Time for an engine rebuild?

shadowman

Well-Known Forum User
Hello guys,

First of all...apologies for the rather long story that follows...

I just want to put a question out there and hear your thoughts. I have a 1992 Fairlady Z (imported 300ZX). I've had her for around 10 years now and she has served me very well. The last few years she has been suffering from an oil leak which wasn't so bad i the beginning. That first appeared when I pushed her a little hard one day on a clear M3 to bracknell on the way to work. I stopped the car and could smell burning oil and a plume of wispy smoke coming emanating from under the driver's side door. It seems that oil was leaking and found its way onto the hot exhaust hence all the smokey fumes coming from underneath. It sounds bad but it wasn't that bad really unless I pushed her hard. Normal driving she was fine. Also it was only noticeable when driving for a long period normally on a hot day. A bit embarrassing when in a queue of traffic. As the leak seemed to be coming from the back of the engine I was told it was a ruptured seal.

Anyway I decided to leave it knowing that one day it would need attention but as it wasn't so bad I put it on the back burner...so to speak. This was around 5 years ago.

Fast forwarding to the last 3 years (a year of which she was on the driveway due to concerns with low oil pressure as we now) she is bleeding a larger volume of oil and I fine I am topping up oil a lot more frequently. This combined with low oil pressure ( which could just be a faulty sensor). Currently, the car is with my local mechanic who has seen and worked on her several times previously. However, this time they can't seem to move onto my car long enough to do the necessary work. They did try to locate the oil leak initially and seemed to have given up when they couldn't locate it. I did tell them the plenum would need to be taken off which I don't think has been done. The car has been with them since July last year now and they keep apologising, saying small jobs had become big jobs which has delayed them getting back to my car, all which I am sure is true. They are all old guys there and work on all kinds of stuff. A 300ZX is not the easiest of cars to work on but I wish they would just give me new news other than there have been further delays.

My dad always kept asking me if I had spoken to the garage about my car. My dad was never a car man but he loved my 300. My dad had a thing for V8's and land rovers and he always said my V6 sounded like a power boat. Since they've had the car my dad passed away. So I want my 300 back more than ever, not just because she is a great car but much more for sentimental reasons. I just want my beloved car fixed and back on my driveway or on the road where she belongs which I know would make my dad happy. I've been without her too long.

So I did some thinking and I am wondering if this is a good time for an engine rebuild? Considering the age of the car with only around 70k on the clock is it worth rebuilding the engine, changing out old parts for new, perhaps even increasing the power. I thought about doing this myself as a project but I don't have a garage or the space, just a shared driveway. So I am looking for someone to do this work.
I know the original power would restored after a rebuild but I might take the opportunity to get a little extra power out of her. I don't want to go crazy and turn a reliable strong engine into a problematic one with mad power output but maybe an increase from stock power to something like 400 or 450BHP? I don't kow what kind of cash it would take for such an increase but I thought why not take the opportunity to revitalise the old girl and bump up her power as well.

Can anyone tell me what sort of price range for a normal engine rebuild would be?
A rebuild with power increase would of course be a lot more expensive but as I said I'm not looking for anything crazy like 700 or 1000BHP.
And can anyone recommend a good garage who can do this work for me?
Does anyone think this is worthwhile?

Thoughts and comments appreciated.

Thanks everyone.
 

Mikey Bean

Well-Known Forum User
what other mods does the car have? if non you will need other upgrades to get the 450 ish power. but just on the engine side to make it handle that power you should set around £2000 aside. this covers things like forged pistons, cometic gaskets stronger bearings etc etc. thats labour included too. prices will vary from garage to garage but thats ball park figure for the last one i did :)
 

shadowman

Well-Known Forum User
what other mods does the car have? if non you will need other upgrades to get the 450 ish power. but just on the engine side to make it handle that power you should set around £2000 aside. this covers things like forged pistons, cometic gaskets stronger bearings etc etc. thats labour included too. prices will vary from garage to garage but thats ball park figure for the last one i did :)

Well engine-wise it doesn't have any mods apart from really basic things like braided fuel lines, a performance radiator, an aftermarket filter up front to replace the huge stock one that stopped it from breathing more efficiently. I had a mongoose exhaust fitted as well to aid engine breathing. She has coilovers around and that's about it. If £2000 is the ball park figure then that's the reality. I thought costs would probably be in that region to be honest. I'd want the engine bay painted as well. I figure why not once the engine is out.
 

