M35 Engine Upgrade

[scotty nm35]

I'm planning for a new engine as I have no Idea how reliable the VQ25det engine will be at the current power level. I would love to lean on it some more, but I need a built engine to replace it if and when it dies.

The choices I have are to either stroke the 2.5 Teps style or try and find a suitable 3.5 block to build and take some abuse. I guess the 2.5 would be easier to engineer or pass at Vicroads? Short stroke and larger piston appeal to me, 3L perhaps?

I'm sure you have all seen the 3.5 rod/piston sets on Ebay in the states, some of which are good for 250hp a rod apparently, this seems like the cheapest option and as I plan to do most of the work myself it could work out to be a fairly cheap upgrade. The block being taller shouldn't cause too many headaches as I can make a new plenum and I would need a new fuel set up anyway I guess.

The planned engine will be high compression, say 10.5 - 11:1 and run good boost levels still as it will be E85 dedicated. Not sure what single turbo would suit either combination, possibly GT35?

That should get the boat moving.

[richzx]

I think you should go for a Vq30Det and swap the intake over from the VQ25 so it goes to the drivers side. A 3L motor should have a lot of extra roque over the 2.5 and the 3L is already built to take turbo from the factory and there is plenty of aftermarket support. A few people are getting good power out of the VQ30 without issue thus far. I know on paper the VQ30 doesn't look as good but that is probably ecu related or cams but it's essentially the same motor. Plus, VQ30's are pretty cheap. I would hazard a guess that the 3L could be run on your existing ecu as well especially with the emanage. I know you can run a 2jzgte on a 1jzgte ecu and sensors and it 'learns' the fuel map for the bigger injectors (370cc versus 440cc). Personally I would always go for the factory turbo motor as it's been built to run boost.

[zei20l]

VQ30DET is an older motor thats why they are cheaper.

id rebuild a VQ25DET and stroke it if it were me, but if you want to go bigger, just get the VQ35DE and build it for boost

[iamhe77]

Don't bother swapping the engine mate, you have heard it from me before and I will say it again, stroke the VQ25 using the TEPS 3.6L kit and then up the compression

Will be an easier and quicker build than a VQ35 and probably more reliable too.

VQ30det? Nah, stick with the 2.5L "treasured" engine.

EDIT: on second thoughts, you could always buy a cheap, used VQ35de and sell the VQ25 to a certain local who wants to stroke it to 3.6L .... Yeah, definitely go the VQ35 lol

Also, check your inbox for a couple of options if you want to go the VQ35

Edited August 9, 2010 by iamhe77

[richzx]

What does it matter if the VQ30 is older? If the motor is in good condition then it shouldn't matter and you could possibly build a hybrid 25/30 if the VQ25 heads were better and those heads on a VQ30 bottom end may give you the compression you're after. A built motor is going to cost a bit with machining, parts etc and then what gearbox behind it? I don't think Scott needs to throw big dollars at an engine that will suit his power goal. A GT35 on a 3L will be plenty I would think and it's been done before a couple of times in WA with success. It's always nice to have something unique but that always comes at a cost. I think you would be asking a lot of an untried combination with a high compression, big turbo build. If you have deep pockets, go for it but I would go for the tried and tested option personally, but hey I like things to be as easy and bolt on as possible where I can get away with it.

[iamhe77]

Couldn't agree more (cost effective & as close to bolt on as possible)

Which is why I am working on getting as much info on this 3.6L stroker kit (also raises compression slightly)

VQ25 head on a VQ30? Nice thought (sort like an RB30det), but bolt on?

