Rebuilding a 3.0l SC as a turbo
 

I’m looking for advice on a few 10,000-foot decisions with my 3.0l SC turbo rebuild. I’m not looking to find a core from a 3.2 or 930. I think the hp goals should be reasonable for my 3.0SC core.

Goal: <=450 WHP. Be able to run full power on the street but be able to turn the power down below 400 for track days. I only do about 3 or 4 per year.

I currently have:
• 3.2 Carrera Manifold
• Garrett GT030R Turbo
• Megasquirt II

Planned changes:

P&C:
• Mahle 98mm 7.5:1 P&C set – ($4500)

Rods:
• Carrillo Rods

Cams:
• Regrind SC cams to 964 profile

Heads:
• Upgrade valve springs, retainers, and guides.
• Twin plug
• Port match (within reason) to the Carrera manifold.

Additional planned updates:
• 964 Oil Pump.
• Upgrade case oil squirters
• ARP head studs.
• Refurbish the crank (machine out the oil plugs to truly clean it.)
• Upgrade intercooler
• MS3 Pro for full ignition control.
• Add knock control (I think MS3 can only handle 1 knock sensor input)
• 930 4-speed w/ LSD (Stock gearing, planning to drop 3rd and 4th down for better drivability on track)


Kyle

Smart, and should allow you to easily achieve your goals.

Mahle P&Cs should get you where you want to be, as will the cams.

Stock rods aren't light, but they're plenty strong, especially rebuilt with ARP hardware.

Camgrinder can grind your SC cams to 993SS for a really affordable cost and I believe the stock valve springs and hardware can stay 100% stock. 3.0 rods use larger rod bolts than the 3.2 like I have, so I wouldn’t see a problem using stock rods (after resizing big end and rebush little ends) using ARP bolts.

Thanks for the 'reinforcement' replies.

I think I'll go with the turbo Mahle 3.2l P&C's and possibly Carrillo rods if I decide. I still have time...

Will be pulling the motor in a few weeks to send to a local builder. I'm trying to get a few of the big $$ parts ordered ahead of time.

Hey Kyle, interested to hear how it goes. Keep us posted.

following!

Ordering parts
 

I'm beginning to order parts.

Question for the engine building guru's:

I'm ordering a set of Carrillo rods. They have an 'upgrade' option to get CARR bolts which are good for 8500rpm. Is this legit or should I go with ARP's?


CP-Carrillo Connecting Rods Set for Porsche 3.0 Liter with 3/8 CARR Bolts
$2,479.08In stockSKU: PR-3.0>-65030S

CP-Carrillo connecting rods are fully machined from a proprietary 4330m alloy forging for strength and durability. Rods are available with 2 types of bolts: The standard WMC-H7 (H11) bolt with a UTS of 220ksi and our upgraded CARR-S7 (MP35N) bolt with a UTS of 285ksi. The CARR upgraded bolt is a good choice if planning on revving the engine higher than 8500rpm. All our bolts are manufactured with asymmetrical threads, each thread has a slightly different design than the previous giving the bolts an evenly distributed thread engagement. This helps increasing the clamp load and fatigue life of the fastener.

ARP has a very long reputation of being pretty good.

Over the years, we've sent in several sets of Carrillo rods for inspection and testing, rods that came out of engines we did not build. Bolts are tested for stretch to see if they've gone "plastic," i.e. permanently deform when torqued to value. Every set of rods with WMC bolts ended up getting new bolts, while only twice have we had to replace CARR bolts -- and those two engines were sorely abused.

Here's what Carrillo told us decades ago:

WMC bolts are adequate for most applications, and can be torqued approx. 2-3x before you have to replace replace them. It is essential to keep a log of the pre-torque length and measure every time.

CARR bolts are the best, and can be reused over and over -- if they have not been stretched from over-torque or over-rev.

We always measure both stretch and torque, and not once have we had a CARR bolt deviate from the published target torque value in order to achieve proper stretch.

We only specify CARR bolts.
a) buying them 1x costs less than buying WMC bolts twice
b) like good valve springs, they seem like inexpensive insurance in the event of an over-rev
When failure usually results in catastrophe, it doesn't seem like a wise place to save money.

Chances are your valvetrain will give up before 8500rpm and the real benefit for CARR bolts is the fact that they can be reused multiple times. If that is not a necessity for you, then you might as well spend your money on other things and go with the regular ARP bolts (which are very good quality). With stock SC cams, your peak hp will probably be in the 6200-6500rpm range anyways.

