Blown head gasket :(

[BlackBirdVQ]

side shot of the VTC sprocket, and front of the head. I was able to remove the head with camshafts installed, if you keep the cams aligned correctly they have notches in them for removal of the head bolts. I will be having my machine shop mill the heads if needed with camshafts installed for optimum straightness.

[BlackBirdVQ]

pic of the engine with both heads lifted off the block. I need to check the block deck for straightness and see if I need to mill it. Only thing you need to be worried off when doing machining on the head and block is not to take off too much material or the hydraulic timing chain tensioners might NOT be able to compensate for extra timing chain slack.

[BlackBirdVQ]

So there ya have it, its POSSIBLE to do this job in the car- even thou the FSM says to pull the engine out to do this. I found that with my rusted azz exhaust system I wasn't going to have much fun with removing of the engine. Plus I didn't want to spend all that time with removing it if I can do the job faster in the car I think. I will post pics of my cylinder heads after they return from the machine shop, which will be bout 2 weeks from now ( I got Acura new model traning and advanced emission diagnostics all next week at our Honda/Acura training center) and I hope to have everything buttoned up within 1 month.

I am having the intake manifold polished- possibly doing the lower intake runners also (aka lower intake manifold), doing the timing chain covers polished, misc brackets powdercoated in candy apple red to match the valve covers in red. All plastic engine covers will be carbon fiber.

Then its off for my custom exhaust system, putting my Cal Custom springs on with Tokicos, and buncha SPL goodies. I got some HP Racing EVOs in 18x8.5 with tires to go on it and I should be set for a lil bit.

[Q45denver]

You might consider some new rod and crank bearings. I'm on my fourth engine in my Q45 and each had bad rod bearings.

[BlackBirdVQ]

I really don't wanna pull the pan down to do those :P I done a few rod bearings in my SR20DEs and SR20DETs in the past. I found that as long as the engine was maintained with fresh oil every 3K miles, and oil pan isn't dented up (SR20 has very low oil pick up and dented oil pans contribute to rod bearing failures) rod bearings seem to last fairly long.

If they start to knock, I will then do them, till then knock on wood they are good.

[maxnix]

I found that as long as the engine was maintained with fresh oil every 3K miles, and oil pan isn't dented up (SR20 has very low oil pick up and dented oil pans contribute to rod bearing failures) rod bearings seem to last fairly long.

Same on the VH45DE. I am sure you realize milling the heads will change your camshaft timing slightly.

Get some pillows for the heads. OUCH!
Modified by maxnix at 10:37 PM 10/14/2005

[elwesso]

Same on the VH45DE. I am sure you realize milling the heads will cahnge your camshaft timing slightly.

Get some pillows for the heads. OUCH!

What is that supposed to mean?

BTW I agree... Dennis has always said in his experience with the Qs that the rod bearings are the last things to go if the oil changes are done.. The most engines fail due to rod bearings because people wont change the oil

[texasoil]

Q45 engines (and all engines that have overhead cams ) are very sensitive to cambearing misalignment. Think about it--if you take variable amounts of metal off the bottom surface (its not perfectly flat when you start cutting), the resulting 'flat' surface will no longer be absolutely parallel to the cam bearing bores--which were very carefully bored to be STRAIGHT with the head torqued down. When you retorque the 'flat, but not parallel to cam bores' head, the top of the head and cam bores will no longer be straight. Cams DO NOT like bending and will break, cam bearings will scuff and seize, and you will probably wreck the engine.

Been there. Learned this long time ago on MBZ heads. They had replaceable 'cam towers' and special shim packs available from good dealers so you could fit the cam bearing height to within 0.002" max bow end-to-end, 0.0005" between any two bearings. When fitted correctly, the cam would spin freely with everything torqued down (no lifters or chains of course.)

On engines with non-replaceable cam bearing towers, you are screwed big time if you mill the head and it was not perfectly flat. You run a big risk of cam failure.

