More cool shit... my new head studs arrived today. These are very custom ARP CA 625 plus. Around 27% stronger than 2000 series and fully corrosion and oxidisation resistant and good fatigue resistance. No you can’t find these in the ARP catalogue. Yes can order in but will cost you over $1k/set. I’ll be using these in the heads and L19 in the mains.
Should be able to give it more preload... I just had a look at ARP website and they only list specs for 220KSI fasteners. These are a 260-280KSI fastener so I might have to send them an email...
Those look lovely! I just used some normal ARP head studs on my Twincam rebuild and was impressed with the finish. Those are nearly too nice to hide in the engine
No real updates on my motor but I had a chance to compare the weight of cam assemblies as I’m packing up some parts for customers. For starters the VTC intake sprocket assembly including the cover plates, o rings, and the cover plate screw is quite hefty at 1848g. These cams are a VTC version of the intake cams I now have in my motor. It looks like I didn’t weigh the cams when I had them in hand but the VTC version comes in at 1714g. I would expect mine to be heavier as they don’t have oil channels etc. And here’s where the money is. The whole VTC assembly including cam, sprocket, bolts, VTC springs, cover plates, screws and o rings comes in at 3652g. So I’ve cut down 1135g of rotating mass off the cam assembly -yes this is at the expense of VTC but hopeful that this will help with my overall goal to gain some more rpm to play with. Lastly a couple of pics of where JUN hand engrave the specs on their cams. I remember this coming up a little while back when someone was trying to determine if some second hand cams were in fact JUN items -now you know how to check. These ones are going to a customer in Canada.
Got my hands on a JUN exhaust cam (partner set of the intakes above) to weigh today. 292g heavier than an intake. Just in case anyone is still interested lol For argument’s sake I also weighed a JUN solid intake gear and bolt. Substantially lighter than the OEM intake gear but intake cam/solid sprocket combo is still about 480g heavier than exhaust cam/BDE sprocket combo. Interesting stuff for people who dig data.
More new bits to collect dust. A few of you will know I’ve been involved with a group buy to get these Ash plenums to AUS. Nearly two years after dumping a significant amount of money into the venture we’re starting to see them arrive including this one I have set aside. Another piece in the “keep it spinning at high rpm” puzzle. A few other members have these or have them on the way (about ten I think) but I’ll leave that to them to share or not share. I have ended up with a few spares but price tag starts at $2k... feel free to PM if interested in one.
Shorter runners are tuned for high RPM. In theory; the stock manifold is tuned for peak airflow at about 4500rpm (which is where the stock turbos peak). Keeping in mind that air flow through the plenum is dynamic and affected by the speed at which the valve at the other end of the runner is opening and closing. Most of the mods we do such as upgrading turbos, cams, other bits and pieces move peak volumetric efficiency into the higher rev range. The plenum will be better suited to high RPM. The chart below shows some testing that Ash did. Yes a lot of it involves taking his word for it but the theory is sound and a fairly common place upgrade on other platforms so I'm confident.
Seeing some engine progress which is really nice. Has been a long time coming but things are happening and from what I can see and recent contact with the builder I’m sure that the job is being done well. Will share my thoughts on that more fully when the motor is received. Facebook guys might have seen these pics already. Torque plate honing Billet crank shaft CP pistons 89mm and 10:1 compression with Carrillo rods and 3/8” CARR rod bolts. Have also gone the upgraded CP wrist pins. Bottom end coming together with billet main caps, ARP L19 studs, and the billet crank. The last couple pics really show the high comp pistons off. Running dual knock sensors again; at the moment I have a Link Thunder set aside for it that can run dual sensors with knock windowing etc so I want to give it the biggest set of ears that I can especially with high compression. Don’t want to set myself any deadlines but with any sort of luck I’ll be back in the car early next year.
And some top end pics. Heads are series 2 10Y non turbo heads. Relieved for big camshafts. Cams installed. These are 10.5mm lift and .272 duration with sold lifters that I had custom made by JUN. Will really open up the top end -yes it’s going to be another lag monster but high comp, e85, modern turbos blah blah blah factor into it too. Some of the port work with bronze valve guides and super tech 1mm O/S valves. I had to have the calves custom made as super tech only so .5mm off the shelf, but I wanted inconel (like factory) on the exhaust side so.... Lastly the combustion chambers have also been coated.
Wow- I knew you were getting some interesting bits and pieces. I like everything apart from the L19’s. The question that everyone will want to know now is with such large cams and the manifold suggesting improved flow up top? What “lag monsters” are you going for? Are you also doing a solid lifter set up to rev past 7500 with a little more comfort?
What have you heard about the L19? There’s a lot of misinformation and conjecture floating around the internet. A lot.
The usual that apparently they can corrode and don’t like the moisture that ethanol/similar fuels can produce. I noticed the custom head studs- there was a interesting write up by EP regarding the torque of head studs and how the larger studs or being over torqued doesn’t necessarily mean the heads will be more secure? What was your take on that or are yours within factory torque specs for the head material? P.S. I noticed you avoided the “lag generator” question hehe
Thats right -not using them in the heads for this reason just the bottom end where they will see plenty of oil. Not larger studs but stronger material. It’s a bit of a case of he said she said, will post more on that once motor received. I’m not sure what exactly you’re asking?
Thanks Geoff -made plenty of silly decisions along the way so I’m trying to make some sensible ones as well haha
