Thought I should move this from the 'Journal' forum and update where the project is at. Wish I was at Coventry with everyone, but these things always take longer than anticipated, lol

 

20/01/2013

Having had the car for a few years now I have finally given in to the urge for more power.

 

The original engine in the car runs superbly only 66k miles with a proven Dyno run @ 357bhp, with boost jets and a uprated chip & air filter. Not bad at all for a 300ZX, but I was bitten by the bug and was set on going for more bhp and reliability, (I know why fiddle with it if it ain't broke). But having been lucky enough to have many nice high powered cars in recent years I wanted to keep the Zed long term and the engine is the first part of the project so it need's to be a good strong/reliable build.

 

After looking at various options of buying a part built engine form the US I decide to also keep my eyes peeled for the poteintial of purchasing an uncompleted project rebuild.

 

Back in March/April 2012 an ebay listing caught my eye regarding a nearly completed forged engine rebuild. The only problem with it was that the rebuild wasn't exactly completed by the most reputable of Zed engine builders known within the Zed world. In fact the seller had been caught up in horrific events where parts when missing, work was never finished and finally the garage was broken into and his engine was stolen. Retrieved from a nearby field 24 hours after going "missing". see here for a bit more http://www.300zx.co.uk/forums/showth...light=s+mochan

After talking with the seller for sometime we struck a deal and I waited for the day when the pallet with the engine would arrive.

 

It came with forged internals, Wiseco pistons, Eagle rods, ACL Duralite white metal bearings ARP main con rods and head bolts, Tomie 260 degree camshafts with solid lifters & harder springs, SARD 850cc injectors with a Border fuel rails/ new Turbo's, s/steel manifolds, new oil pump, heads polished, exhausts ports and valves shimed & lapped.

 

Didn't look all that great mind when it finally arrived to be honest, and I still had my doubts as to whether I had done the right thing in buying this.

 

 

 

After stripping down the engine as far I was prepared to take it anyway,

 

 

 

 

 

I wasn't going to attempt to go much further, so I thought it would be best to get this done properly!

 

So a call was made to Jim @ PowerZed to arrange a date to get everything to him in order for him to work his magic.

They (ams) get so heavily slated and anyone who has brought stuff from them with it on 3zc it's kinda annoying because there are plenty of parts they do make that are for the money worthwhile. So many pairs of there turbo elbows and manifold etc glaring around with no issues. Their 2.5" intercooler pipes are cheap as chips in comparison, I know fitment isn't great but for half the price personally I don't mind spending a few hours mucking about, there are some genuine horror stories though. I've very tempted with those intercoolers myself so I'm glad your experience was positive gives me more faith.

They (ams) get so heavily slated and anyone who has brought stuff from them with it on 3zc it's kinda annoying because there are plenty of parts they do make that are for the money worthwhile. So many pairs of there turbo elbows and manifold etc glaring around with no issues. Their 2.5" intercooler pipes are cheap as chips in comparison, I know fitment isn't great but for half the price personally I don't mind spending a few hours mucking about, there are some genuine horror stories though. I've very tempted with those intercoolers myself so I'm glad your experience was positive gives me more faith.

 

The issue with AMS in the US, is they view them as having taken someone else's R&D'ed product, copied it and made really crap copies which sell like hot cakes, while the company that spent all the money on R&D suffers due to lack of sales as their quality demands a higher price.

Well there's that as well yeah but you can't get any feedback that's not tainted by politics because of reasons such as what you've just mentioned. I'm not saying they are high quality or even quality probably on a par with the likes of other Chinese made components we all buy sometimes paying twice for it to be orange or blue...

Off to see Noel tomorrow for the final stage of mapping my car.

Can't wait to final get some boost!:thumbup:

Yup, it's a PowerZed/Turbonoz weekend of mapping, starting with yours :)

What were the results on this bigh?

Little bit of a set back I'm afraid. The Cometic head gasket failed, whilst being mapped. So it's still with Jim, awaiting a new gasket set. Next time round I will be using a Tomei HG set https://conceptzperformance.com/Cart/description.php?II=13851 as I have read a few horror stories about the Cometic ones.

 

Have a read of this http://www.twinturbo.net/nissan/300zx/forums/general/view/2560306/VG30-MLS-Head-Gasket-Comparison.html

That helped change my mind!

 

I know lots of people run them with no problems, and with more power than I'm running,but when you see the superior design of the Tomei one it's a no brainer!