[BlackBirdVQ]

A good machine shop like I am using (build over 1000 Lexus/Toyota 3.0L V6 heads) can weld on new material and line bore the cam towers back to specs. I have been using this machine shop for years and I have NEVER had any problems with them. They acid dip the head for cleaning, and take off very little material to keep it within the FSM limits. I am sending them the heads the SAME way I got them off, WITH camshafts still bolted down to them. They will then mill the head with the cams on, perform all my needed and specified repairs- like magnafluxing it for any cracks, perform valve job if needed and install new valve seals. Heads usually come back looking like new from this company, and they are backed by a warranty.

I to have rebuild a few MB straigh 6s and V8s, my next engine job is on a 92 420SEL that needs a valve job. I know cam towers can be shimmed, but realistically, WHY ? A good machine shop is able to line bore them to perfect specs.

Line boring is a procedure of honing/borring multiple of something, like crank mains or camshaft towers. Perfectly set up honing stone goes in and makes each main or cam tower identical to the other. I get a print out of every spec on my heads, along with CFM the head flows.

Its not like I'm using a backyard mechanic to rebuild my heads, I have enough knowledge to do this myself (probably more Nissan experience than any tunner in IL), but I lack the equippment to do so. Plus I don't have the time to do this eighter.

[maxnix]

Don't know the specifications range on the Lexus/Toyota, but alot of the Nissan OEM manufacturing specifications on this engine are in the .0001 range. Must be ultra precise, not just Chevy good enough.

[Jeff Williams]

Here's some bling for your engine compatment.

[maxnix]

Gotta love that polished intake plenum!

Too bad it's not a driver, but no fenders only looks cool, does not work well in real world. Another billiard table car. Too bad.

[BlackBirdVQ]

Intake looks good, I just hope mine looks as good this Friday when I pick it up. Work on the Q is stopped for this week, I got traning at Honda/Acura school all week and even then I wouldn't get anything more accomplished. I'm debating on polishing out the front covers- timing covers, as they are hard to see anyways with the plastic covers on and cooling fan in the way. Valve covers are deffinitally going to be candy apple red- in true Nissan racing tradition

I will keep ya'll updated on my little project, I can't wait to drive it !

[5seryan]

Id love to come by sometime and take a look at all these goodies when you have a chance when its all good and done. just a quick trip from the burbs.

[BlackBirdVQ]

Actually I work right around where you reside, Naperville. I saw a Q45 once in Woodridge area on I88 like 2-3 weeks ago. I was flying to work and zoomed past one at bout 120MPH in my Q. Might have been you ?

[elwesso]

if it had the JDM TYTE red and silver paint, then it probably was.....

[3rd Q]

Blackbird,If the plenum turns out good, would you mind letting me know where you got it done? I've got a spare plenum and valve covers I'd like to customize.

Can't wait to hear how the head rebuild went!

Paul

[BlackBirdVQ]

I got a kid at work that does wheel refinishing in our company, he makes wheels like new ( I had all 4 of my old school JDM Enkei wheels done by him for my Maxima). Hes a horsepower junkie and does alot of polishing for his own ride, seeing how nice most of his work comes out, I asked him to do my intake manifold.

3rd Q I got a spare intake manifold if anything, I could make it bling for ya and you could just send me yours back- we could do like a CORE exchange type of a deal for the Q drivers here.

As soon as my intake manifold is done, I will share the joy with you guys (aka pic wise)

[3rd Q]

BlackBird,Cool. Just LMK.Paul

[RobertsnewQ]

Good job. Let us know how it turns out.

I get so sick of the "Nissan is the holy engine builder to the gods" stuff on here.

It's an engine. It has specs. It can be rebuilt. No magic.

As for the mystical ".000000000000001mm" accuracy, how do you think other engines are measured? Hint: Just as closely.

As for the cam towers, I've had them align bored on numerous engines. Works great.

I've heard of people having trouble finding the O-rings for the HLAs - Are you replacing them?

