1500 10 bolt head studs

tigeravg

tigeravg

True Classic
Asked before, I know. However i'm gonna ask again. Anybody have a good part number for some ARP 12mm studs of the correct length? Thanks in advance.
 
Thanks Jeff. I have eaten three head gaskets. Turns out my new head is warped a bit. Spec is no more than 2 thousanths. Mine is 2.5. Having my machine shop take 1.5 off and going to use a thicker "racing gasket". Also going to have my cam driven dizzy re curved to have all the advance in by 3000-3500 per Matt. Then tune from there. I too have evidence of detonation (fire ring pushed out) despite backing off timing. Thanks again for the link.

Dr.Jeff said:
See if anything in this thread will help:
https://xwebforums.com/forum/index.php?threads/head-stud-conversion.36756/[/QUOTE
Click to expand...
 
Are you sure your guild pins are not too long, and that your head bolts also are not too long?

It is easy to check when you have it all apart.

measure how much guild pin you have showing and make sure there is enough room in the head for that.

Run the head bolts in until they touch bottom and measure how much bolt you have between the block and the bottom of the bolt head.
Then put a bolt through the head and measure how much threads you have sticking out.
Then do a little bit of math to make sure your head bolts are not too long (and bottoming out before you fully clamp the head)

When I did the head rebuild on my wife's car I did that and could see with much machining on the head, and any variance in the head bolts, I could see this causing an issue.

And you know about re-torquing the head? a few heat cycles (full temp and cool down) re-torque. then a few hundred-ish miles re-torque again.
 
Rod makes good points.

Is the reason for wanting a thicker gasket to try and improve it's sealing capacity....the logic possibly being it will crush more to fill any low spots better? Or are you looking to lower the compression to reduce detonation? I don't recall if you already have an increased compression ratio? I'm not sure the first scenario will happen. It could actually be weaker. The second scenario may work, but a MLS would be a better approach for that in my opinion. I found the MLS gaskets to be no more expensive than the "racing" gaskets. Just food for thought.
 
Thicker for improve sealing, partially because the deck has been shaved a rediculous ammount and I actually need valve clearance. And, for the fact that there are two low spots I am concerned about...even when I have another 1.5 thou skimmed off the head. As for checking the bolt/stud depth...done it. As for retorque, done it too. I tend to believe my bolts are streched to **** (original?), and fuel starvation conspired together to essentially cause detonation "pushing" of the fire ring(s). Going all studs (ARP) should take care of any torquing variences. My compression is as high as decking could make it. The car ran incredible before it ate itself, with power immediately from the loud pedal all the way till I ran out of fuel/balls
 
Also don’t overlook the two locating dowels. They can bottom out if the head and block have been skimmed.
 
Did you clean the head bolt threads in the block? They can get seriously gummed up and give false torque readings. I had a spider motor do this, clicked the torque wrench at the prescribed torque and the head bolt washer was still loose. Anytime I pull a head, I chase the threads, use an old head bolt with two vertical slots cut in it to make it a thread cleaner as a tap is too aggressive. Also make sure on blind head bolt holes that the bottom of the hole is not full of crud.
 
I don't recall what type of induction you have - FI, or dual Weber carbs, or single carb? But with the high compression you have, air:fuel ratio can be critical...especially with the non-standard distributor and ignition advance curve you mentioned. Sounds like you are already addressing most of the variables; advance curve, head surface, gasket, etc, but have you verified your AFR? Maybe think about installing a wideband O2 or having it dyno'ed to make sure you can't run lean again.
 
Yup Jeff. An O2 sensor is recommended by Matt as well. Might have to go that far. As far as chasing the threads...BTDT. I am somewhat fanatical about threads and surfaces being crazy clean. After chasing, I cotton swab them all the way to the bottoms, often going thru dozens of swabs...Not even borderline OCD.
 
Sounds good. There are a couple of wideband O2 sensors that are more affordable that most and seem to get good reviews. Considering you don't have a computer controlled EFI, where the AFR signal is more critical than with carbs, I'd be inclined to get one of them rather than a top of the line name brand. Frankly, even after considerable research, I have not found any evidence (perhaps I should say 'scientific evidence') that any of them are significantly better or worse than the others. Here are a couple of the ones I'm referring to:

https://www.14point7.com/

https://www.wide-band.com/
 
If you want to go real cheap, use an oxygen sensor used in a fuel injected spider or X and a digital voltmeter. That's how I set up the jetting for the IDFs I had on a spider years ago.
 
Although not quite as affordable as using a multimeter, you could get a very inexpensive narrow band O2 gauge to connect to a standard O2 sensor. That way it can be mounted in the dash to monitor under different driving conditions to help sort out the jetting. Narrow band (either by multimeter or gauge) is slow to react, so you have to watch it as the condition persists for a while. But for carbs it should be enough for you to jet it. FI requires the faster response of a wideband O2 to get the mixtures correct, but that is a complete different game; carbs are vague at best compared to a ECU, so a narrow band can work reasonably well. It will indicate a very general "too rich" or "too lean" condition as you try different jets, something of a trial and error method.
 
I thought all Bosch L-Jetronic FI (used on Fiats) have a narrow band sensor. One can get in a real bad habit of staring at an O2 sensor while driving, to the point of not paying attention to the road. After I have my jetting set, I remove the gauge/voltmeter.
 
carl said:
I thought all Bosch L-Jetronic FI (used on Fiats) have a narrow band sensor.
Click to expand...
That is correct, but it isn't used to tune the overall mixture like needs to be done here. On the Bosch system the mixture program has already been determined in the ECU, so the O2 is only making very fine adjustments at idle to help with emissions regulations. The ECU's program to adjust the AFR isn't changed. With a aftermarket ECU the entire mixture program (base map) needs to be established. A wideband O2 is used to do that. In the current situation of jetting his dual Webers, it is much like establishing the baseline program for a aftermarket ECU (when the carbs are first installed). So a wideband O2 would help to get there faster, but eventually he can do it with a narrowband O2 because carb jets are very basic mixture changes compared to those of a ECU.
 
OK, I got tired of just thinking about it so I ordered a set of ARP studs, 207-4201. I will give an update on what exactly has to be done to use these. I have already been given some great info by several members. I also sent the cam mounted distributor off to be rebuilt/recurved. Using a guy in Anaheim for this. We talked on the phone for a bit and he seems to know what he's doing around a Sun Machine. Price seems pretty reasonable too. I'll report in when I get her all back together.
 
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