS / 01 P71 Interceptor
Time sert is the kit the pros use.
And yes, it is one of the two stupidest things ever done to an engine.
The other stupid thing is the plug design they changed to afterwards.
Find a crapped out Mark VIII and swap the motor.
If I had a signature I would probably put it here.
What’s your favorite British sports car?
Triumph
MG
Austin Healey
Aston Martin
Jensen / Jensen Healey
TVR
Morgan
Check back soon for the next poll. View all polls
Built for the true classic car enthusiast, each issue of
Classic Motorsports features profiles on popular as well as unknown classics, along with comparison tests, useful technical articles, buying guides, personality pieces and more. Learn more about us.
Try the next issue free or vist the site.
