Jump to content
HybridZ

Destroking a VQ35 for Bonneville


jgkurz

Recommended Posts

Hi Folks, I am helping a friend with a new Bonneville Land Speed project. The car is a F/BGR roadster. I believe the current record is 201mph. The car has been on the salt in the past but does not have an engine. The beauty of the roadsters are that you can run any engine you want as long as it complies to the displacement, fuel and power-adder rules. We have FREE access to several VQ35's which is a good thing. The bad thing is that we MUST not exceed 3.0L. The latest idea is to acquire a Nissan Motorsports VQ30 crank and rods which will get us to roughly 3.15L. To get down to 3.0L we are considering offset grinding the crank. Our desire is to use the VQ35 block due to the larger bores and abundance of parts. The machine work is being done pro-bono so we are not concerned about cost for that aspect.

 

I'm posing this to HBZ to see if anyone has a better idea? I'd appreciate any comments.

Link to comment
Share on other sites

If you can find a VQ23DE (it actually exists in asian markets), the crank has a 69MM throw.

 

I knew the VQ23 existed from the Wikipedia entry but so far it's not been easy finding main journal specs on the VQ engines. Using a VQ20 - VQ25 crank may be the way to go but we need to somehow verify that the smaller crank will work in a VQ35 block. So far this link is the best I have:

 

http://en.wikipedia.org/wiki/Nissan_VQ_engine

Link to comment
Share on other sites

according to that link, the VQ20 through vq30 all use the same stroke (73.3mm), except the 23, which has a 69mm stroke.

 

Good point. I'll start looking into whether the VQ23 crank will fit in the VQ35. If anyone knows where to look for this info let me know.

Link to comment
Share on other sites

Using this calculator I found that the VQ23 crank would be ideal. Now I just need to see if it will fit in a VQ35 block. Thanks Mack!

 

http://www.bgsoflex.com/displacement.html

 

VQ35 Stock:

 

* Number of Cylinders are = 6 to 1

* Piston Diameter = 95.500 Millimeters

* Piston Oversize = 0.000 Millimeters

* Engine Stroke = 81.400 Millimeters

* Computed Engine Displacement (CID) is 213

* Computed Engine Displacement (Litres) is 3.5

* Computed Engine Displacement (CC) is 3498.5

 

 

VQ35 with VQ23 crank:

 

* Number of Cylinders are = 6 to 1

* Piston Diameter = 95.500 Millimeters

* Piston Oversize = 0.000 Millimeters

* Engine Stroke = 69.000 Millimeters

* Computed Engine Displacement (CID) is 181

* Computed Engine Displacement (Litres) is 3.0

* Computed Engine Displacement (CC) is 2965.5

Link to comment
Share on other sites

Does the VQ40 use bigger stroke and bore than 35? Haven't looked. If so, since the 40 is essentially an HR block with taller deck, if destroking is the goal, sounds like the Vq40 bock with the 35hr crank would be the way to go.

 

that would still likely come out to over 3 litre displacement if I read the strokes right. The aim is a VQ35 block which is free to the OP reduced to 3.0 displacement.

Link to comment
Share on other sites

Does the VQ40 use bigger stroke and bore than 35? Haven't looked. If so, since the 40 is essentially an HR block with taller deck, if destroking is the goal, sounds like the Vq40 bock with the 35hr crank would be the way to go.

 

I thought the HR had the same deck as the VQ40? The way I read it, Nissan altered from the 35DE to the HR by adding the motor plate setup at the crank end and increasing the deck height (essentially using the VQ40 block) to give a better rod/stroke ratio.

 

They may have not been increased all the way to VQ40 deck height, but while the Nissan tech is paying attention, no sense in not asking questions ;)

 

...I want to see this done, I think the VQ engines have some of the best designed cylinder heads around right now.

Link to comment
Share on other sites

Thanks everyone for the VQ40 suggestions, but we literally have five complete VQ35 engines to use/pick from. Since we are budget minded we will try to make the project work without going to the VQ40. Great suggestion though...