Mikey Bean

Well-Known Forum User
again with painting the engine bay there are different ways of going about this. there is pulling everything out and painting the lot, but given you cant see 99% of it most go for just painting the bits you can see. here is one i currently have in the workshop. customer just wanted it tidy up and this was the cheapest option for them

before_zps0f87a377.jpg

after_zpsb0fadc63.jpg
 

Mikey Bean

Well-Known Forum User
and back to the engine you would need to look at bigger intercoolers, and injectors with a map to run them. and if tubbies are still original it would be wise to at minimum get a rebuild with 360 bearings and bigger oil seals. ive just done one with similar spec and it has just run 430 bhp on dyno at 14psi so had plenty more if needed.
 

shadowman

Well-Known Forum User
and back to the engine you would need to look at bigger intercoolers, and injectors with a map to run them. and if tubbies are still original it would be wise to at minimum get a rebuild with 360 bearings and bigger oil seals. ive just done one with similar spec and it has just run 430 bhp on dyno at 14psi so had plenty more if needed.

Thanks for the pics. I guess I could just go for the option to paint the parts you can see. But I would probably paint the whole lot to be honest.

The turbos are the original models which I believe are the garrett type so all as stock. I didn't realise the turbos could be upgraded as well. I would hate to rebuild them for a larger power output and end up with turbo problems down the line. The last thing I want is turbo issue down the line. As you say this is the bare minimum required for power increases with the original turbos.

The car is an auto by the way so I don't know if there are implications for keeping it so or just easier to do a manual conversion. I'd prefer to keep the auto transmission and strengthen the auto transmission components if need be.
 

Mikey Bean

Well-Known Forum User
auto is ok for around 450 bhp. a few people are running at this level with no issue and some running more. if you wish to keep tubbies as they are and not touch them i would keep power around 400 bhp max to make them last. anything more and its rebuild time really. and with this being the case stock injectors with a good map can handle that. so just intercoolers really needed. oh forgot to mention a boost controller too :). but there really isent much needed to get these cars to that sort of power :)
 

shadowman

Well-Known Forum User
auto is ok for around 450 bhp. a few people are running at this level with no issue and some running more. if you wish to keep tubbies as they are and not touch them i would keep power around 400 bhp max to make them last. anything more and its rebuild time really. and with this being the case stock injectors with a good map can handle that. so just intercoolers really needed. oh forgot to mention a boost controller too :). but there really isent much needed to get these cars to that sort of power :)

The auto transmission being able to take 450 is good to know :) 400BHP is quite an increase from stock but that extra 50 BHP is very tempting. Thanks for responding Mikey you have given me a lot of food for thought. I appreciate all the info. I will get back to you.
 

shadowman

Well-Known Forum User
any time mate, im here if you have any questions.

Thanks mate. By the way forgot to mention that some HKS blow off valves were also installed just to ease pressure on the stock turbos. The idea was to increase turbo longevity. Now I find myself toying with the idea of replacing the turbos altogether with more powerful ones. This is kind of the reason why I didn't want to get too involved in engine mods in the first place. I'll start going upgrade mad.

Thanks again
 

Gonzo12c

Active Forum User
Hello and welcome back with your zed :)

Just to add in my expertise, to look at reaching a reliable 400/450 bhp including a rebuild I'd say 4k minimum. Price is always dependant on quality of parts and service that you pay for. Build an engine on the cheap and you are getting what you pay for. Even second hand engines seem to have the prices being pushed up at the moment.

On reaching higher BHP's a lot of it comes down to the induction and exhaust side of things so the engine can breathe. Add in a good tuner and quality mods then you have a reliable build otherwise sadly it ends up being another zed with another knackered engine being broke up for spares.

As you are looking to rebuild I would look to go for Wiesco pistons and Eagle rods as the price comparison against OEM is surprising. Then potential for 360 bearing turbo rebuild (£500 ish cost) or grab a bargain set if tubs that come up for sake now and then as I did with my HKS. Fuelling then is setting you back more for 555 injectors but the supporting mods of intake, intercooler and exhaust need to be there otherwise it's pointless.

There is a wealth of expertise hanging around these forums just be sure to do research as there is so many varied opinions on parts to use and such however a lot of this is secondhand knowledge from some guy down the pub that fitted these and so on.

Mikey above is on a small list of people that I consider to be knowledgeable and competent on Zeds as there is quite a lot of clowns about working on Zeds.

Marty
 

shadowman

Well-Known Forum User
Hello and welcome back with your zed :)

Just to add in my expertise, to look at reaching a reliable 400/450 bhp including a rebuild I'd say 4k minimum. Price is always dependant on quality of parts and service that you pay for. Build an engine on the cheap and you are getting what you pay for. Even second hand engines seem to have the prices being pushed up at the moment.

