HD headstuds

[hondaREX]

Those that did the GT Thunder HD headstuds themselves, did you use the suggested Permatex sleeve retainer? And did you use a regular tap or did you have to use a bottoming tap?

I measured the stud holes and believe i can get away with a regular tap. And besides good insurance, do i need them with a 86mm 11:1 piston? Im pretty good with jetting and have a spal fan and oil temp dipstick so i dont ever let it currently get hotter than 210. Just on budget and looking to save a buck where i can, if i can. thanks

[slightlybent47]

I have a 07 with 12.1 piston and board to a 416 and have had zero problems with the stock studs, it in over 4 years of hard racing. Still solid as a rock and running just fine. I’ve been told the trick is in how you torque the studs. The guy that built mine said you need to torque in progressive steps till you get the recommended lb’s. Most try to over torque them and that’s where you get problems with then pulling out and causing a head gasket leak.

[DragonGunner]

I ran stock studs on several builds, with 11:1 that ran perfect for yrs....not until after alot of tear downs and a 440 12.5:1 did they finally go.

[riotact]

Dont use a regular tap,you need a roll form tap for those studs.

[CJM]

Originally posted by riotact
Dont use a regular tap,you need a roll form tap for those studs.

I used to think so, but a friend had his studs done by regular tap and has had no issues.

[hondaREX]

So if i re-use my stock studs, should i use the Permatex sleeve retainer that GT Thunder recommends for their HD studs when i re-install them? That crap is hard to find and isnt cheap.

[CJM]

I would.

Personally you dont have to do the studs, but for the cost its worth it as piece of mind just incase.

[gasguzzler]

I used the green Hondalock 3, which I believe is basically the same stuff.

[riotact]

Originally posted by CJM
I used to think so, but a friend had his studs done by regular tap and has had no issues.

Sweet that will save some money then.

[AtvKid4Eva]

Its hit or miss. Ive seen bikes with one rebuild on them leak because of the headstuds, ive also seen bikes with multiple rebuilds not leak with the stock headstuds. Its relatively cheap so i would just get it done by GT Thunder.

[JOHNDOE83]

I havent had any HD studs installed on my 440, its over 7 years old now, it slightly leaked before the 440 then never leaked until recently. Further investigation leads to needing a new gasket.

HD studs arent needed but are great for the "what if" scenario, If you dont torque to factory specs you wont ever stretch a head stud, stretched studs arent from 440 big bores, they are from higher compression and over torqing.

Although HD studs arent 100% needed, now that I look back, I wish I had installed them in mine the first time I took it apart.

For the price, its a upgrade you really cant pass up when you already have it apart.

[CJM]

I agree with John. Not needed but worth it just incase for the cost.

I think the main reason so many have issues is they overtorque the studs or inherited someone elses issue.

[hondaREX]

So CJM, when you say your buddy had is done with a regular tap. Do you mean a regular full length tap or a bottoming tap? I plan to have the bike for awhile so im probably going to do them myself. Have plenty of regular taps but no bottoming.

Off topic CJM, but you have had most bore sizes. Should i skip over the 407cc and go for the 416cc or 426cc 11:1s? Or will i be pleased enough with the 407cc 11:1? The bike got 10 years on the stoke bore. And i am all about going one bore at a time but if the 407cc 11:1 isnt going to be noticeable, then i want to go bigger.

I will have a full Sparks, HC stage 2 and the piston that i didnt have when it was stock, so all together it should be great at 407cc. But an opinion from someone who has ridden them all is appreciated. Thanks.

[DragonGunner]

It was my understanding that it was the heating of the motor that helped to stretch the studs. The longer and hotter the motor got over time indeed stretched the studs. Just what I had read over the yrs. The HD studs are made thicker for this reason, so as to be stronger and reduce the amount of stretching.

[CJM]

@Dragon: this is true, improper jetting heats up the exhaust ALOT. Well the exhaust is mounted right on top of the stud. Heating up AL alloy the topend is never a good idea.

Honestly the bore size really doesnt effect it much. Gives you a bit more lowend torque but if it was more than 1 ft-lb Id be surprised. Compression is power not bore size. Thats why some knucklehead with a 440 10:1 comp is easily beaten by someone with an 11:1 416 in most cases. Also, the smaller bores rev up much faster and better imho.

My buddies 407 pulled really nice, if anything it has just as much power as my 426-were dead even mod wise. my buddy does weight about 75lbs more than me tho. And you also must take into account my build is over a year old now and has alot of hours. Another friends 416 I helped with pulled pretty much dead even with my 426.

Im not sure what the deal is, but ever since I went to the 426 I have had bad vibration issues. I assume either A) The wiseco piston is junk and maybe heavier than the 416 wiseco I had or B when i sunk it in a lake 2 years ago I mighta bent the rod (yet it keeps on trucking so IDK).

Bore as little as possible imho. Even 402 might be worth it. At this point I can either do a 440 or go back to square 1 cause its burning oil (I guess riding hard for at least 75hrs a year puts alot of stress on stuff lol. I hardly ever get more than a year or two out of a bore).

Anyways, Id do a 407 as its just an easier piston to find. Buy a quality piston like a JE or CP-wisecos ok but not great after having run a few of them.

If your gonna build the motor for absolute power you need to do the 450r carb, stage 2 hotcam, full (or at least a good slip on) exhaust, open lid and gear it right. Vs a stock 06+ 450 I would lose or maybe win by a quad length (Im also not a very good drag racer) in a drag b/c they have more power stock than I do worked (I never dynoed the 400-I had to guiess Im making about 35hp +/- 2-3hp at the absolute most).

[CSR400EX]

Originally posted by hondaREX
[B Do you mean a regular full length tap or a bottoming tap? I plan to have the bike for awhile so im probably going to do them myself. Have plenty of regular taps but no bottoming. [/B]

Ive used a regular tap, but i had a machine shop drill and tap the holes just to ensure that everything was done straight. Also have had the roll forming done but the shop charged me an arm and a leg to do it cause i had to buy the tap, which isnt cheap. All in all i got great results with either or.

[Ruby Soho]

i had an 11:1 440 pop 3 times before i put studs in. after the studs i put probly 300hrs on it no issues.


hit or miss, for the price.... do it.

[DragonGunner]

CJM... agree 100%....I also ran 416 and 428....didn't have any vib on the 428....but that was several yrs. ago and who know how quality control is from yr to yr with the piston makers...? I have a 407 (or 406) the last 7 yrs or so and its just as fast if not faster than all the above including a 440 12.5:1 that was short lived.


Hows your job holding out by the way?

[CJM]

Runs well but its time for a rebuild as its started to smoke.

Like I said earlier as well, Im not sure if perhaps something is indeed messed up in the engine as it runs well-but in the last few months I have noticed the ticking from the cam is louder (everything seems to be in spec) and overall the 426 vibrated more than the 416 or my buddies 407.

When i do rebuild Im doing a high comp stock bore probably. Just press a new sleeve in and a piston and Im done.

[Wheelie]

I sent my cylinder off yesterday for head studs, they finally went after 5 years. 11.3:1 compression and advanced timing was the culprit for the death of the stockers. Cylinder looked great, just going to have it honed.

Figured while it's apart might as well bump the compression to 12.5:1 and add a couple ponies. The rest of the build will stay the same. I'm going to test it with the 4 degree key still installed and straight E-85 with a 245 main.