Twin cam head for the L6 from Derek at Datsunworks

[fuzzy]

Why come on down to your local Datsunworks dealer where December savings are in full swing. Bring a bag of cash and you can lug home a big ol chunk of cast aluminum:)

 

I will be selling them but we are aways away from that point. PM me if you are interested.

 

 

Got the throttle linkage and cable sorted out. I'm hoping the stuff I got with my econo kit from EFI Hardware works out well. Single cable pulley for 6 venturis may be asking a lot. The cable pulley is progressive so it may be fine.

 

And I definitely want to! I've got the bag part sorted out, now its just the cash 

 

I wonder it that counts as halfway there.

 

And why throttle linkage? Besides how much better they look. They tend to jam and stick more often, don't they?

[Derek]

And I definitely want to! I've got the bag part sorted out, now its just the cash 

 

I wonder it that counts as halfway there.

 

And why throttle linkage? Besides how much better they look. They tend to jam and stick more often, don't they?

 

 

As opposed to?

The only other method other than cable that I'm familiar with would be drop link. That would be my preferred method but budgetary constraints right now dictate that I give what I got a roll.

[texis30O]

I forgot to give you your sticker the other day.....

[Derek]

I forgot to give you your sticker the other day.....20151130_1436591.jpg

 

Nice. But now I've really earned it:)

 

Behold my hardline prowess!!

 

 

3/4" stainless .065 wall. Used my Hossfeld bender with a 1 7/8" radius tube die. All those years of building complex pipe rail finally paid off:)

 

Clears the dip stick nicely.

 

 

 

 

 

Another angle because...Why not.

 

 

Unfortunately I have to cut it as I created a line trap in that I can't remove the line without removing the pan or the head. I figured that was going to be the case but I kept it one piece as it makes for a better overall fit. I'm going to cut it up under the manifold on the horizontal section and clamp a piece of high temp hose between them. 

 

No biggie.

Edited July 7, 2017 by Derek

[Bob_H]

The 1/4" lines are feed. Look back at the most recent pics and you'll see a brass fitting in the back of the head. This is the main oil return. I have a 3/4" tube swageloc fitting on the way. I'm going to hard line it down to a bung I welded in the pan. I have a smaller hole at the front that will spill oil into the timing chain area.

.....

 

Ok, I see what you are doing now.  Next question it raises - once you determine how much is enough or "good" for a orafice size, do you plan to utilze the oil feed from the block through the head like a stock L6 or will it always be a dry mating at the head/block as far as oil is concerned?

[Derek]

Ok, I see what you are doing now.  Next question it raises - once you determine how much is enough or "good" for a orafice size, do you plan to utilze the oil feed from the block through the head like a stock L6 or will it always be a dry mating at the head/block as far as oil is concerned?

 

Hi Bob

 

The oil feed hole on the side of the block sits right under a cam tower so the feed will always come from elsewhere. I think it is going to work out well as the orifices are accessible from outside the head so tweaking the oil flow will be pretty straight forward.

 

I'm running a Melling M111 with no turbo so there is more oil available for me to disperse as I see fit. It will be interesting to see the pressure gain after I install the cams and rockers and the top end isn't free flowing. I don't know what size orifice is in the factory turbo but all things being equal the turbo oil pump should deliver the total of the 2MM orifice in the block and whatever size the turbo is. I don't have that data yet.   I don't know if this is the best way to go about it but it made the most sense to me. I've diverted from the normal K20 oil system so I need to pay close attention to my oil flow up top. 

[G-E]

For your captive pipe problem, could you not install a compression fitting that can be undone easily? or use a cup-and-o-ring setup like many oem injectors, since you know they'd have a hard time coming apart on their own?

[Derek]

That's a good idea but honestly the $20.00 items are tearing through my budget really quickly. And there is still a long way to go.

[ktm]

That's a good idea but honestly the $20.00 items are tearing through my budget really quickly. And there is still a long way to go.

 

....even for a regular build there are a shit load of those $20+ items that kills a budget.  Hell, a Goodridge -6AN 180 degree fitting is around $45 alone.

 

Amazing attention to detail and work.  I love how some in the community have rallied around this build and are offering their support and services.

 

I can't wait (I am sure less so than you, Derek) for first start!

[Arif]

Ok I'm late to the party but after catching up reading this thread I must say that this is the most important thread in the history of hybridz.org. I might need to buy a second s30 just to drop this motor in! 

Edited December 7, 2015 by Arif

[fuzzy]

As opposed to?

The only other method other than cable that I'm familiar with would be drop link. That would be my preferred method but budgetary constraints right now dictate that I give what I got a roll.

 

My bad - I didn't see the cable parts. I thought you were going with the stock linkage design. That normally jams up on me due to the many links.

[Derek]

Well the head was on and ALMOST torqued. Making the last pass and one of the studs popped. Unfortunately it pulled the threads out of the block. I guess I'll be ordering a time-sert kit. Not sure if I was over torquing or if the block was just tired. According to the ARP docs the head stud kit I'm using requires 85 lbs with their molly grease in order to get the correct stretch. The studs are quite a bit shorter than ARP l28 studs so that may account for the difference between the 60 lbs that ARP recommends for the L28 kit. 

 

Not sure how to approach this as I want the proper stretch but I really don't want to keep pulling threads out.  

[98blackbell]

Bummer on the stud. Good luck, all looks good.

[JavelinZ]

Well the head was on and ALMOST torqued. Making the last pass and one of the studs popped. Unfortunately it pulled the threads out of the block. I guess I'll be ordering a time-sert kit. Not sure if I was over torquing or if the block was just tired. According to the ARP docs the head stud kit I'm using requires 85 lbs with their molly grease in order to get the correct stretch. The studs are quite a bit shorter than ARP l28 studs so that may account for the difference between the 60 lbs that ARP recommends for the L28 kit. 