On reaching higher BHP's a lot of it comes down to the induction and exhaust side of things so the engine can breathe. Add in a good tuner and quality mods then you have a reliable build otherwise sadly it ends up being another zed with another knackered engine being broke up for spares.

As you are looking to rebuild I would look to go for Wiesco pistons and Eagle rods as the price comparison against OEM is surprising. Then potential for 360 bearing turbo rebuild (£500 ish cost) or grab a bargain set if tubs that come up for sake now and then as I did with my HKS. Fuelling then is setting you back more for 555 injectors but the supporting mods of intake, intercooler and exhaust need to be there otherwise it's pointless.

There is a wealth of expertise hanging around these forums just be sure to do research as there is so many varied opinions on parts to use and such however a lot of this is secondhand knowledge from some guy down the pub that fitted these and so on.

Mikey above is on a small list of people that I consider to be knowledgeable and competent on Zeds as there is quite a lot of clowns about working on Zeds.

Marty

I don't want to cut corners with a job like this. If 4k you say is the minimum to spend on quality parts then that's what I would spend. If I had garage space and tools I would do the job myself. I've never attempted any kind of rebuild so I know it would be a very steep learning curve. But I've always enjoyed a challenge, not to mention saving loads of cash in going it alone... with help :)

Thanks Marty. I will go away and do some serious thinking on this.



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Gonzo12c

Active Forum User
Just a point to note as well there is an engine builder in the south that I'm pretty sure is about 3k labour to build an engine as a close friend of mine enquired about having his built that already had the bottom end built. I couldn't think to pay someone that amount to build an engine and am lucky enough to have the means to do all my work myself so have alot of fun doing custom jobs.

You will get done very good information and advise on this forum if you require it. To gauge prices for parts, the majority of parts would need to be imported which is what a lot of people do. For this I would recommend http://www.conceptzperformance.com as the most helpful and best source of aftermarket parts overseas.

Marty
 

Mikey Bean

Well-Known Forum User
i agree with marty on most but not cost, the one i have just finished had wiseco pistons, acl bearings, cometic gaskets turbos with 360 bearings. a lot of people in the z scene for some reason believe with these cars you have to pay a lot of money for work doing. its this attitude thats allowing some people to put prices up. i run a normal car garage but have a good knowledge of the z32 so why would i charge more just for working on them. i charge the same as i would if it was a fiesta for an engine. they arent as bad to do as most think. dont get me wrong i still make half decent money from building them but im not here to rip anyone off. i havent had anyone ever say im a rip off or i charge too much and i plan on keeping it that way. :)
 

shadowman

Well-Known Forum User
i agree with marty on most but not cost, the one i have just finished had wiseco pistons, acl bearings, cometic gaskets turbos with 360 bearings. a lot of people in the z scene for some reason believe with these cars you have to pay a lot of money for work doing. its this attitude thats allowing some people to put prices up. i run a normal car garage but have a good knowledge of the z32 so why would i charge more just for working on them. i charge the same as i would if it was a fiesta for an engine. they arent as bad to do as most think. dont get me wrong i still make half decent money from building them but im not here to rip anyone off. i havent had anyone ever say im a rip off or i charge too much and i plan on keeping it that way. :)

Well I will never argue with anyone charging a cheaper price but I really don't want corners cut on a job lije this.

Forgive me for asking for clarification on this but it was mentioned that for 450 BHP I would need to have the stock turbos rebuilt with 360 bearings and bigger seals? Would this ultimately shorten the lifespan of the turbos? Would it not be better to buy bigger turbos? Probably a silly question


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Gonzo12c

Active Forum User
Yes quite simply as it will a lot easier to achieve higher HP with aftermarket turbos. Thing is cost and you start getting into the price range of at least over 1k for new aftermarket turbos and secondhand they come around every leap year. The question is where do you stop. I have an engine build that was over 10k to build so a lot of research and comparing if parts and prices needs to be done so that the parts complement each other.
 

Mikey Bean

Well-Known Forum User
as he says pushing them will shorten the life but if looked after they should last a long time. but if money is no issue then yeah bigger tubbies is allways better
 

shadowman

Well-Known Forum User
as he says pushing them will shorten the life but if looked after they should last a long time. but if money is no issue then yeah bigger tubbies is allways better

I wouldn't say money is no issue but bigger turbos definitely.


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