VQ30det - Bore = 93mm, Stroke 73.3mm

VQ25det - Bore = 85mm, Stroke = 73.3mm

Edited August 10, 2010 by iamhe77

[richzx]

Fair point I didn't check the bore on the 2 engines and thought thextra cc was from stroke rather than bore. Anyway, I guess I'm just thinking along the lines of what I would do if I was in Scott's position. $2k for a front cut, keep what he wants and sell of the rest to reduce the cost and it would be more of a bolt in proposition. Hopefully Scott will chime in with what he wants to do here and I'm guessing his mind is somewhat made up? I'm excited for him whatever he chooses but I know cost wise for myself I would go the way I have mentioned but I don't want heaps of power either, in my experience too much power and everything breaks, the car's off the road always fixing something.

[scotty nm35]

Well the Kewish built box should be good for 600whp according to the research I have done. It all depends whether I leave the standard ecu in place to control the throttle. The rest of the drive train should be fine I hope.

I want a built motor mainly for its long life. There is a chance these stock motors could handle the power but for how long? This is going to be an every day driver so strength and reliability is high on the list.

The 3.5 is taking the easy way out to some extent, it will make the power easier, allow higher compression and cheaper build parts. I dont even know if I can get pistons and rods for the 2.5 let alone the 3L. For the 3.5 they are available in so many options, like a lolly shop.

Cam, this engine will stay in the shed as backup I think.

[richzx]

I'm pretty sure OkBanana in his build said there was a heap of aftermarket support for the VQ30 in the USA. Anyway, it sounds like your mind is made up so let us know how you go.

[scotty nm35]

I'm pretty sure OkBanana in his build said there was a heap of aftermarket support for the VQ30 in the USA. Anyway, it sounds like your mind is made up so let us know how you go.

Far from made up, if there is huge aftermarket support why cant I find many parts? I will have to search some more.

VQ30, being an older engine, the sensors may not work with the M35 ecu. Im leaning toward using the stock block for that reason.

[Angus Smart]

Whats the bore and stroke on a v35 engine?

[iamhe77]

Far from made up, if there is huge aftermarket support why cant I find many parts? I will have to search some more.

VQ30, being an older engine, the sensors may not work with the M35 ecu. Im leaning toward using the stock block for that reason.

lol, try Googling "VQ30det performance parts". You should find some decent items including your beloved Pauter rods

Whats the bore and stroke on a v35 engine?

Bore = 95.5 mm

Stroke = 81.4 mm

Edited August 10, 2010 by iamhe77

[Angus Smart]

lol, try Googling "VQ30det performance parts". You should find some decent items including your beloved Pauter rods

Bore = 95.5 mm

Stroke = 81.4 mm

Pauter make some damn fine rods, i have some in my Gtr.

cheers for that. using a 35 crank in the 25 block etc would that work? i did discuss this with my engine builder when i first took the car there to drop off the rb parts.

[zei20l]

which V35 engine? they also came with 3 sizes of VQ motors

[iamhe77]

Pauter make some damn fine rods, i have some in my Gtr.

cheers for that. using a 35 crank in the 25 block etc would that work? i did discuss this with my engine builder when i first took the car there to drop off the rb parts.

It would appear so

VQ35 cam, crank & rods in the VQ25det... among others

Edited August 10, 2010 by iamhe77

[richzx]

Scott, check this thread out.

http://www.skylinesaustralia.com/forums/Vq...tt-t283253.html

[Angus Smart]

Ah sweet i though i remembered reading that somewhere..

Prices are USD

[scotty nm35]

That is the benefit of going to the 95.5mm bore, the pistons are the same as 350z. I cant find a cheap VQ30det block but I have found a VQ35 cheap that needs a rebuild.

Those prices seem very reasonable. I could perhaps get away with a 5 grand build...

[Angus Smart]

Yeah i have delt with them before too, they are quiet good.

was the cheapest place on the web i could find for Mahle pistons/Pauter rods.

[scotty nm35]

Yeah i have delt with them before too, they are quiet good.

was the cheapest place on the web i could find for Mahle pistons/Pauter rods.

Where are those parts from? Like I said, I want to over engineer the block. It would be good if I could build something to easily handle 500wkw but run less boost (most of the time). This engine probably wont stay in this car forever. I would love to slide it into an s15 or something one day.