Thanks Chris! That's the explanation I was looking for!

Moving forward.

P&C's (10-week delay), rods, rod bearings, on order.

http://forums.pelicanparts.com/uploa...1701711240.jpg

Would recommend to change oil squirters from 0.8mm to 1.2mm and turbo oil pump.
That what RUF did on the basic 3.2.
You need to cool down the piston more on a turbo engine.

This is some don't think of but its very important

http://forums.pelicanparts.com/uploa...1702123448.jpg

http://forums.pelicanparts.com/uploa...1702123448.jpg

http://forums.pelicanparts.com/uploa...1702123592.jpg

Yes, that's part of the plan. The motor is apart now.

This was the issue: (#4 piston) The cylinder wall had light scoring but otherwise ok. I didn't find any glitter in the oil or anything on the magnetic drain plug. ??

http://forums.pelicanparts.com/uploa...1702314509.jpg

UPS says the Mahle P&C kit is showing up today. Only two weeks, not ten!

Sweeet

Have you try changing oil squirters from 0.8mm to 1.2mm and turbo oil pump

Any updates to your build?

Quick Update
 

It's moving forward. Crank is out getting machined but should be back this week. Sent the cams to Dougherty to regrind the SC to a 964 profile. Rockers were sent along with them to get refurbed. The cams came back last week.

Once the crank is back we should be able to start assembling the case.

Heads and Carrera intake was lightly ported. Otherwise, the heads are still on hold as we line someone up to do the twin plugging. Then on to fire-ringing then off to new valves, springs, retainers.

I'll be stopping by the shop this Thursday to check in.


http://forums.pelicanparts.com/uploa...1710904508.jpg



http://forums.pelicanparts.com/uploa...1710904508.jpg

Did you elect to go with the 7.5:1 compression?

I'm mentally gearing up to rebuild my SC turbo conversion.. currently using 9.5:1 Max Moritz style in 97mm turbo barrels.. I wont be changing the gearbox so the 915 will be the limiter.

If I twin plug my heads and use a 964 cam (slightly more overlap), do you think I can still use the 9.5:1 compression ? I like the car to be quite drivable off boost, and am worried that much less than 9:1 would make it feel pretty sluggish?

I did. 7.5. The stock compression was 8.5 and did well at around 10psi, until it didn't. I beat on it pretty good for about 8 years.

I know 9.5 compresson has been done, but you'll need to be careful with timing and boost. At that level, knock sensor(s) control or at least monitoring would be advised along with twin plugging for added safety. Boost will add to your compression ratio dynamically. With 10 psi, your dynamic CR could be above 13 compression. I'm no expert though, I'm sure others will chime in with better advice.

I need to check into the shop this week to see if there's been any progress on the lower end and find out where we stand on the heads. (Who's twin plugging, fire-ringing...etc.) Otherwise, nothing new to note so far.

Thanks for replying... that's interesting about the 8.5:1... were they the stock cast Mahle pistons? If so, the 8.5 that Porsche claims is usually closer to 8:1...which makes me think the 9.5 is not a 'great' idea at all, even with twin plugging.

Yes, I'm pretty sure they were stock cast.

You can calculate dynamic compression here:

https://www.rbracing-rsr.com/comprAdvHD.htm I believe the 964 cam inlet closes @ 72° ABDC. I might have exaggerated the dynamic compression calculation, but you can try it yourself.

930 3.3 Heads?
 

So the project is lightly being held up finding someone to do twin-plugging on my 3.0l heads.

Question: I found these 3.3 930 turbo heads on eBay that have been rebuilt and twin plugged already. Would they work on my 3.0l motor?


Porsche 911 turbo Carrera 3.0 Cylinder Heads twin plug Fully Refurbished 930 3.3


https://www.ebay.com/itm/124530804835?itmmeta=01HV2BN4JNFNBDNBCZSB9SEHTS&ha sh=item1cfe9d4863:g:4NEAAOSwV~NgAxDM

Those ebay heads look excellent. Wish we had stuff like that for sale over here.!

Have you tried to contact Craig Garrett to do your heads?

Craig Garrett? Ohh...CGARR here on the forums... I haven't. I'll look him up.

Slow Progress - But moving Fwd.
 

Progress has been slow. But we're creeping forward. Got the heads back from Craig. (They look fantastic!) I'll be upgrading the stock springs to the AASCO springs and retainers (Good to 8000k, for 'insurance') Rev limit will be set at 7k. The 964 cams run out of steam at 6500 anyway but it doesn't hurt to have a cushion.

http://forums.pelicanparts.com/uploa...1718928211.jpg


I still plan to to the Niresist Rings (flame rings).

http://forums.pelicanparts.com/uploa...1718928211.jpg

I have 98% of the parts in place. Once the heads are finally sorted and ready, it should be mostly assembly from here out.

