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Anyone know the torque specs offhand for ARP headbolts? This is with the cometic MLX HG. I’m at the shop trying to double check on my phone. Having a little trouble with it. Thanks in advance
Thanks SNLC, wanted a confidence check. Trying to find OTRAM's vid with moly fingers on a smartphone, not so smart. Much appreciatedI went 80ftlbs.
Cheers
Steves Machine Shop in Azusa, CA.Who is doing the head work for you? I have debated doing something similar for a long time along with a good header/exhaust setup. Just get it to breathe a bit better for the extra little bit it needs to be satisfactory. I don't have any idea for ARP stud torque but maybe call ARP and see what they recommend?
Thanks much appreciated 80ft/lbs for the OPEL ARP-209-4702Depends on which ARP bolts you use, it’s either 80ft/lbs or 100ft/lbs for the 625’s
That's a disheartening picture.
Now that I have a spare head, I've been thinking of slowly putting a similar package together. Thanks for the updates.
Ha! I had high hopes with for MLX. A bunch of back and forth with Cometic, multiple 100mi trips, detailed photos requested. I'll be honest, it was kind of a drag. They really did their best in trying to not warranty the HG. At one point they had told me to drill out the rivets on the HG and re-align all 4 layers. I told them I wasn't planning on paying 250.00 to DIY my own HG, lol. In the end, the pictures and mic'd dims of the stock OEM gasket going on evenly is what changed their minds. Didn't want to take the gamble again so I went with a tried and true MLS, and another 5 weeks of waitingWell that head gasket is ruined.
Another small piece of the puzzle. If this one works it is going to be my best idea yet! Lol
So the 80 uses a shim on bucket design. Where under the cam you have a bucket that sits on top of the valve and spring and then you adjust lash by adding a thin shim to the top of that bucket.
Something similar to this.
In situations where you have increased the spring pressure, or increased the lift, or increased the lift speed of the cam, or increased the RPM's, you have the potential of that shim being pushed off the bucket because of spring bounce and banging around inside the head causing all kinds of problems.
One way to get around this is to do a shim under bucket design where you place the shim inside the bucket and it spaces the bucket up to the cam. The only problem with this is if the bucket wasn't designed to wear against the cam you get accelerated wear, metal flake, or if the bucket has lips to retain the shim they catch the cam.
This had been figured out 9+ years ago on the Supra's using later MR2 buckets. In the Supra it also reduces a lot of weight from the valve train. But obviously the MR2 buckets are way too small for the 1FZ.
So the Nissan series of engines including the GT-R, use a shimless bucket for the cam to ride on and compress the spring and move the valve. They accomplish this by offering many different sizes of "lifter-valves" these have the "shim" built into the underside of the bucket.
I know I am probably going to have to mill the underside to get it to match the valve lash perfectly, but you get a shimless system, a hardened bucket that even has a DLC (Diamomd Like Coating) on the face to reduce friction and eleminate wear!!
I won't know for certain if they will work until the Ferrea stuff gets here but that is supposed to be Monday.
Until then check these bad boys out! Lol
Well it is a success. If anyone else wants to try something like this while I go away for 18 months, it works and fits perfectly! The only piece missing now from a badass head is the Kelford cams and then putting it all together. The cams I was told are 60 days out and unfortunately I won't get to work on it when they show up. But if you are wondering.
Intake
Exhaust
Oh wow nice, didn't know you already explored this route. Did you ever test it out? We ended up going with Manley valves as Ferrea was more than I wanted to spend for a refresh.Yeah I bought those same cam buckets years ago, the only issue I can identify is that if you grind the inner pad to get the correct clearance you are removing the hardened layer of material and it will wear quickly. You can see if you can order the correct size but from my initial measurements it didn't look like it would fit. I would take a look at the Supertech system, where they use a cap shim on the valve stem.
No update from my side. I moved and shipped the head and cams across the country and didn't bother to open the boxes. When I finally did open them, both the head and the cams were broken and it was too late to claim them as damaged in shipping so I ended up loosing out big. I bought a new head and ported and polished it, but then I moved again. I have not replaced the cams or assembled the head.How did it work out with the Kelford cams Scott? Which valves did you end up using? Were you happy with the results! Very nice.
Man, that sucks.No update from my side. I moved and shipped the head and cams across the country and didn't bother to open the boxes. When I finally did open them, both the head and the cams were broken and it was too late to claim them as damaged in shipping so I ended up loosing out big. I bought a new head and ported and polished it, but then I moved again. I have not replaced the cams or assembled the head.