Upgrade valve springs

[SamJulian]

Hi all, i've done a bit of searching around but not found a definitive answer.

 

I've got a set of Tomei Procams on the way for my '04 DE, 264° duration and 10.5mm max lift. Now some places i look it says the Procams are designed to be used with a valve spring upgrade, and most other places say its only needed with lift higher than 11mm.

 

Could anyone shed some light on this? And wether or not i would need to upgrade the retainers aswell?

 

Now next part of the question, i'll be running in a fresh engine with new piston rings etc then getting it mapped on the Haltech after 1000miles or so, so when it says the 'valve timing has already been adjusted' on the new cams I should be safe enough to run them without mapping for those running in miles?

 

Thanks, Sam

[evilscorp]

Stock valve retainers should be fine, as for the valve springs I would expect an upgrade would be advisable. The BC cams say they need their springs (probably marketing) due to the increased load of the larger opening and rpm raising that come naturally with big cams.

The car won't run well without a tune but you should always check timing and make sure there is no valve interference. As for if it will run. . . probably but not well.

[OllyB]

The cam manufacturer will be able to recommend what rate springs should be used. Go with their advice.

Edited April 1, 2017 by OllyB

[Ekona]

Who is doing the install? For peace of mind on the warranty side of things, I'd go with whatever our installer says.

If you're doing it yourself, then I agree with Olly and go with the manufacturer's advice.

[350Butcher]

Hi Sam,

 

Just fitting a set of tomei cams to my engine so have just been in the same position. Tomei do only recommend changing springs over 11mm lift probably as stock springs fully compressed height is too high to allow the increased lift. So you could run stock springs with the cams you (and I) have. However I changed my springs for 2 reasons, firstly the increased valve seat pressure is no bad thing and secondly if when you do you build you recut your valve seat you'll reduce valve seat pressure as a result and therefore uprating the springs will maintain where it needs to be.

 

Retainers will be fine to use unless you want to pay £££ for the titanium replacements to save a bit of weight on the valve train.

 

The engine will time up and run fine with the new cams installed and be all good while you run in too. You will only get the benefit of the cams after your remap though but as you've got to run in the engine first at low load and low/medium revs this makes no difference to you.

 

Make sure you post an update on how you get on with your build.

[SamJulian]

Thats perfect, thank you very much

 

Torqen have a good price on the Brian Crower springs so i'll order a set of them up later on and stick with the OEM retainers, will give me a chance to re-cut the valve seats as you said and have a bit of a play with the ports.

 

Will definately be getting remapped after so i'll start a build thread, i'm looking forward to see what it puts down.

 

Spec when its finished:

 

-Tomei 264 cams

-BC valve springs

-Manley H Beam rods

-ARP fasteners throughout

-ACL bearings throughout

-Port and Polished heads

-Re-cut valves

-Oem pistons with new Nissan rings

-Moterdyne plenum spacer

-New Rev-up oil pump

-Headers, de-cats, y-pipe, Japseed system

-Lightened single mass flywheel

-MAF delete for full 3"intake + ITG filter

 

Plus few other reliability bits like Stillen high capacity sump etc. Should be interesting

 

Thanks, Sam

[SamJulian]

Oh and Haltech Platinum management!

[350Butcher]

No probs.

 

Sounds like a decent build you're doing and well done for being another wanting to stick with N/A! Its hard to not get obsessed with the numbers and I'm sure it will make a good gain but like my build it'll be the way it drives after that'll be most impressive, so much more responsive and more willing to access the power it has that its worth all the work involved.........plus leaving a stock car wondering which way you went of course.

 

It may be on your list anyway but give your crank and clutch assembly to your machinist and get them to balance the whole lot as one, the rods should be fairly well matched in weight from factory so you'll have a nice bottom end (sounds wrong) that's happy at high revs, doesn't cost a fortune but makes a decent difference.

[SamJulian]

Funny you should say that actually, the engines had to come apart as a result of a low comp turbo build that i bought as a conplete package. Single Gt3528r, full homemade kit, fully forged block with Wiseco pistons.

 

It worked to an extent, and was making in excess of 400bhp but very spikey and i was never happy with it, never ran 100%, couldnt keep on the power for durations like you can NA, and the homemade piping showed signs of breakage very early on.

 

Going back NA because i always wanted too before, plus i've got half the parts already i only needed to buy cam, valve springs and OEM pistons really. Want the driveability back so i can use it on trafk again properly

 

And balancing the crank is on my list but i'm struggling to find anywhere local to me that does it without charging stupid money, is it going to be a problem revving around 7.5k without balancing? My theory was the Manley rods are closer weight matched than the OEM rods were, and the cranks are internally balanced from factory to an extent that people happily remap the rev-ups to 7.5k in standard form?

[Mark@Abbey m/s]

Hi ,

 

if your changing piston/rod weight on a V6 it will need balancing.

 

We use a company called Basset Down in Hungerford they balance all our engine components.

[350Butcher]

Sounds like it'll be a good job done then and you can enjoy the car again, a spikey poorly running turbo is horrible and so frustrating to drive.

 

Good that the rods are already in there for you! You'de be surprised how far out stuff is once you bolt it all together though, so the crank might be balanced but once you stick the clutch on it it throws it all out getting it done as it will run in the engine fully built up it the only worth while way. I was really shocked how much meat was removed to balance up my Evo crank/ clutch assembly.

 

I know its not local to you but Roland Alsop in Chobham, Surrey is the place I've always had do my machining work and they are top guys here's a link to check out them out, would cost £250 ish+Vat

 

http://www.rolandalsop.com/index.php?option=com_content&view=article&id=5:hines-dominator-crankshaft-balancing-machine&catid=2:our-workshop-machinery&Itemid=6

[SamJulian]

Yeah i cant wait, it was fairly mental but was going to take alot of money to get it all done properly and i ended up buying an Rx7 last year so that idea quickly went out the window.

 

And thats not soo bad! I was getting told some rediculous prices which was what was putting my off slightly. I'll have to do some digging for a decent machine shop down this way and pull my crank out over the weekend

 

Thanks again

[350Butcher]

Not a cheap job like building up an N/A engine you mean!!

 

Suppose worst case you can just pallet the stuff to somewhere to get it done. I've driven from Warwick to Surrey just to get my stuff done by people I trust and know do a proper job.

 

Good luck with it all