Howard, I was under the impression (perhaps wrongly) that stock head gaskets are very tough and unless you are going

for *very* high hp are entirely adequate?

He's got over size pistons I believe Andrew

No my block hasn't been bored out. But you can run a bigger bore size gasket without it causing any problems

Oh I thought you were on 88mm pistons for some reason.

Oh that's as bit of a shit! Oh well at least it's in good hands, I have been looking forward to the results in this after the Hastle you have had

Little bit of a set back I'm afraid. The Cometic head gasket failed, whilst being mapped. So it's still with Jim, awaiting a new gasket set. Next time round I will be using a Tomei HG set https://conceptzperformance.com/Cart/description.php?II=13851 as I have read a few horror stories about the Cometic ones.

 

Have a read of this http://www.twinturbo.net/nissan/300zx/forums/general/view/2560306/VG30-MLS-Head-Gasket-Comparison.html

That helped change my mind!

 

I know lots of people run them with no problems, and with more power than I'm running,but when you see the superior design of the Tomei one it's a no brainer!

 

The gasket actually failed on the way back after the majority of the mapping had been completed :( I saw issues with Cometics many years ago in CA18DET engines.

 

That's 3 Zeds I know of with failed Cometic HGs. I know of plenty more without issues, but it's too big a risk to take IMO. It's definitely a power-related issue, up to 500bhp they seem to be fine. Much more than that, and their design simply can't withstand the elevated cylinder pressures. That's my take on it, anyway :)

 

Howard, I was under the impression (perhaps wrongly) that stock head gaskets are very tough and unless you are going

for *very* high hp are entirely adequate?

 

Indeed, the stock headgaskets are perfectly good for high power levels.

The finish that is required by Cometic for their heads is clearly specific. The general finish for conventional composite head gaskets is very rough compared to the "AR50"(Average roughness) finish required by Cometic. The AR50 finish is an almost smooth finish and its my opinion that many Cometic HG failures are due to the incorrect surface finish. Of course incorrect torque and excessive boost levels also contribute but that another issue.

...excessive boost levels...

 

No such thing! :D

 

Agreed it's too hit & miss to stick with cometic, I have one installed and it's not missed a beat, but will switch to Tomei for the next build - just in case. Stock will also be fine for 99.9% of use cases

The finish that is required by Cometic for their heads is clearly specific. The general finish for conventional composite head gaskets is very rough compared to the "AR50"(Average roughness) finish required by Cometic. The AR50 finish is an almost smooth finish and its my opinion that many Cometic HG failures are due to the incorrect surface finish. Of course incorrect torque and excessive boost levels also contribute but that another issue.

 

Not applicable in this case. By that I mean incorrect finish on the mating faces, incorrect torque or excessive boost levels.

 

Cometic gaskets offer little, if any, sealing advantages over the stock items.

So what is thier supposed advantage? I'd already decided that stock is suitable for my application but yeah just curious.

From CZP regarding the Tomei HG embossed openings around the oil and water channels,They also hold the distinction of being the only MLS gasket on the market to utilize a sealed firing ring around the combustion chamber, like OEM gaskets.

Cosmetic gaskets don't have any of these features

Edited October 18, 201411 yr by bigh

That's the tomei ones I take it?

That's the tomei ones I take it?

 

Yes sorry Stephen

That's ok bud, did the tomei ones go up in price from the cometic, I see z1 don't do the tomei ones?

Yes the Tomei ones are $430, Cometic $170 ish

Nice discussion on the hg, i contemplated getting the cometic and was confused on different thicknesses and the more i read though the more i was put off.

 

Upon reading i also came across the tomei ones and have seen no scare stories on the internet anywhere but pretty much the same was said about the oem ones, i plumped for oem like for like, as i have in excess of 500hp with no problem with the original one Nissan fitted in 1994.

Yeh that's sounds good to me, I'm aiming around the sorts of numbers you got first time round bud, so they should be good for me aswel. Not to mention oem hg is about $100 cheaper than even the cheaper cometic one.

That's ok bud, did the tomei ones go up in price from the cometic, I see z1 don't do the tomei ones?

 

They do do it. Whilst it's not listed, they can get it pretty easily. Tomei was a Platinum sponsor of ZNationals (I sat on the same VIP table as the president of Tomei) - both Z1 and Tomei have a great relationship. Speak to Jon or Chuck and they'll be able to get it.

 

- - - Updated - - -

 

Cosmetic

 

:rofl: ;)