89supra7mgte;1565161 said:
Mmhmm. Jiggle valve up sir.
---------- Post added at 01:14 PM ---------- Previous post was at 01:10 PM ----------
IJ.;1565151 said:
Even when my motor is under 75k and had never been opened up before? Why no matter what?
ARP Head Bolt Issue. Has anyone else experienced this?
- Thread starter MikesFixedRoof
- Start date
Mmhmm. Jiggle valve up sir.
---------- Post added at 01:14 PM ---------- Previous post was at 01:10 PM ----------
Even when my motor is under 75k and had never been opened up before? Why no matter what?
I have had a HG where it was tight enough to keep coolant frm entering the combustion chambers, but the extreme pressure of compression and combustion would indeed push hot gases into the water jacket. An absence of oil 'milkshake' is not a conclusive indication of a good HG.
So when i do pull the head again, what can I do to prevent this from happening again? Im just gona get a gasket from toyota. Should I get new bolts?
Also, Im not sure I trust myself to do the job again. Anyone know of shops with 7m experience in the nyc/ny area?
MikesFixedRoof;1565246 said:
Next time cut the jiggle valve off so all the air can get out quicker.
MikesFixedRoof;1565246 said:
No matter what, it's just part of a correct build, surface the head or block or use a slighlty thinner HG and you end up with the bolts going down into the corroded/dirty part of the block threads and that adds resistance to the bolt and an incorrect torque reading.
hvyman;1565337 said:
Hmm. Will do.
---------- Post added at 06:45 PM ---------- Previous post was at 06:35 PM ----------
IJ.;1565446 said:
I see what you're saying. But just to be clear the block wasn't surfaced and I used an oem gasket. So that leaves what little material the machinist took off the head during the rebuild.
MikesFixedRoof;1565447 said:
Up to you Dude, just telling you how I work and mine don't fail.....
I wish i took some pics of the stock head bolts when i tore down the last motor. Over half of the bolts corroded the top 3 threads and about a 1cm above the threads.
You should always re-tap the head bolt threads so they go in smoothly and dont give false readings when torquing.
You should always re-tap the head bolt threads so they go in smoothly and dont give false readings when torquing.
IJ.;1565455 said:
Im not doubting you at all, just trying to learn. This was the first time I pulled apart a 7m, and Id like to gather all the tips and pointers I missed.
---------- Post added at 09:40 PM ---------- Previous post was at 09:25 PM ----------
:cry:
hvyman;1565500 said:
I wish you did too. :cry: You know i think i remember my stock bolts looking something like that when i took them out. Just out of curiosity do you know if the tsrm says to retap?
Its not in the repair manual because no mechanic is going to risk stripping a head bolt. Granted most mechaincs just reuse the head bolts and think twice but thats why ts hard to find a good shop too.
<-----does his own work.
<-----does his own work.
Im curious what most find after 20K+ mile tear downs.. Do studs and bolts constantly work loose over the years of heat cycling?
grimreaper;1565650 said:
Mine tore down fine each time after an initial 5 cycle retorque and it's why I always push it, ALWAYS had a few back off before the retorque no matter if it's new or old hardware, even on a brand new block and head.
Hey IJ do you follow ARP instructions on going through 5 cycles of tightening and loosening before applying final torque and then after 5 heat cycles re-torque again. (ARP reference below)
Friction
Friction is an extremely challenging problem because it is so variable and difficult to control. The best way to avoid the pitfalls of friction is by using the stretch method. This way preload is controlled and independent of friction. Each time the bolt is torqued and loosened, the friction factor gets smaller. Eventually the friction levels out and becomes constant for all following repetitions. Therefore, when installing a new bolt where the stretch method cannot be used, the bolt should be tightened and loosened several times before final torque. The number of cycles depends on the lubricant. For ARP recommended lubes, five loosening and tightening cycles is sufficient.
Friction
Friction is an extremely challenging problem because it is so variable and difficult to control. The best way to avoid the pitfalls of friction is by using the stretch method. This way preload is controlled and independent of friction. Each time the bolt is torqued and loosened, the friction factor gets smaller. Eventually the friction levels out and becomes constant for all following repetitions. Therefore, when installing a new bolt where the stretch method cannot be used, the bolt should be tightened and loosened several times before final torque. The number of cycles depends on the lubricant. For ARP recommended lubes, five loosening and tightening cycles is sufficient.
gaboonviper85;1565618 said:
Your douchebag comment wasn't necessary. A simple "no" would've been enough.
---------- Post added at 02:10 PM ---------- Previous post was at 02:03 PM ----------
grimreaper;1565650 said:
I was pretty surprised how tight my original stock 58ftlb bolts were when I took them out...