stripped out cam caps

[silvia s14.5 rb25det]

I was putting the cams in on my ka and started to torque them down. I started with half the spec all the way around the cylinder head. a few of the caps couldn't even hold that and stripped out. I used the manufacturers torque spec. Torqued the rest of the caps down. by the time I was finished 7 bolt holes were stripped out. previously I had the head taken the a well known local machine shop called T-Hoff for resurfacing/ cleaning and they checked the rotating assembly with caps and cams.

The first solution my friend and I thought of was to heli coil it with the same 6x1 size as the bolt. The heli coil (6x1) is almost 2 millimeters larger in diameter than the hole, which is normal for a 6x1 heli coil. but on the Ka24de the clearance between the cam journal and the hole is about 2 to 2 and 1/2 millimeters. so basically the drill bit used with the tap with the 6x1 heli coil would over bore the bolt hole into the cam journal. the next solution we thought of would be to get a smaller but same thread pitch heli coil like a 5x1. I couldn't find a 5x1, but there was a 5x.8 heli so then we thought well maybe we can dye the bolts down to a .8 thread pitch. but dyes are not normally used to make threads rather than to just clean threads. i tried the 5x.8 but they literally just drop into the 6mm hole. and you can't get new bolts because the original bolts are locator bolts. trust me unless these bolts can be custom made the it's not happening. The only other options I could think of to fix this problem would be to sleeve the holes, but that raises the question of how are you going to lock the sleeves in? Or fill, drill and re tap the holes or just get a new head. Yes I know they are cheap but I have put money getting this S**t machined. I have taken a trip back to T-hoff and talked to the guy that serviced the head and he basically told me what i was thinking.

so is there anyone out there that has had this problem and has fixed it successfully without getting a new head?

Modified by silvia s14.5 rb25det at 3:27 PM 5/30/2009
Modified by silvia s14.5 rb25det at 3:33 PM 5/30/2009

[silvia s14.5 rb25det]

come on master techs i know you're out there

[480sx]

If that many of your cam caps are stripped, you might as well get a new head. What are you torquing them to?

[silvia s14.5 rb25det]

the spec is 6-8 ftlb and i started them out at like 3.5 all the way around then went back over them with the other half. it was about 7.5 ftlb when i was done. i talked to a cylinder head specialist that's been in doing heads for about 35 years and he said he has actually put a 6x1 heli coil in a Ka24de before and it worked fine. but i just want to see if there's anything else i can do or just hear a few more success stories with the same problem before i go ahead and drop the 6x1 in.

[silvia s14.5 rb25det]

the guy at T-Hoff said he has never really used exact torque specs on cam caps and that usually they can just be hand tight.

[lptimmy]

i was recently doing a head gasket job at work, and also stripped ot to caps. i was sweating some bullets. my solution was to heil coil them and i had the master tech above e help assit. our kit was also bigger that stock but they worked fine and torqued down just be sure to be super careful with the drill.

[liquid_cool]

the spec is 6-8 ftlb and i started them out at like 3.5 all the way around then went back over them with the other half. it was about 7.5 ftlb when i was done. i talked to a cylinder head specialist that's been in doing heads for about 35 years and he said he has actually put a 6x1 heli coil in a Ka24de before and it worked fine. but i just want to see if there's anything else i can do or just hear a few more success stories with the same problem before i go ahead and drop the 6x1 in.

ok..your mistake is thinking there foot pounds...its not..its inch pounds..its totally different..120 inch pounds is the same as say 4 foot pounds..now..you can fix those threads by having a skill'd welder weld some extra meat on the journals, then drill out and helicoil em...other than that..you best get dealing for a new head...and this time sire..dont rush the job...read carefully..and get an inch pounds torque wrench.

[guyaverage]

Good grief you guys take the hard way out..... Stick a 1/4-20 tap in there, twist it back and forth slowly, down about 1/2 inch or so. You dont even need to drill it first. Wrap a paper towel around the hole, blow some carb cleaner down there to get the metal flakes out. Go to Home Depot, get some 1-1/2 inch 1/4-20 bolts, and torque them to 8 lb ft (the factory spec in the Nissan manual is 6.7-8.7 lb ft). You could do every cap and still not spend $5. Been there, done that 5+ times.

[silvia s14.5 rb25det]

in ftlb 6-8 is the spec for the cam caps. no mistake here

6-8 ftbl is hand tight.

you take a foot pound number and multiply it by 12 and you got inch pounds. and yes i have an inch pounds torque wrench.

I will have enough ASE's in a year to work anywhere I want.so don't be posting dumb sh** on my threads.

I would not recommend to anyone that has the money to spend it on a welder to fill the holes. when you can just get a new head. theres no need for a welder to fix it anyways. I did exactly what the guy before you posted because it was my first idea. and it worked just perfect. i just wanted to see if anyone had done what i was explaining earlier.


Modified by silvia s14.5 rb25det at 12:43 PM 7/24/2009

[motoman399]

plus if you welded it you dont get the 1/2 to 3/4 depth. and you can warp the cam journals. no one wants that

[silvia s14.5 rb25det]

liquid_cool. hahahaha read my post carefully and then look at my motor and try and tell try to me I'm rushing the job.

[liquid_cool]

liquid_cool. hahahaha read my post carefully and then look at my motor and try and tell try to me I'm rushing the job.

well your an a**..i gave you a choice you allready knew about...hence my sarcasim in the post..you are allso baiting for an internet fight!..that shows how cool you are!..what ever man with your ASCE crap..no one cares..if your so skilled..then why did you screw it up in the first place!..dont be a dushbag and try to flame someone who just gave you reallity with fun sarcasim..and your engine!..i havent seen it..and i dont care..if you built it the same way you did your head!..then it s destined for fail.,..good luck with what ever you do.