 

Not sure how to approach this as I want the proper stretch but I really don't want to keep pulling threads out.  

 

 

Derek, that sounds backwards to me. Solid Mechanics was a couple of years ago for me, and I am aware there are other factors that can go into figuring the proper stretch for a bolted application(especially in something subjected to heat cycles like an engine). If you have two bolts that are the same in every way except, they have different lengths. The longer bolt will have to stretch/ elongate more than the shorter bolt to achieve the same internal stress as the shorter bolt at a given stress. The total end stretch of a shorter bolt should be less than the longer bolt when it snaps. I guess what I am thinking is, if the stock block and head were fine at 60lb-ft why wouldn't this new head be okay? Torquing the shorter bolt to a higher value seems off to me.

 

Did ARP recommend that torque value or is that just what the kit said?

 

Also, even though the cylinder head thickness has changed (thinner) why would the factory 60lb-ft not be adequate for holding this new head? The iron heads on my AMC with 1/2" head bolts get torqued somewhere between 85-100lb-ft as I recall. That sounds a bit much for an M10?

It is pretty common practice in the AMC community to machine early blocks with 7/16" head bolts for 1/2" when updating to later dog leg heads that used 1/2" bolts. Maybe larger M12 head studs would be a good idea if this head needs more clamping force. Granted there are high horsepower L motors out there already and I haven't heard of people tapping their blocks for M12 studs for more clamping load to get there. I'll stop here, just thought I would spill my thoughts out for your consideration. Maybe someone else with more experience than I, can offer some input.

Edited December 7, 2015 by JavelinZ

[Derek]

Derek, that sounds backwards to me. Solid Mechanics was a couple of years ago for me, and I am aware there are other factors that can go into figuring the proper stretch for a bolted application(especially in something subjected to heat cycles like an engine). If you have two bolts that are the same in every way except, they have different lengths. The longer bolt will have to stretch/ elongate more than the shorter bolt to achieve the same internal stress as the shorter bolt at a given stress. The total end stretch of a shorter bolt should be less than the longer bolt when it snaps. I guess what I am thinking is, if the stock block and head were fine at 60lb-ft why wouldn't this new head be okay? Torquing the shorter bolt to a higher value seems off to me.

 

Did ARP recommend that torque value or is that just what the kit said?

 

Also, even though the cylinder head thickness has changed (thinner) why would the factory 60lb-ft not be adequate for holding this new head? The iron heads on my AMC with 1/2" head bolts get torqued somewhere between 85-100lb-ft as I recall. That sounds a bit much for an M10?

It is pretty common practice in the AMC community to machine early blocks with 7/16" head bolts for 1/2" when updating to later dog leg heads that used 1/2" bolts. Maybe larger M12 head studs would be a good idea if this head needs more clamping force. Granted there are high horsepower L motors out there already and I haven't heard of people tapping their blocks for M12 studs for more clamping load to get there. I'll stop here, just thought I would spill my thoughts out for your consideration. Maybe someone else with more experience than I, can offer some input.

 

Interesting points.

 

The ARP kit says 85 lbs as well as their pdf on the website.

 

The studs are from a BMW M50. I believe that block is aluminum. They do have issues though as there are timesert kits specifically to repair them.

 

I'd like to hear from someone who has run those kinds of torque on a L28 block. None of the other studs felt even the least bit mushy so it may be a case of a single weak thread.

 

Thanks

Derek

[TimZ]

Interesting points.

 

The ARP kit says 85 lbs as well as their pdf on the website.

 

The studs are from a BMW M50. I believe that block is aluminum. They do have issues though as there are timesert kits specifically to repair them.

 

I'd like to hear from someone who has run those kinds of torque on a L28 block. None of the other studs felt even the least bit mushy so it may be a case of a single weak thread.

 

Thanks

Derek

That does sound really high for an ARP 10mm stud, especially with their assembly lube.  When I bought my l-series-spec'ed studs several years ago they specified what seemed like really low torque specs - something like 45lb-ft with assembly lube and 55lb-ft with motor oil.  They have since upped that spec, but I didn't think it was that high.  

Personally, although I do like their products, I think ARP has done a lousy job of spec'ing these.  There are multiple specs floating around to the point that I'm not convinced that anybody really knows what the right number is.  I do recall a friend of mine snapping one of these after being told that the "real" torque spec was 90lb-ft.  I don't recall whether this was with assembly lube or not.  I generally torque mine to 65lb-ft with motor oil.

Edited December 8, 2015 by TimZ

[righteousrags88]

Literally just spent the last 4+ hours reading this entire thread from page one. Didn't know what 99% of what all the science and numbers meant but who cares! Cant wait for when these heads are ready for purchase although I may not have the cash when they do but I sure know how to make things work.  Glad I got into the 240z scene a year ago. Keep it Up!

[clarkspeed]

Look up the stud kit number on ARP website. It links to their correct torque spec.

Not unusual for older block to have some corrosion in the threads if water ever set in there.

[Derek]

Look up the stud kit number on ARP website. It links to their correct torque spec.

Not unusual for older block to have some corrosion in the threads if water ever set in there.

 

 

There was some corrosion in the hole.

 

85 lbs is the spec. on the kit. 70 lbs is the spec. for a 10mm 220,000 psi stud in their general torque value chart.

 

I'm leaning towards 65 lbs and calling it a day. It's a low compression NA motor.

[bradyzq]

I don't know if this is applicable to you, but beware of crushing the head slightly due to using the too small washers ARP supplies with some of their head stud kits. This is known to happen on some older Audi heads, where you can end up with a washer sized dimple around each stud.