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zredbaron

NA 3.1L=>head & camshaft questions. No shortcuts, max

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Guest billyzbear

And I would get an ITG air filter and get those fuel lines away from the header, keep them cool.

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Guest billyzbear

Soory one more thing crome valve covers retain heat. I read it in a Hot Rod Mag that did a very good article on it. I didn't believe it either until I read it. An upper stress bar will do wonders. I like the brakes.

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Guest billyzbear

Ok this will be the last time, where is the hose going that is coming off the valve cover?

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billyzbear,

 

The hose is going into my intake manifold, #2 cyl. I used to have a breather, but it made a mess out of my engine bay. A mechanic told me that I should let my engine suck it out for me. I never really liked the idea that much, mixing that mess into my gas/fuel, but I blindly trusted him. Thoughts?

 

I've got a 3 point strut brace. I had it chromed but it was flawed so they're doing it again. It will be on soon.

 

What's the problem with retaining a little heat in the valve cover? And by the way, I'm working on getting a TWM cold air intake. The K&N chrome is pretty, but cold air will help a lot, and I won't have to mess with blankets and such.

 

Thanks, the brakes really hold up. I fully recommend Ross and his MML kits. They are very sturdy parts, and he goes out of his way to set up up the way you need to be set up.

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Haven't really considered anything. To be honest I had forgotten about it.

 

What do you do? I think the exhaust option sounds the most appealing, how exactly do you pull that off? Drill a hole and put in a check valve, or what?

 

On another note, I'm shipping out my head to Sunbelt tomorrow. Whoever told me a while back that the 3.1L stroker kits have a .025" positive deck height was right on the money. I measured it: exactly .025".

 

Translation: I can put in a cam with ~.520-.525 lift (using a 2.0 mm gasket). I wasn't told the duration, but was told I would have power from 3200-7200. And yes, JohnC, Jim is using what he learned from your R&D, I will have single springs in the head. He expects a little over 200 cfm per cyl., and thinks my 40mm webers will be just fine if jetted and choked properly... :2thumbs:

 

And Jon, I just realized I forgot to ask about buying a cam individually! I'll get back to you, I promise! I know you mentioned before that you were unsure about swapping out a cam that might be .500, but heres the .525 we always wanted. I was really impressed talking to Jim. Plus, with less spring pressure thanks to their lobe shapes, thats even more power to the wheels!

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http://www.jegs.com/cgi-bin/ncommerce3/ProductDisplay?prrfnbr=1783&prmenbr=361

 

Just weld the fitting into the collector and connect to the valve cover. I guess you could connect via a tee to the vent on the side of the block as well, but if you look in the How to Modify book it warns about having too much vacuum. For this reason I was thinking I would put a breather on the side of the block (just a little K&N filter) so it would really just get rid of pressure and not create a huge vacuum. Or vice versa, maybe connect the hose to the side of the block and run the filter on the valve cover. I am going to do this as part of my latest round of modifications, if you want I'll buy this and I can send you 1/2 for $20. You really only need the nipple and the check valve, the other stuff fits V8 valve covers, and the L6 already has a built in baffle in the valve cover.

 

Jon

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Guest billyzbear

The port on the valve cover is the breather, put a K&N little filter on that one. The pcv port that would get vacuum is under the exhaust manifold up front. The cold air induction sounds great, I plan to do something like that for mine. What about the fuel in the carbs and fuel lines? What about the heat coming off of the header onto the intake manifold? I'm telling you I can feel the difference without the heat shield. Not sure why your fuel pump is on the driver's side. It should be on the other side. The fuel line out and return is on the passenger side. Put the pump there and route it over the engine and to the carbs. You really don't need a fuel return. The line on the driver's side is for the fuel evap. Originally on the driver's side there was a portioning valve that that line went to and the other end went to the pcv hose(vacuum).

On mine, I have two pumps. One that puts out 1 pound of fuel pressure and another that puts out 6. I run just the one pound when I'm being mellow. Leans the mix out some but not to much. I didn't plan this it just happened. The other is a 260z pre pump or the same one you find on a 85 truck. It has lasted over 12 years.

With a crome valve cover the oil runs a couple of hundred degree hotter. All so when you pop the hood people go wow look at that shine. Black is best. I think thats why the turbo valve cover is black but not sure.

What pistons did you get?

Do you have MSD or Crane? What are you useing for ignition?

I hope you don't get valve float at high rpm's with only the one spring.

Billy

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hahaha, easy john. by the way thats the second time you've cracked me up today. i read one of your older replies to the gas mileage thread....6 gallons per hour...i love it! even better was that no one seemed to notice, everyone was so proud of their 30mpg...

 

i assume that was a typo about the temperature, billybear. if it were a couple hundred degrees, there would be some serious problems. the water temp in the radiator isn't even a couple hundred degrees.