[elwesso]

But wouldnt you agree, unless you can DIY 90% or more, it is probably more cost efficient over the long run to byu a used engine????

[texasoil]

Good to learn you are dealing with a 'race quality' shop. Not many folks understand the importance of straight heads and true bearing bores. The difficulty with MBZ cams is the 'bearing towers' are not split so any 'line boring' enlarges the diameter, negating the effort to keep things straight and proper clearances. With 'split' bearing caps, the shop can 'face' the caps and then bore them to proper diameter -and a straight line parallel to the crank center line as it should be. I've seen LOTS of alloy cylinder heads messed up by standard automotive machine shops.

[BlackBirdVQ]

My intake manifold is bout 3/4 finished and boy it looks BLING, I mean you can see yourself in the finish. He wants 150 for the job and any of you are interested I can get another intake done by him- it takes him a week cause hes waaay to meticilous with his work. I have a spare intake so it shouldn't be any problem. I got a price of 140 bux to get my valve covers powdercoated in candy red, that is shipped for both of them. I think I will send them out next week- as I wanna get my spare VQ30DE-K valve cover done in the same color for my Maxie. I think the rebuild is going to take longer than expected and the car might not see the road till Winter time- when I fire her up. I keep on adding more n more stuff to the car that I wanna do- I'm measuring the engine compartment for some intercooler piping and wanna make sure I have enough room there for a set of GT28RS'. Everything goes planned I should have a VERY sick Q45 by the time 2006 IHRA season starts.

[5seryan]

Only if it was silver/crimson. In the past if you saw one in naperville the was silver and driving fast. that was me. I used to work at jimmy johns in downtown naperville.

[RobertsnewQ]

The difficulty with MBZ cams is the 'bearing towers' are not split so any 'line boring' enlarges the diameter, negating the effort to keep things straight and proper clearances.

There are two ways around this problem:1. Bearing inserts that fit the original cam and require a larger bore in the cam towers.2. Boring them oversize, pressing in an aluminum ring, and then align boring.

Since it is the middle one or two towers that are warped, generally the above will cure the problem. I've had it done on Ford 2.3 engines before.

Quote »I've seen LOTS of alloy cylinder heads messed up by standard automotive machine shops.[/quote]Me too. You need to have someone you can trust absolutely.

[RobertsnewQ]

[QUOTE=elwesso]But wouldnt you agree, unless you can DIY 90% or more, it is probably more cost efficient over the long run to byu a used engine????[/QUOTE

Yes, especially since Japanese engines wear so damn slowly I've seen SR20 motors with 300k on them and NO BORE RIDGE!

A used long block that's been resealed for a total cost of $1000 or so will do you just as good as a rebuilt for 100k or more...

[BlackBirdVQ]

ahh a fellow SR20 driver, hello

Ive rebuilt quite a few SR20s, owned alot of them and raced all of them...

My VH with 113K miles has zero cylinder ridge, and you can see the crosshatching pattern on the bores still. My project is really going slow right now, I am still waiting for my overhaul kit from Infiniti, and then I can send my heads out- hopping for Friday at the latest. After that I am sending my injectors out to one of my sponsors- Deatsch Werks for sonic testing, cleaning and testing performance to make sure my injectors are all in top shape. I really don't wanna dig into the motor again for atleast a few months, till its time for a bit of boost

I wanted to pull the Auto this week and rebuild it, but I don't wanna stretch my expensses as its already costing me bout 3K in parts and machine work to get this sucker rolln again. I am going to use the transmission for a bit longer, till I find all my needed parts for a Z32 5spd transmission swap.

Working on engines isn't strange to me, and my Q hasn't scared me a bit- hell I was excited that I was going to do head gaskets on it !

[GreenQ45a]

any news on the project

[elwesso]

zerothread?id=148134

[Haitian_King]

This thread makes me feel a strong need to go to automotive school. Or find an Infiniti Engine Expert who will mentor me.