Another 3.0 Rebuild

[Carrerax]

Originally Posted by brads911sc

Thanks Lindy.

That is the plan so far.

I have a call into Steve W and EBS on the replating.. and cant see the extra 2k now on Nickies since its a street car and there doesnt appear to be any damage to the cylinders. They all look brand new..

Make sure to discuss aftermarket pistons with Steve prior to buying any. I ended up buying good used RSR Mahles instead of the JE/Weisco's. Im just sayin...

[lindy 911]

I had the main and rod bearings coated. You need to pay attention to the over-spray on the back side of the bearings, lightly sand it off if there is any with 400 grit emery cloth. This is the surface that mates with the case and the sanding marks on the bearing allow it to grab the case a little better.

Lindy

[brads911sc]

Which coating of theirs did you use? Was it the "Dry-Film Lubricant Coating"?

Thanks

Originally Posted by lindy 911

I had the main and rod bearings coated. You need to pay attention to the over-spray on the back side of the bearings, lightly sand it off if there is any with 400 grit emery cloth. This is the surface that mates with the case and the sanding marks on the bearing allow it to grab the case a little better.

Lindy

[tadd]

Brad:
Don't discount twin plugging. It about $400 to add the second plug hole while the heads are out. Get it done, add the second plug and just put the lower valve covers on. Then its there when you can afford to add the ignition, be it coil packs or distributor.

Twin plug makes the motor far more resistant to detonation regardless of compression. Its cheap insurance and you could easily run midgrade in the cooler months to make up the cost.

FWIW, more compression is better effiency and it is also one of the major drivers in cam choice. Run around 9.5-10:1 and alot more cam choices become avaiable.

A personal, devils note on cams... most folks will tell you to way under cam. IMHO if your doing port work anything less than a 'modern S' is silly. Take a serious look at a DC 44 on 102 LC. See Cam Arnotts 2.3 thread. I guess my point is don't cheat yourself with some E cam.

If your truly on a tight budget, take a hard look at head work vs beefing the bottom end (R&P rods, center drill crank). I've also been told that the big port SC heads are really, really good out of the box from porsche. To this point there are some big port (stock 40 mm ports) 2.8 SS on pelican running RSR sprints that have been described as magic on the street.

As full disclosure, Steve did my heads for a 'just this side of race' early Al case 2.8 and they are purdy sitting on the bench top... 47.5 mm intakes and all. I'ts 'only' another $1500 or so for CNC porting, so why not do both . I did . Come on over to the empty wallet side... .

tadd

[lindy 911]

That is correct. The piston crowns were done with the heat shield coating and it works.

Lindy

[brads911sc]

John (camgringer) recomended a GT2 profile on a 108 lobe center. Not as wild as the DC40-108, and not as peaky as the DC30.. so that is settled.

Found a set us used Matched Rods from a fellow Pelican. Thanks Tom (tom1394Racing)!

Havent talked to Steve W yet on P&C's. Left him a VM and email. Mondays are always busy days. So far after talking to Don at EBS.. Ill send my current KS Cylinders for replating (Millenium Plating) and a set of 9.5:1 JE's... Unless Steve W Talks me into a different approach.

Thanks All. Plan coming together.

[brads911sc]

Spoke to Steve W on a variety of topics. What a wealth of information.

He wasnt thrilled with my "cheap" P&C solution. I need to balance cost vs longevity with his recommendation -- Stock Mahle 9.3:1 (3800) or MM Set (4700) that will last forever with Replated KS/JE (2000) which will last 50k miles and wont have the tight clearances (read increased oil use and noise)... the Mahle's are double the price. HMMM

I do have a budget.

He also had alot of ideas on Cams (GT2 profile vs 964), Rods (pauter vs rebuilt stock), Rod bearings, Gasket kits.. Damn... if money were no object... I need to balance the price tag against not wanting to re-do this in 5 years.

[joetiii]

Not sure if this has been considered so how about having current pistons machined to clear the valves. It's certainly not the best piston design but if you're not going to make this a race engine, how much will the new pistons add in performance if you stay at 9.3:1?

[brads911sc]

According to Steve the issue is that the wear points on the KS Alusil piston (top ring grove and skirt) makes this virtually impossible. If these were Nikasil Mahle then it wouldnt be an issue. So its new Nikasil Mahle in stock form (3800) vs replating the KS Alusil with Nikasil and JE's for 2k. The Mahle's are obviously probably better suited for a street car... but the price.. wow...

Thoughts?

Originally Posted by joetiii

Not sure if this has been considered so how about having current pistons machined to clear the valves. It's certainly not the best piston design but if you're not going to make this a race engine, how much will the new pistons add in performance if you stay at 9.3:1?

[mca]

Really? The longevity of JEs is only 50k?