Case was being sent out for proper cleaning and we should be able to get the bottom end started.

Hopefully just a few weeks out before things start happening.

Oh, I also decided on new 3rd and 4th gear ratios for the 930 4-speed.

I've already purchased and received thru Matt for 4th gear (Guard Transmission) and RetroSport for 3rd gear availability.

http://forums.pelicanparts.com/uploa...1718928434.jpg

It's been super slow progress. Heads and cylinders went out to get Fire Ringed, should be back from the machine shop soon. Shortly after getting them sent out, the bottom end began to go back together.

Then the first snag appeared: The bearings were outside the range by .004". (Loose) The option is to get the cases bored and back into spec. I need to check in with my builder this week if a shop was found to do the work.

Otherwise, we're technically on the downhill side of things with it going back together. Once, the motor starts to go back, the transmission re-gearing will follow shortly after.

Hopefully I'll have enough time to get it back in the car and running before the rain starts again in the PNW.

Wow we are pretty much on the same path.

I'm not alone!

Chris (Turbokraft) called me right after I posted this and said the fire ringing is done. So the heads and cylinders should be coming back soon for hopefully the last time.

With the EFI system, do I need the fuel acccumulator, or can it be removed?

I left mine on for laziness and also incase I needed to put my CIS motor back in...

However on other cars that I ran efi, I removed it and just run the filter.

Update
 

Turbokraft is sending the heads and cylinders back from getting 'flame ringed'. Also getting performance springs for the valves to give me a safety margin.

We also have a solution to the case clearance. We were going to send it to Competition Engineering, but opted to get the bearings coated (need .004") instead. Using Line 2.
https://www.line2linecoatings.com/

This was the last thing in the way for re-assembly of the engine.

Which EFI system did you end up choosing?

This is an interesting potential solution to your problem of excesssive main bearing clearance. Hoping you share the results. I'm a little skeptical but keen to learn.

I haven't completely decided on EFI. Currently leaning to upgrade to MS3PRO (Currently using MSII, fueling only)

I've been looking at Haltech Elite 2500 (or 750) Mainly because it has knock input available. The 750 doesn't. But I could go down the rabbit hole with you guys about needing are not needing knock control. I'm open to comments.

MS3 might be an easy transition and it's a bit cheaper, and has knock control available if I need it. I also know it pretty well as I've been using it for about 10 years on both the NA and Turbo version of my motor. Never had any issues.

Whatever I decide on, I'll eventually go full fuel and ignition control. I'll be adding a cam sensor and TPS to the mix.

I was just at the shop today and they have the bottom end going back together. We've run into another hopefully minor snag of the #8 bearing being too tight. They're verifying the part number. It's possible it's oversized but need to confirm.

Otherwise it's starting to go back together.




http://forums.pelicanparts.com/uploa...1729033233.jpg

http://forums.pelicanparts.com/uploa...1729033345.jpg

I have MS3 and love it. Want to go to COP eventually but will stay with EDIS for now until I have issues.

I believe Haltech have just released a newer version the nexus which has onboard wideband now.. (finally).
You're this far in, may as well fit a knock sensor (or two). I would imagine it's even more necessary on a turbo engine?

I would agree with Mike. Having the knock sensor gives peace of mind and may allow you to tune a little more aggressively while protecting your engine. I did it on my EFI conversion and don’t regret it for a minute.

I have been looking at the ECU Master Classic which does have knock control capability and on board wideband input, plus the usual goodies. It seems to be a good value.

https://ecumasterusa.com/products/ecumaster-emu-classic?utm_campaign=gs-2020-03-04&utm_source=google&utm_medium=smart_campaign&tw_ source=google&tw_adid=&tw_campaign=18314156523&gad _source=1&gclid=Cj0KCQjwyL24BhCtARIsALo0fSDPrLHue8 lgQD6QKmkXbVSjdX-69xVDJ48ZzaJSE_90Jf9vWrLueAoaAuBREALw_wcB&variant= 8318139531325

What method are you contemplating to obtain your cam reference signal?

I'm all for knock control. You don't need knock control - until you're glad you had it. Like insurance.

If it protects against fouled plug, bad injector/tank of gas, operator confusion or EFI misconfiguration, could pay for itself pretty quickly.