A PM regarding 3.5's HG's and timing
 

That I thought had some good info in it that was worth posting in here.

Also, since I'm real busy with life outside the .org, preparing for the move into the new garage, among other things, I'm just going to copy & paste and keep this all messy, the beggining is info from a previous phone convo.




If you're doing a 3.5 hybrid swap, having the inner and outer timing covers off, as well as the engine out of the car, sort of makes you a knucklehead if you don't decide to get rid of the 2-layer headgaskets right than and there. Ask me how I know this....... Because I'm a knucklehead, durr. Mild white smoke only on occasions (when it "felt like it", lol) As well as combustion gasses in the coolant, and a mysterious tendency for my car to ever so slightly push coolant out of the expansion tank during hard driving.

The other thing to note is that there is a slightly misleading, almost a typo, in the '02+ fsm's. Unlike in the FSM's for the 3.0's, during the removal steps for the cylinder heads in the 3.5 fsm's it makes it seem like the picture of the removal tourqe sequence pattern is exactly that, but it's not. It's just the regular tourqe sequence for installation, you need to reverse it yourself, but the way they word it implies otherwise, especially if you've done it previously on a 3.0. This actually applies for every sequence in the removal sections (like main's). Take my word for it, or if in doubt just use a 3.0 FSM, all of the key removal tourqe patterns are the same.

Anyways......

Didn't get to finish, but anyways, I've perfected the art of absolutely 110% zero possibility of jumping timing, and one of the most important parts is....

USE A BRAND NEW TENSIONER!!

Get the whole kit (guide), submerge the new tensioner in oil, push it in and out a bunch of times, while still submerged insert the holding clip again ( I actually prefer to not even use it, allows me that much less air, but it's negligablt amounts). Line up the chains,blah blah blah, get the slack on the tensioner side, blah blah blah (blah = consult the fsm). But THAN, after you pull that pin... try to avoid at all cost's moving the tensioner back in again. Once it is installed, everything tightened etc, double triple quadruple check all the marks/links are lined up, and than rotate the crank 1 revolution while watching to make sure it doesn't skip. No need to do it more than that.

Basically, you might have to re-do the whole submerged pumping step until you get the hang of it (lining up the chains & installing tensioner without having to push it back in at all, or even better- back in all the way to the clip point)

Just trust me on this, print this off for when the time comes, & you won't jump timing, you might have to start from the beginning a few times until you get the hang of it as opposed to just slapping it on per the fsm, but it's worth the extra time. AND DO THOSE HEADGASKETS! Reverse tourqe in several steps for removal, 3m scuff pad or 400 or higher grit sandpaper + brake-cleaner to wetsand/clean both surfaces spotless without going overboard. (I actually use a large expensive peice of 1/2" plate glass + valve lapping compound for the heads).

For all this stuff, compressor w/blow-gun is almost mandatory, and for the headgaskets cutting the correct size allen and than using it inside the socket for a 1/2" drive, I've actually permenantly welded one togethor just for this, I'm sure someone sells one, but you can make one just as easy. UPDATE: This was done because, as others have also found out, 1/2" drive 10mm allen sockets are NOT readily available in stores. If you would like to save a couple dollars, you can order one HERE as well as other places online, or from a snap-on etc truck. However, allthough it *might* be OK to use a 3/8" 10mm allen socket (which are readily available) with a 3/8" to 1/2" IMPACT GRADE adaptor at the least, I personally wouldn't recommend this just because if that thing lets go 1/2 way through an angular tightening step, it has the potential to be bad news (thank god for the 3-step program listed below ;) ). Make sure you use the "correct" tool for the job, whether you have to plan ahead for this or make your own, do what you gotta do.

Also, many people out there will say that you MUST use a tourqe angle meter, and I wouldn't challange them on that, BUT I would NEVER recommend relying solely on a tourqe angle meter, they can be a little tricky to set-up on the VQ heads and if they slip you are screwed, I also make little scratch marks on the bolt heads & the cylinder heads by eye but very carefully and anally, you will end up with a perfect cross. I also do it visually with the actual [ratchet] & engine during tightening. (lining up the ratchet & breaker-bar parallel to the engine, hard to explain but will make sense when you get to it). When I've done those 2 things & used a tourqe angle meter- the meter confirmed that I was spot on, and well within the +/- 5* or whatever the FSM says.