 

and by the way, the hoses topic is not what this thread is about. i will reply in case any silent readers are wondering or confused, but lets keep this post about performance head and camshaft stuff, shall we? feel free to email me if you have further comments or questions about that stuff or my setup.

 

i will be the first to admit that my hose setup needs revamping. thats not a fuel pump you see at the bottom, its a pressure regulator. my fuel pump is electric (nissan competition) and it mounts near the fuel tank. the two fuel lines you see are both sending fuel to the carbs, there is no return line. yes, im sure they are a bit warm there, and yes, I plan on moving them. i also think i'll take out the pressure regulator, i dont think i need it with the nissan comp pump. you may be right about the intake manifold getting warm, particularly sitting at stoplights and such, but at speed i would bet it is negligible (johnC, what does the racer's voice say?). the pistons i have came with the 3.1L overbore kit i got from nissan (more or less flat tops). my ignition is direct, no sloppy points--three coils and a controller. thats it. (which is why the distributor has been replaced with a blanking plate, and you see not spark plug wires, they are on the other side, and short) electromotive ignition allows me to plot an advance curve that changes with rpm (electromotive hpv-1). i am an electrical engineer and i stand by their design over msd, crane, etc anyday of the week (if anyone wants details why, email me). i literally experienced a 19% increase in power from this ignition (dynoed, have the printout to prove it). i attribute this to the advance curve that you can dial in, and the fact that my timing was mildly retarded on the initial run (to protect the engine since the e31 head brings high compression with the stroker kit).

 

as for the valve float at high rpms with only one set of springs...this is engineered by sunbelt, reputed to be the best in the business. they have a cam lobe design that doesnt require firm spring pressure in order to hold the rocker arm in contact with the cam lobe. just believe, buddy. they're that good.

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Guest billyzbear

Just believe, buddy.

 

That seems alittle harsh. Is that how you wanted to come off?

The article was like four years ago and my memory isn't what it once was. Maybe it's the beer. Anyways, I posted on thier website hopefully someone else will back me up. Yes, it was alot more than you'd think. Just how hot do you think your oil gets?

I've seen your ignition setup before. It's real nice to set your own timing curve and have multiple coils. I would have to agree it's better than MSD or Crane solutions.

Are you still planning on going really high with compression?

Have you picked out your flywheel yet. I had an HKS 10 pound flywheel before but it was too light. The car would rev up real fast but would not hold it between shifts. 15 pounds is about right. When I was working at Nissan I used thier comp clutch's and pressure plate but found the disc to wear out in 6 months. The comp stuff was at cost and regular stuff was 10% over cost. I switched to a different disc's but still kept the pressure plate. It was either in or out and was pretty stiff. I can't remember what the brand was but got it at Ed's Place in N. Hollywood. Now, I'm useing the turbo flywheel with stock disc and pressure plate from Nissan.

I hope some of my exp. helped.

Billy

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Just how hot do you think your oil gets?

 

Lay off the beer and go read your source again. Typical oil temps on a street car are around 150 to 175F. If your chrome valve cover is adding 200F you're looking at oil temps beyond the design limits of any oil that you or I can purchase. On a race track you start worrying if your oil temps exceed 240F for regular oil and 275F for synthetic oil.

 

you may be right about the intake manifold getting warm, particularly sitting at stoplights and such, but at speed i would bet it is negligible (johnC, what does the racer's voice say?

 

With no air flow through the engine compartment you will see high underhood temps (typically 100F over ambient) but once a car starts moving over 20mph underhood temps drop to something like 10F over ambient. I saw a test on a Ford Contour using multiple temp probes that confirmed the above. The 240Z, with its more open engine compartment, should see at elast a similar reduction.

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Red Baron,

The vent tube on top of the cam cover isn't meant to see manifold vacuum, just filtered ambient-pressure air. Stock goes to the air filter, if you don't mind drilling a hole you could run it to one of your filters. I'm just using the itty-bitty K&N. It's the tube in the side of the crank that wants to see vacuum. I'm currently running that to a PCV valve to a balance tube setup on top of the manifold runners. I might try something goofy like eliminating the intake runner balance setup and have a PCV valve for each runner to a vacuum canister, from there to the crankcase and brake booster.

 

I'm running a fuel return line. Sould help keep the fuel a lot cooler. I have no heat shield between the header and the carbs, never have any vapor lock issues.

 

Billyzbear,

I don't think Zredbaron was really trying to be harsh on ya.

John, on the other hand...

:lol:

 

Just kidding, it's one big love-fest here at hybridZ. Just don't take anything personally. I've got the Sunbelt setup as well, one spring per valve. I limit at 7200, but the valvetrain should be good for a lot more, at least 7500. You really run to 8500+?! I'm not that brave. I don't think my bottom end is good for any more than 7500, max, and I don't see myself going that high with a stock diesel crank and 240 rods.

