Will stock fuel head/pumps/injectors handle this

[flightlead404]

I am considering the following mods to my 930. It's currently pretty stock except for no cat, "free flow" B&B exhaust, and a K26.

-K27 HFS or 27/29 or similar
-Bigger long neck intercooler
-Equal length/tuned headers
-SC Cams

It's looking like I need a new clutch also, so probably a lightweight clutch package.

Will the current fuel system handle these, or will I need fuel head work and/or bigger injectors?

Is it recommended to rebush and recondition old rockers? or replace?

Should I plan on new valve springs, keepers etc? Do I need to shim the springs to a different hight?

Before I start I will do a compression and leakdown and probably borescope the jugs to get some understanding of the health of the top end. If I'm OK I will leave it there, with all the Dilavar studs and everything. If it appears I need any cylinder/head work at all, I will bit the bullet and pull all the jugs, and do the Mahle 3.4L 7.5:1 P's and C's with ARP studs, new seats and guides and so on.

At that point, will I need any fuel system upgrades?

Thanks!

[mark houghton]

Stock CIS will handle your mods. If you start pushing beyond 400hp, many say that that's close to the limit of CIS fueling, though others have claimed to run yet higher hp and get away with it. You didn't mention what boost you were planning, though. I would suggest an adjustable WUR to fine tune your mods in order to assure sufficient fuel when at full tilt boogie, especially if you plan to increase the boost.

[RarlyL8]

Depends on what fuel distributor and WUR you have. If USA, no, if Euro, yes, but you will need to make the WUR adjustable to optimize the fuel curve.

[JFairman]

If the Mahle 3.4 set is an option just do it.

[flightlead404]

Originally Posted by mark houghton

Stock CIS will handle your mods. If you start pushing beyond 400hp, many say that that's close to the limit of CIS fueling, though others have claimed to run yet higher hp and get away with it. You didn't mention what boost you were planning, though. I would suggest an adjustable WUR to fine tune your mods in order to assure sufficient fuel when at full tilt boogie, especially if you plan to increase the boost.

I meant to include an adjustable WUR on the list, as well as an AFR/boot gauge.

I was planning on somewhere between .8 and 1.0 bar. Need to check the effective CR chart and decide where on that curve I can comfortably live

[flightlead404]

Originally Posted by JFairman

If the Mahle 3.4 set is an option just do it.

Its $5k more plus significantly more work. The other stuff is basically bolt on.

What is the list of recommended "while you are in there" or other replacements?

-Tensioners
-Tensioner oil lines
-Chain ramps
-New timing chains?
-Other?

[Jeff NJ]

Originally Posted by flightlead404

Its $5k more plus significantly more work. The other stuff is basically bolt on.

What is the list of recommended "while you are in there" or other replacements?

-Tensioners
-Tensioner oil lines
-Chain ramps
-New timing chains?
-Other?

Not sure of the mileage or year of your 930, but I pulled my motor last winter and did much of what you are considering, except I kept the stock cams (for now). k27hfs, headers and exhaust from Rarlyl8, adj. Leask WUR, Turbokraft halfbay IC, Sachs LW clutch PP.

I looked over the things you listed above and mine all looked impeccable, so I left them.

Suggestions for while you're in there:
fuel lines if they are original.
Lots of gaskets and seals that are prone to leaking, especially in the triangle of death.
Injector blocks from Turbokraft if yours are original.
TiAL wastegate
Engine/trans mounts
turbo drip can - the stock one didn't work with the rarlyl8 headers.

I also did a suspension refresh - all new bushings, tie rod ends, ball joints, shocks and struts rebuilt by Bilstein, etc., but that doesn't need the engine out, so it can wait.

My build thread is linked below and there are a bunch more that I referred to when working on mine. Highly recommend reading them prior to starting to get ideas, tips, and then bookmark them for easy access when you run into trouble.

Time to upgrade Jeff NJ's 930

Take a LOT of pics while taking everything apart, and start an engine drop thread!

Good luck!

[Alan L]

I ran out of fuel with the US head with the specs listed below. Not grossly out of fuel - but at the top end 5600-6000rpm, not enough. At a guess you are close with a US head. May work, may not. You may just squeek in. Worth trying first. The head is easy to change over when everything else done and you know what you need - ie how short of fuel you are.
Regards
Alan

[flightlead404]

Originally Posted by Jeff NJ

Not sure of the mileage or year of your 930, but I pulled my motor last winter and did much of what you are considering, except I kept the stock cams (for now). k27hfs, headers and exhaust from Rarlyl8, adj. Leask WUR, Turbokraft halfbay IC, Sachs LW clutch PP.

I looked over the things you listed above and mine all looked impeccable, so I left them.