Also, on another note about tourqe angle meters, since you will definitly want to use one on your first build, do not even consider a cheapo "oem" brand one from autozone, Snap-on etc is a MUST, the cheap ones will all of a sudden randomly decide to slip on the inside plate of the meter/needle assembly and you will be tempted to hang yourself right than and there.

Oh, and you will want to be standing on the engine stand for all of this, even if you have somebody else to hold the engine, it's just more fun that way.

And for those that need it, here's the link regarding what HG's and bolts you want to use......

http://www.jimwolftechnology.com/wol...D_GASKETS_HEAD

^^^Yes the HR head gasket and head bolts. I posted about this a few months back, don't remember which thread now. It's a better option than regular DE HG/bolts but if you're going to use the HR gasket there is some machining on the block that should be done.

the link doesn't work

Try that:

http://www.jimwolftechnology.com/wol...HEAD_BOLTS.pdf

you know i just pmed you about something related to this whole thing before seeing this thread

Damn good info as always kev.

thanks for the link too, the bolt comp. was a good reference since I will need longer/stronger bolts for my heads with that ~8mm I am adding to the block

I don't see the "typo" in the FSM's. They recommend loosening from the outside in and tightening from the inside out like it should be. :gotme:


As for sandpaper and lapping compound on the head gasket mating surface, I'd be curious as to whether or not the required Ra smoothness has been compromised.

But +1 on the HR hardware, even if Dan beat ya to it... :hide:

^^ I chuckled... :chuckle: :hide:

Interesting.

I installed new HG's on my 2nd 3.5 swap. Torque sequence was acurate and 7k and no problem what so ever. I cleaned the block up, but did not sand it down etc. Again 7k and running strong, with no problems what so ever. I am not emphasizing that to say one should not do it.

I agree new tensioner and guides should be used. I used new ones each time. I did not submerge it in oil the first time, and the 2nd time I put a little oil in. Both motors are running spectacular.

I agree with phmor. I bought a 10mm hex socket 1/2" versus rigging one up. Much easier and faster.

Great post and good info for others and future swappers

Good link, appreciate you posting that, but no need to be a jerk about it, notice how Mdeezy put it?

I mentioned that because I needed to get a set of heads off and after a 3 hour adventure driving to both the taunton and kingston sears, as well as checking at two local auto-parts stores (One of which has an excellent selection of tools) I was not able to find one. I didn't have the liberty of ordering one online, and could easily see others in the same situation so I posted that so they could be prepared ahead of time. If you follow your own link you can see it clearly says "online only"

I was never able to find a 10mm hex bolt in local stores, at least not in 1/2" (needed to use it on a break bar/impact), I ended up ordering it online from amazon. Sometimes you may get lucky with a store having it in stock. There are those times when you dont have time to order online, and need something that day... thats when we Macgyver something up (as I like to call it)

I bought a 3/8th but it slips when trying to get the head bolts out. 10mm fits snug and doesn't slip between the hexes. Also I broke my 3/8-1/2" adapter when using it on a break bar.

I use a 1/2 to 3/8 adapter to remove/install head bolts with no issues. Then again it's impact grade.. :o

Nismology, you are correct, I'll take that out, the Typo is NOT in the FWD FSM's, I thought it was and should have double checked it, thought I remembered it being there, but it is in the '06 Z fsm, and the '03 Z one also makes the similiar mistake but not as bad.

Werd, and long time no see :) Glad to see you around a bit more. Anyways, I'm not recommend sanding it down by any means, just very carefully cleaning it up very very well, as well as leaving a good finish on it. If you look closely; especially on higher mileage motors; the black coating really pounds itself onto the surfaces, any sort of method involving cleaner and rags is useless, but you have to be very careful because 1: It's easy to remove a few thousandths from aluminum. And 2: The finish has to be right.

