A community of enthusiasts dedicated to Nissan's SR20DE/SR20VE/SR20DET engines.
Start here: forum search. Be sure to search on what you're looking for before posting a new thread.
You are currently browsing the forum as a guest. In order to access special features, the image gallery, and post you will need to be a registered member. Registration is fast, simple and absolutely free so please, join our community today!
If you have any problems with the registration process or your account login, please contact the administrator.
Having a little bit of a look 'round at what can be done to make the Fujis perform a little better on a built motor when one is too poor for 4 into 1
The length of the Primaries is about 15", I haven't had a chance to measure the secondaries yet but they are looong.
I was wondering if having a custom secondary could add a little HP and was thinking of getting the following setup made:
Still stay with 2 into 1 but:
Increase the pipe size slightly of the secondaries
Shorten the length of the secondary pipes to 10 - 12 inches from where they meet the primaries
Have a 2 1/4 inch venturi straight after the merge flaring out to 2.5"
Have the 2.5" pipe then go on to the join so that the overall length of the secondaries stays the same as the original Fuji one.
Keep in mind that my exhaust system is a mandrel bent 2.5" with 2 resonators & a straight-through muffler. This is all guess work of course but, I'd like to know what our team of exhaust experts thinks.
Funny you should mention those figures charles... cos when I had my stock VE primaries and I had some custom made secondaries they were almost the exact dimensions you're quoting and I'm still sure that they went better than the fuji's did.
__________________
Anybody who cannot comprehend mathematics is not fully human. At best he is a tolerable subhuman who has learned to wash, cook food, and not make messes on the floor.
Cut the secondary pipes in half
weld on a good ( burns or SPD) 2-1 collector ( 2 3/8" choke)
weld on a good 2 3/8" to 3" long transition ( 6" transition length)
that should shift the power band up a lot higher and produce a lot more tq from 5000 up.
Its worth a shot to someone. and thats what i'd try on a 4-2-1.
Thanks Charles, I was hoping you might have some idea being the fella who's done the research on this stuff.
I noticed that virtually every one of the custom 4 into 1 VE headers (including your ones) on this forum seem to use a 1 3/4 inch pipe stepped to 1 7/8 but your production headers don't, does the step make much difference?
Seriously considering this now.. At some stage I may want to send my engine specs to Burns & get them to advise a collector or possibly a full 4 into 1 custom setup. lf the the current headers are going to be modded, they'd need to know the primary & secondary size on the Fujitsubos (anybody?)
The engine has std size valves & if I'm going to put more cash into this beast, I'll seriously consider going 1mm oversize which I guess could change the specs of the headers too.
Giving the size on the ports could be a problem 'cause they've been fiddled with. Here are some (courtesy of Adrian) pictures of the porting job that was done. What size to these look to be compared to stock?
Having not had much personal experience with different flavour VEs, I don't know if you'd consider that a mild or race port job.
Not to be an ass about it, but it doesnt even look like the Bowls were blended or opened up. the space around the valve is the part of the VE head where it needs the most help.
As far as really being able to help to really spec a header out, i would need to know the size of the bowls and how open the throat is.
I agree, entrance porting doesnt do as much as bowl work.
I definately agree, doesn't look like there was a valve job or bowl/pocket work. On my head, the opposite was done, valve job and pocket work with blending to the valve inserts. The entrance was left alone.
Not to be an ass about it, but it doesnt even look like the Bowls were blended or opened up. the space around the valve is the part of the VE head where it needs the most help.
With being the original owner of this motor, I paid quite a lot of money for this 'head-work', and have always 'bragged' about the port work, and the expense to get performance out of these motors to others.
Has the work done on this head helped or hindered performance?
All theya re saying is that the bowl work wasnt done. I would take it to another machine shope and have them do a full stage 5 type portjob along with a multi angle valve job. for samples, i would goto www.dprracing.com or here http://www.dprracing.com/SearchResults.asp?Cat=11
"There is one thing man should truly fear...it is the INDIFFERENCE of good men..."
My Set Up:
Motec Exhaust*Walbro Header*MSD Rims*Jim Wolf Custom Paintjob*Injen Tires*Mugen Glove Compartment*MazdaSpeed Bridgeport*Edlebrock Exhaust Bearings*Calum Power Mirrors.
Damn My Sentra Hauls!!! 93 Whp of PAIN!!!
Last edited by zerogravity : 06-13-2007 at 10:05 PM.
With being the original owner of this motor, I paid quite a lot of money for this 'head-work', and have always 'bragged' about the port work, and the expense to get performance out of these motors to others.
Has the work done on this head helped or hindered performance?
What would you suggest to do with this head?
Is it salvagable?
Looking at it & considering it was done 2 years ago (and as James points out, on a flow bench), it may just need some extra work in those areas where it's lacking right now.
Adrian, weren't you originally going to run bigger valves & then changed your mind? Reg may have started the porting with that in mind & then never finished it.
Looking at it & considering it was done 2 years ago (and as James points out, on a flow bench), it may just need some extra work in those areas where it's lacking right now.
Adrian, weren't you originally going to run bigger valves & then changed your mind? Reg may have started the porting with that in mind & then never finished it.
Nope, never was going to use the bigger valves!
I couldn't see the point when Bazza and Mike were telling me that the big valves flowed LESS!
And also was associated with the additional COST!
We all know that this project spiralled out of control on the money side of things...
I'm just a bit concerned as to why, after all of the 'research' done by various people, that there's a difference of opinion NOW?
Or just FARK it, TURBO it, that head looks like it'd flow more than enough.
You could possibly swap that head for someone wanting a well flowed VE head for their standard one, and start from scratch?
With being the original owner of this motor, I paid quite a lot of money for this 'head-work', and have always 'bragged' about the port work, and the expense to get performance out of these motors to others.
Has the work done on this head helped or hindered performance?
What would you suggest to do with this head?
Is it salvagable?
Entrance porting wont hurt a thing and is part of a normal port job. Just have the job finished and have an experianced ported open up the bowl and smooth the short side radius of the port with a good 3 angle valve job and a 30 degree back cut on the valves.
Don't worry, the head isnt ruined, just not done!
Also we can't totaly tell from the picture if the bowl was not ported, it just doenst look like it.
Ha ha.. this seems to have upset Adrian more than me. I'm not too concerned as I agree that it may just need some more work. If I continue developing the engine I was going to do that & some bigger valves anyway.
The person who ported the head is Reg Cook who is a bit of a local legend Nissan builder here. He's been doing it for years and tests everything on a flow bench so I doubt he hurt anything.
The head does have valve work, I have a receipt that has:
Port, polish antireversion etc and cut all valve seats & valves, triple cut, relap valves and blend seats
Not being a motor engineer, an explanation of what all that means would be a bonus