Suggestions for while you're in there:
fuel lines if they are original.
Lots of gaskets and seals that are prone to leaking, especially in the triangle of death.
Injector blocks from Turbokraft if yours are original.
TiAL wastegate
Engine/trans mounts
turbo drip can - the stock one didn't work with the rarlyl8 headers.

I also did a suspension refresh - all new bushings, tie rod ends, ball joints, shocks and struts rebuilt by Bilstein, etc., but that doesn't need the engine out, so it can wait.

My build thread is linked below and there are a bunch more that I referred to when working on mine. Highly recommend reading them prior to starting to get ideas, tips, and then bookmark them for easy access when you run into trouble.

Time to upgrade Jeff NJ's 930

Take a LOT of pics while taking everything apart, and start an engine drop thread!

Good luck!

Thanks Jeff. I'm doing an oil cooler upgrade and a soup to nuts a/c replacement too. All suspension done already, will do the motor mounts, engine bay seals, wg replacement too. Thanks for the tip on the drip can. I did a ton of seals including ToD a few months ago with the engine in the car. It will be my first engine out on a turbo, but had the engine in and out of my SC many times, and did a motor rebuild myself on that too. Was the first engine I ever rebuilt, 20 years ago :-)

[porche]

I believe the 1978 and 1979 NA (USA/Canada) 930 Fuel Head Assembly (Fuel Dist./Mass AF Meter) is the same as the European units through 1989.

[Alan L]

You won't find this too much different to the SC once you get past all the turbo reticulation system . The upstairs plumbing is different but below that the short block is pretty much same.
Alan

[Tonger]

Advice from Jeff NJ is spot on. The rebuild items that I am happiest about are the Sachs lightweight clutch from TK with light pedal effort and great response, WEVO 930 shifter and coupler, Leask WUR (would have saved me a ton of time if I had started with this), and TK alloy injector blocks - because even though they don't look cracked, they're cracked. For tuning a good wideband AFR meter with data capture is a good idea (I use a WEGO IV) and a Leask RPM kit should be on the list too. I tried to tune without the rpm kit and it was again just wasted time.

If you need more fuel, you can get your fuel head modified at CIS Flowtech. Larry Fletcher is a great guy. If that's not enough, I changed to the larger euro fuel lines and injectors. Now I've got plenty.

Good luck and have fun!

[flightlead404]

What is the Leask RPM kit? What does it do?

I had thought about a MSD programmable unit, but I'd prefer to keep complexity low as possible.

[JFairman]

It's an RPM switch and Pierburg vacuum solenoid kit that blocks boost pressure from reaching the boost enrichment port on the bottom of the control pressure regulator until the set RPM.
It reduces the over rich AFR's during boost below 5000 rpm or wherever you set it.
FWIW, the summit racing digital RPM switch is half the price of the obsolete tech MSD analog rpm switch and it's "pills", and you can buy Pierburg vacuum change over solenoid valves used on the 996 (that work the same as the old ones used in a 930) from Pelican or with a google search.

[Tonger]

Fairman is correct about the Summit switch. The Leask kit uses an MSD pill box that is decidedly more retro looking. I made a harness for mine, put it on an aluminum bracket, and put a 'vorsicht' sticker on it.

You didn't ask about turbos and headers but I have the Garrett GT35r twin scroll turbo and twin scroll headers/exhaust with short primaries and twin WG from TK and could not be happier. Car spools early and often. I know people debate the equal length vs. short primary question a lot, but there's a full bar of boost by 3200 rpm or so.

[flightlead404]

Oh somebody asked earlier in the thread what I have, its an '86 no sunroof coupe, LSD, lots of suspension upgrades, welmeister short shift, pushing 80k on the clock.

[RarlyL8]

The stock '86 CIS will be on the edge with the mods you have listed, assuming the long block is left stock with the only change being SC cams. If you go with bigger cams or do any head work the fuel system will require modification. The AFR meter will tell you how much.

There may be a misconception on the strengths of tuned headers. They will not spool noticeably quicker than short tube headers but will add torque off-boost and add power on boost. The sound also is completely different. A stock 3.3T engine with K27-7200 turbo, RL8 muffler and SC cams will hit 1.0bar before 3000rpm. My personal car was on full boost at 2800rpm with that combo and would tear the tires loose when it hit.

[JFairman]

New original vintage Pierburg vacuum changeover valves that came in 930's and old Mercedes.
Google: Pierburg 0015407097 for lots of them including questionable used ones.

Best price I found on a new one... Mercedes A 0015407097 Vacuum Valve

...you won't find these on pelican.

[flightlead404]

I was planning on 1 bar WG if I don't change the P's and C's, and .8 bar WG if I go with the 3.4 7.5:1 setup.

Reasonable?

[930/66]

i run 1.05 bar boost with the original p/c (7.0:1), with the 3.4l (7.5:1) 0.9 bar
Euro fuelhead modified with blwur and rpm switch