As Nismology mentioned, in some apparantly way secret part of the FSM it gives a specification on this, In the form of Roughness Average, or Ra#, though I just looked around pretty good and can't find it right now. But whatever, if you follow any of the methods I listed above it will be good, just take my word on it, my streetbike ran great with NO headgasket :D The valve lapping compund leaves the superior finish out of all of them.

In regards to copper spray, since it may get mentioned at some point, I prefer not to use it on the VQ HG's, since they come with a tacky coating on them, but I have used it on mls gaskets in the past and "not had a problem" would be an understatement, allthough there are some on here that have much more engine building experience than me, and still others with less experience but more "knowledge", I built a cobra motor that has been pushing 18psi for the past few weeks on a crappy tune, and after the new axles go in I'm expecting it to put down >600. All it has is a cheap basic felpro-gasket, the surface on the heads was done by a machine-shop, valve-lapping compound was used on the block, and the gaskets were sprayed.

thanks for the info, btw Kev are you going to the nyc meet on the 19th cause I may take you up on your offer

but either way I let you know how things work out

FWIW, I used a Sears 10mm-3/8" driver to take apart four 3.0 engines and pulled the heads off my first 3.5 and re-assembled it using 350Z gaskets and new head bolts. No later problems with the 3.5 - not even under a combined 100-shot of nitrous. Wheee...

I used a 2-ft breaker bar and a 3/8-1/2 impact adapter, and snapped one 10mm allen-head socket early on. Sears replaced it no-charge and I also bought a spare, but nothing else has broken since.

I did clean the heads and block with acetone and a wire brush mounted in a slow drill. THe surfaces came out very clean and smooth, with no scratches, and the acetone cleaned off everything stuck to the block and heads. Since that worked well, I also cleaned off the tops of all the pistons and into the combustion chambers. Then the oil pan, block and timing covers got the same treatment and made for a much nicer cleanup than scraping everything with a putty knife. Lots of RTV later, no oil leaks. :D


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fascinating.

4 thousands was taken off and the block finally was cleaned up. That is (seems to me) a very thin layer, but it also seems to reveal how little is needed to be taken off to clean up.

So sanding, and devices cause an un even layer, but with the HG put on an torques in sequence, how is those variations still that significant after the HG is bolted down.

Or better yet, there is a copper spray that can be used to aid with better sealing, how could that in combination with the new HG not over shadow those variations.

Ideally it would be better to drop off your block at a shop to be measure a cleaned as seen in the video, but if that were to cost say $200, and an enthusiast could achieve close to the same results if not the same for a large fraction of the cost, but for the same results/performance, then one will tend to lean towards the more cost-effective side.

edit: my $ amount figures are just ball park guesses

The point of that video was "Don't take power tools to the HG mating surface", if you didn't catch it the first time. :)


In other words, what he had to do won't be necessary unless you do ^.

Definitly fascinating, nice link homo. Was watching his other videos and saw this one, http://www.youtube.com/watch?v=HlCrkytRwls found it very interesting that they could straighten heads, I remembering seeing my good machinest had a similiar set-up that was an oven and it rotated except at the time he was using it to pressure test a deisel deisel cylinder head, it was like 5 ft' long, I wish I could remember what it weighed. Back OT, .004" isn't much, and the fsm just states a RA and a flatness (which is same amount IIRC), not sure where the overlap between those two specs would collide (does this make sense), however .008" is also the the limit that can be taken off of the head & block combined.

As for spray, I've used it on every single engine or HG I've ever touched..... Until I layed my hands on my first factory nissan one for a VQ. I opted against it at the time because the amount of tacky stuff they already put on it.

Again, the point wasn't how little it takes to repair a damaged block. :squint: The point was, mounting something on a grinder or rotary tool and cleaning the block with it can cause real damage and unless you take it to a machine shop and have it repaired, you can run into problems.


And Ra and the "flatness" spec are two VERY different things indeed. The FSM doesn't mention the former, to my knowledge. There's just a universal target value whenever MLS head gaskets are used on all-aluminum engines.