Notices
VQ35HR Mods and Support related to the 2007/08 High Revving VQ

Bore out a VQ35HR

Thread Tools
 
Search this Thread
 
Old 10-28-2009, 03:40 PM
  #1  
Kil'Jaden
Registered User
Thread Starter
iTrader: (1)
 
Kil'Jaden's Avatar
 
Join Date: Jan 2009
Location: Fayetteville, NC
Posts: 26
Likes: 0
Received 0 Likes on 0 Posts
Default Bore out a VQ35HR

What's the feasibility of boring the engine out to 3.8L? How much money so you think to do it along with all the internals? Durability?

Anybody done it/have an idea of what specific internal parts would work best?

I've spent a lot of time trying to find a thread on this with no luck, but I am sure this has come up before.
Old 10-28-2009, 07:07 PM
  #2  
Z1 Performance
Former Sponsor
iTrader: (564)
 
Z1 Performance's Avatar
 
Join Date: Feb 2003
Location: Long Island, New York
Posts: 19,266
Likes: 0
Received 5 Likes on 5 Posts
Default

it will cost alot

durability? all depends who does your machining and assembly, and who does your tuning

who's done it on an HR? No one that I have seen. Several have done it on the DE, but the internals are different
Old 10-28-2009, 07:48 PM
  #3  
archangel72
Registered User
 
archangel72's Avatar
 
Join Date: Sep 2009
Location: winter haven, fl
Posts: 83
Likes: 0
Received 0 Likes on 0 Posts
Default

What would be the benifits of boreing it out vs stroking it out? GTM has a 3.8L stroker kit for the hr.

Last edited by archangel72; 10-28-2009 at 07:50 PM.
Old 10-29-2009, 05:32 AM
  #4  
Lakeside
Registered User
iTrader: (5)
 
Lakeside's Avatar
 
Join Date: Nov 2007
Location: Clifton Park, NY
Posts: 1,537
Likes: 0
Received 0 Likes on 0 Posts
Default

A stroker adds more wear and tear. Pistons speeds are higher! We race stroked motors in the APBA and IJSBA aka jet ski racing and engines need to be torn down and rebuilt more often due to the wear on the two and four stroke engines.

The Torque is amazing! But do you have the cash to rebuild it if compression drops or a bearing fails?
Old 10-29-2009, 06:09 AM
  #5  
Z1 Performance
Former Sponsor
iTrader: (564)
 
Z1 Performance's Avatar
 
Join Date: Feb 2003
Location: Long Island, New York
Posts: 19,266
Likes: 0
Received 5 Likes on 5 Posts
Default

Originally Posted by Lakeside
A stroker adds more wear and tear. Pistons speeds are higher! We race stroked motors in the APBA and IJSBA aka jet ski racing and engines need to be torn down and rebuilt more often due to the wear on the two and four stroke engines.

The Torque is amazing! But do you have the cash to rebuild it if compression drops or a bearing fails?
If a bearing fails or compression drops on any motor, you run into the same problem

Piston speed will depend on the stroke of the crank, and the rpm range of the engine - faster piston speeds are not a given by any means. Typically strokers have a lower rpm range than non strokers

A well built motor will be able to cope with this better than a stock engine can, as the quality of the components can be better (and lighter in many cases), as well as the tolerences of the bearings. The success or failure is in the quality of the components and the skill level of the machinist
Old 10-30-2009, 01:57 PM
  #6  
lee_dfw
Registered User
 
lee_dfw's Avatar
 
Join Date: Oct 2009
Location: Dallas, TX
Posts: 18
Likes: 0
Received 0 Likes on 0 Posts
Default

Going from 3.5L to 3.8L with all stroke will increase max piston speed about 8% and max acceleration 9% using the same length rods. Those numbers go down if you increase rod length on the stroker.

Not sure how much that matters.
Old 10-30-2009, 06:27 PM
  #7  
neverenough
Registered User
iTrader: (5)
 
neverenough's Avatar
 
Join Date: Apr 2007
Location: louisiana
Posts: 165
Likes: 0
Received 0 Likes on 0 Posts
Default

There is a twin turbo 3.8 hr being built right now. GTM is doing the build for me. Don't want to say to much to soon but it is happening now. There will be a thread keeping track of the build soon.
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
MM'08_350Z
VQ35HR
225
04-22-2021 09:42 PM
_koubie_
Engine & Drivetrain
5
09-20-2015 06:34 PM



Quick Reply: Bore out a VQ35HR



All times are GMT -8. The time now is 04:13 PM.