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Thanks Dan, I'll have to reevaluate all my hoses next time I get a chance. I'm glad billzbear pointed it out, so thanks bud. And no, there were never any hard feelings.

 

I don't plan on running past 7500 either. Where did you get the 8500 rpm figure? I don't think my diesel crank setup would like that very much...

 

Is that about right for the other 3.1L guys? No one goes past 7000-7500, right?

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zredbaron,

 

I got the high rpm numbers from one of zbear's posts. I don't plan on running mine that high. 7500 would be my absolute limit, and only for a limited time, like at the drags, or for a 3-lap time trial run.

 

My old 2.8L put out 240hp, flat tops, N42, 3 40's, Crane Hi-6 and cam 495 lift and 280 duration. It has good power from 2000-6500 rpm. I had a 510 lift and 308 duration cam in it along time ago but wasn't much good for street and had problems with wear. Good power from 3200-8500 maybe even 9000. I use to set the rev limiter at 9000. Never got that one on the dyno.

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Guest billyzbear

As for the chrome valve cover, I can't come up with the article. I can't say +200 degrees maybe it was 200 total, it's been to long. I do think your oil will run hotter with it. Normally, I think your oil would run a little hotter than your water. Take it as a grain of salt.

I put on the 45mm Webers today. I went from a 30mm choke to a 38mm choke. I haven't got them dialed in just yet. Mid-range it falls on it's face some and wide open seems a little lean to. I'll keep you updated on if it's worth it. Does anybody know how much cfm flows through a 38mm choke?

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Yeah, ask him. Thanks. I'm betting it includes rocker arms at $500. Not a bad deal, but I've got other places to spend $500, since I already have a fairly similar cam now. It would be a small step up for me, but a huge one going from a stock cam.

 

Okay, Jon. I spoke to sunbelt today. Their quote, not a final price, is $450 for the cam, and the price includes a set of the single springs. The quote is good for any grind that they have engineered before, if anyone wants a unique, never before attempted grind, the R&D brings the price up to $1500.

 

If you do end up calling, mention that Jim knows what cam he's putting into my E31 head, and that you want the same one, as it clears the 3.1L kit if you use a 2.0mm gasket. Again, the lift was in the neighborhood of .525" (maybe it was .535"? i dont remember for sure), and duration was such that the power band was 3200-7200 RPM. Their number is (770) 932-0160.

 

Good luck!

 

-Mark

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No problem, Jon. Also, those numbers will be solid sometime next week. He's got my head, and will run numbers and such soon.

 

I will formally have the cam specs next week sometime, I'll post em when Jim gets back to me.

 

Also, I opted to get exactly what JohnC had done to his head (ouch -- $$$$), except in an E31. Again, assuming the .534" lift will clear. Is your power from the 3200 - 7200 band too, John? 3500-7500? Higher?

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Haha! How did I know I was going to get an answer like that, John? For some reason I thought you were carburated, but silly me, I should have known that I have no clue what the hell you have done with that ridiculous car of yours...

 

Any reason you went with the Motec EMS over the TEC-3? Also, 65mm...thats way too big for 3x2 TB, right? So how exactly are you set up? Do you have a picture of this engine of yours?

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Sunbelt head installed....finally!

 

According to their printout:

 

stock (head before any work) port flow:

.......................intake.................exhaust

.425" lift...........158.9 cfm...........110.2 cfm

.525" lift...........163.5 cfm...........118.4 cfm

(.525" lift never reached with the cam i had in it)

 

final port flow:

.......................intake.................exhaust

.425" lift...........180.6 cfm...........129.3 cfm

.525" lift...........201.6 cfm...........145.1 cfm

 

according to sunbelt, 200cfm by their flowbench (flow pro) is 225cfm by anybody else's (super flow).

 

The cam Jim set me up with has a lift of .520, and powers from 3500 - 7200. Cam lobe duration is 290° for intake, and 274.8° for exhaust (yeah, that seems ridiculously precise to me, too).

 

It should also be noted that Jim said the L6 motor doesn't start making any 'real' power until your lift exceeds .550". Damn.

 

My old head produced 157 rwhp, and this one produces 197. Quite a dissappointment considering my investment. On a positive note, it pulls hard to around 7250 rpms and sounds absolutely beautiful.

 

DynoPSep2004.jpg

 

DynoFSep2004.jpg

 

Any thoughts on why my rwhp is 50 hp < similarly built engines? Valve lift and carb tuning are issues....but 50hp?

 

Not sure what's going on under 3500 rpms...I've been meaning to call sunbelt but haven't got a hold of them yet. Jetting? Cam lobe?

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Got any lambda or other mixture ratio data? Without that you could be losing tons of hp in tuning.

 

Second, chassis dyno numbers don't mean squat unless it's relatively back to back pulls. Way too many variables.

 

Do a leakdown check just to make sure the bottom is sound. Eliminate the obvious and easy things first.

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