 

I have some feelers out for a JDM VQ23 crank, short block, or worst case a full engine. Hopefully something will turn up.

 

VQ23DE

 

200px-NissanVQ23DEengine.JPG magnify-clip.png

Nissan VQ23DE engine installed in a 2004 Nissan Teana J31

 

 

 

 

The VQ23DE is a 2.3 L (2349 cc) engine equipped with CVTC (Continuously Variable-valve Timing Control). Bore and stroke are 85 mm and 69 mm, with a compression ratio of 9.8:1. It produces 173 PS (127 kW; 171 hp) @6000 rpm and 166 ft·lbf (225 N·m) @4400 rpm.

 

 

It is fitted to the following vehicles:

 

Link to comment
Share on other sites

http://www.trademe.co.nz/Trade-Me-Motors/Cars/Nissan/auction-236679084.htm

 

we get a lot of japanese imports here, both new and used cheapies. A quick check of trademe brings up a teana 2.3 and the same car is sold here new as the maxima. Want me to ask a local wrecker to have a look around on the wrecking inductry database for teana/maxima 2.3's that are being wrecked? Might be able to locate a wreck with a 2.3 motor here to pull a crank form.

Link to comment
Share on other sites

kiwi303, I have an inquiry into a guy that deals with JDM engines here on the west coast USA. If he's doesn't turn anything up I take you up on your offer. Thanks for the help.

 

 

http://www.trademe.co.nz/Trade-Me-Motors/Cars/Nissan/auction-236679084.htm

 

we get a lot of japanese imports here, both new and used cheapies. A quick check of trademe brings up a teana 2.3 and the same car is sold here new as the maxima. Want me to ask a local wrecker to have a look around on the wrecking inductry database for teana/maxima 2.3's that are being wrecked? Might be able to locate a wreck with a 2.3 motor here to pull a crank form.

Link to comment
Share on other sites

I posted off a couple of emails last night off to some parts departments at the local nissan dealers. One came in today for $1916 NZD + tax or $1534.78 USD including tax after conversion on xe.com, ex japan.

 

expensive! It will be interesting to see what your contacts come up price wise.

Link to comment
Share on other sites

I posted off a couple of emails last night off to some parts departments at the local nissan dealers. One came in today for $1916 NZD + tax or $1534.78 USD including tax after conversion on xe.com, ex japan.

 

expensive! It will be interesting to see what your contacts come up price wise.

 

I assume these prices are for a brand new crank? Thanks for checking!

Link to comment
Share on other sites

I wasn't originally aware of the 3L limit or the abundance of VQ35 blocks, but I am still very interested in the project, so keep us posted. I would definitely go with your original idea of the vq35 block and heads, they are some of the best out there. Big ports, straight runners, pick up big hp with pressurized intakes.

Link to comment
Share on other sites

I assume these prices are for a brand new crank? Thanks for checking!

 

 

Yup, brand new ex Nissan Japan factory stock.

 

 

 

The wrecker I emailed (NZ's largest Nissan specialist wrecker) responded that so few 2.3 Maximas were sold in NZ since most were 3.0 models, combined with the used imports only having started showing up recently that they couldn't source a 2.3 crank.

 

Japan has tax penalties on cars older than 7 years, which depreciates 7 year old cars a lot, so NZers being a nation of cheapskates, import a LOT of 7 year old ex-japan cars, but the VQ23DE is less than a decade old. So there aren't as many as there will be in another few years when the flood of Teanas will probably hit it's stride :P

 

Hope this helps.

Link to comment
Share on other sites

Good news... It looks like Nissan Motorsports has a crank for just our purpose and it's only $400.00. For some reason it wasn't widely known since it's not in the NISMO catalog. At least that's my understanding. Apparently the VQ35 de-stroke to 3.0L is common in SCCA GT2. Thanks to everyone for your comments.

 

Next technical hurdle is getting the Darton Sleeves installed so the open deck is stabilized.

 

http://www.dartonsleeves.com/mainpage.htm

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...