Jump to content
SAU Community

Recommended Posts

Hi all, new here, first tech post,  be gentle!   Been lurking a bit reading of late, hope someone can help.

My 'problem' car is a 1994 Maserati Ghibli II 2.8 V6 biturbo.   Similar vintage to the R32/33 and similar numbers - 287bhp@6000rpm/305ftlb@3500 with 0.9bar (~13.2psi)  boost.   Limited support and tuning help for them here, as you can imagine, plus I'm in the bush.   4-valve bucket and shim belt driven DOHC, 94 bore x 67 stroke, 24deg valve angle - much oversquare cf. the RB series.   Two IHI RHB5 turbos, GFB electronic boost controller, hi-flow cats, engine internals standard.

My cams per factory have 8.6mm lift, 245Ex, 236In duration (at 0.5mm) set at 12-68-72-12 timing (as best I can find, no VCT).   Last year I reset valve clearances and timing when I installed new performance 'chips' (don't laugh! yes it still has the original un-flashable ECUs - yes two, for double the fun.....).  Thes chips are mapped to be good for 1.1bar/350hp supposedly.  Car runs Ok, slight leanness at low power/boost, boost comes on and it smooths out 4k and up.   Torque has moved up from ~3000-3500 before mod and probably revs better.   I don't have access to a dyno so no figures or data, just after info to make an 'educated guess' before I decide to change anything.

To that end, I was after the standard factory RB valve timing,  if anyone has it, to compare please?    I have a thick skin so pile on!  Some pics below.

TIA

 

64803548_876218939410524_4611679378407948288_o.jpg

Camshafts1.jpg

Link to comment
https://www.sau.com.au/forums/topic/479443-rb263-factory-valve-timing/
Share on other sites

https://www.tomeiusa.com/_2003web-catalogue/e090_camshaft-specs.html

 

 

 

To be honest I can't see how knowing a different engine, especially an inline VS vee engines cam specs will help, but above link has what you are after. No mention of at what lift, so please guess!

Yes, all info must be assessed, but engine config. probably less important than valve sizing and bore/stroke ratio I think.   That link looks like it has it all Ben, thanks!   Interesting, lift and duration are very similar to what I have, though the lobe centreline angle looks wider.   I also found Ferrari F40 data - same management system and vintage, not as overdsquare again - and it looks almost the same 244 deg duration and 12-52-54-10 timing.  More to chew one, thanks.

GhibliLow2.JPG

enginelow.JPG

  • Like 1

Keep in mind that both 25 and 25Neo have VCT which swings the cams ~20°. On the Neo, the cam profiles were changed from the vanilla 25 to further improve emissions and fuel consumption, as part of the whole ELEV thing that drove the Neo programme in the first place.

swap an LS....everyone's doing it!  or 2JZ?   Just teasing.

I'll stick with the V6 - probably the best bit of the car - smooth, compact and nicely engineered with Cosworth Coscast designed and manufactured heads.    Best value would be to install a modern single ECU and sensor set/loom, but I've invested/learned so much to get this far - old school monitoring software, changing the .bin with TunerPro and burning my own chips!

Chassis is very E30-like, gearbox is even a Getrag and currently has a 635CSi clutch plate in it.   And XR6 Turbo radiator and fan set,  stiffer King springs, rebuilt turbos and ceramic coating.

Does the VCT change only the inlet cam +/-20, or both?   I'm looking at the RB26DETT solid lifter data - no VCT on these?   Exhaust info looks funny, unless it gets moved 20.   Assuming the '113' and '120' figures are LCA.

IMG_20181021_151954.jpg

51 minutes ago, ALF750 said:

Does the VCT change only the inlet cam +/-20, or both?   I'm looking at the RB26DETT solid lifter data - no VCT on these?   Exhaust info looks funny, unless it gets moved 20.   Assuming the '113' and '120' figures are LCA.

VCT is inlet only on R33 onwards RBs (no RBs prior to that had VCT).

RB26 does not have VCT. There are aftermarket kits (HKS VCAM) to add it.

It's not +/-20°. Only 20° total. It's activated by throttle % and across an RPM band ending at about 4500-4700 depending on which engine.

Those figures are lobe centres, at rest.

OK thx.   Duration and lift are similar but RB cams are set with almost no overlap (using the stated LCA) whereas the Italian cars use 21-26 deg.   Obviously a different philosophy going on there?   Also, the valve clearances are odd to me - less on exhaust and more on intake (.38E cf. .45mmI) - pretty much the reverse of the Ghibli??  I think my exh valves are also sodium filled. Interesting.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • Hi...so a "development" here aswell The swap is "done" and car went "test drive" BUT it seems the clutch(maybe gearbox?) is a little bit sad? I bought this clutch kit https://justjap.com/products/xtreme-heavy-duty-organic-clutch-flywheel-kit-nissan-skyline-r31-r32-r33-push-type "Problem" is that the first gear is hard to put into and it seems that the clutch is not disengaged. It was not the problem with the old clutch...(or like sometime the first gear would not get as easy specialy when the fluid was cold) So? Can it be like...bad "install" or is the clutch wrong ((it should not have been) i done research to get the right one) Or is this "normal" with new clutch and needs to be break in? 
    • @Duncan I can try  and thanks i did not thought about VIN and part numbers for 33/34. @GTSBoy yeah it looks like iam gonna do that  
    • Forgot to include this but this is the mid section of my steering rack that looks like it has a thread/can be turned with that notch mentioned in the post:
    • Hey everyone, Wanted to pick some brains about this issue I'm having with rebuilding my 33 rack (PN is 49001-19U05). All of the tutorials/videos I've seen online are either R34 or S Chassis racks which seem to be pretty straightforward to disassemble but this process doesnt carry over to my rack. Few of the key differences that I've noted The pinion shaft on the other racks bolt on with 3 torx bolts: Whereas my rack bolts on with 2 allen head bolts: These changes are pretty inconsequential but the main difference is how you pull the actual rack out of the housing. The other skyline/s chassis racks can be taken out by tapping the rack out of the body with a socket and it just slides right out. I'm unable to do that with my rack because there's a hard stop at the end that doesn't let the seal/shaft be tapped out. Can also see a difference in the other end of the rack where mine has a notch that looks like you're able to use a big wrench to unthread 2 halves of the rack whereas the other racks are just kinda set in with a punch. My rack: Other racks: TLDR; Wanted to know if anyone has rebuilt this specific model of steering rack for the R33 and if there were any steps to getting it done easier or if I should just give this to a professional to get done. Sorry if this post is a bit messy, first one I've done.
    • I would just put EBC back on the "I would not use their stuff" pile and move on.
×
×
  • Create New...