[HarryD]

Try the want ads:

FS: 3.0SC Mahle Pistons 9.3CR

For sale high compression 3.0sc 204bhp pistons/cylinders

FS 84-86 911 pistons &cyls

FS US spec SC pistons and cylinders

[mca]

If the lifespan is that short for JEs, I'd go for a more durable package.

I have over 10k on my rebuild with JEs and it still feels like I was putting that thing back together yesterday - it was 2 years ago. Can't imagine opening it back up in roughly 3 years.

[brads911sc]

I was told by two builders that we all consider expert that they will last 50-60k miles. If I am looking for a 100k solution, Mahle is the only solution...

Maybe I should try to source a set of Used Nikasil Mahle's as Harry suggests...

Originally Posted by mca

If the lifespan is that short for JEs, I'd go for a more durable package.

I have over 10k on my rebuild with JEs and it still feels like I was putting that thing back together yesterday - it was 2 years ago. Can't imagine opening it back up in roughly 3 years.

[5String43]

Ah-hah! How to discover that water does not compress! Shame. Good luck with your rebuild.

[brads911sc]

Will I have clearance issues with the GT2 108 with stock Mahle 9.3:1 pistons?

Originally Posted by joetiii

Not sure if this has been considered so how about having current pistons machined to clear the valves. It's certainly not the best piston design but if you're not going to make this a race engine, how much will the new pistons add in performance if you stay at 9.3:1?

[lindy 911]

I don't want to sound disrespectful but the new JE pistons are awesome. They have not been around long enough for anyone to put 50,000 miles on them so that point is mute. I have many, many favorable experiences with JE in other applications, some of which over stress the design much further than even the most radical NA flat six. Steve knows his stuff, that's for sure, but I don't think he's considering the new design JE.

Lindy

[joetiii]

I would check out that last link to used P&C's. If clearing the DC40 cam is a problem, you can opt for camgrinder to grind you the DC24 which is one step down from DC40 but with a 113 LSA.

[brads911sc]

Update. Spoke to John (camgrinder). My GT2-108 are already being worked on. Paid for.

he wants 9.5:1 or 9.8:1 compression to get max torque to come on sooner and have the most power at 2500-6000 RPM's... The stock Mahle's are going to impact performance in his opinion.

he also said that stock Mahle's will need to have the pockets cut to use them. This would lower compression further... I dont want to get into all that...

So Im back to Replated KS with JE's. If they last 60k miles, that is 12 years at my current mileage. Hopefully you are right Lindy. Time will tell.

Thanks all for your support and opinions.

[Carrerax]

Originally Posted by lindy 911

I don't want to sound disrespectful but the new JE pistons are awesome. They have not been around long enough for anyone to put 50,000 miles on them so that point is mute. I have many, many favorable experiences with JE in other applications, some of which over stress the design much further than even the most radical NA flat six. Steve knows his stuff, that's for sure, but I don't think he's considering the new design JE.

Lindy

Steve W knows about the new design ones. I also discussed many options and went with Mahles when using Mahle cylinders. With nickies etc I may have gone the JE route. Many opinions on this and when I decided that I want this engine to last a long long time my decision was easy. That said, I also know another very good engine builder that wanted me to use JE's. Different strokes for different folks etc.

[brads911sc]

Its really a mute point because the camgrinder (john daugherty - who is one of the industry best) recommended a GT2-108 cam that will not work with the Mahle's unless the pockets are cut, impacting their price and static compression... JE's will work without any modifications and have higher static compression (9.3:1 vs 9.5:1).

so now I have 3 choices. I am working with Don at EBS.
1. Replate my KS Cylinders (Millenium Plating) and keep at 95 mm. 9.5:1.
2. Replate a set of 3.2 Cylinders and increase to 98 mm. 9.5:1 3.2 SS. This will be more $$ because I dont have 3.2 cores.
3. Wait a few extra months to save some extra money and go with Nickies. probably do 98 mm 3.2 SS if I went this route.

Plating with #1 or #2 is lifetime warranty... and half the price of #3.

What I cant really get an answer on is whether there is any value add to spending 2k more on the Nickies. Its a street car. Rev limited at 6500 rpms. Never goes past 8'oclock on the temp guage.. So unless its just to look nice, doubt they are worth the extra money for my car. So It will probably be opt 1 or 2 for me unless someone can tell me why i would want to spend the extra money.

While I appreciate and respect Steve W 's feedback... he is a great guy and a wealth of knowledge... his recommendations would 1. not allow me to use the Cam that John recommended without major piston modifications and 2. would lead me to a rebuild that costs more than the car is worth.. I did use him for the head work so they are matched to my ITB's for optimal flow and performance. I am sure all his work is second to none. For the rest of my build plans, I need to 1. balance his very expensive recommendations against my max budget (about 10k), and 2. find a non-stock Mahle PC solution that will work with my cam choice. Those are the parameters I need to live within.

Originally Posted by Carrerax

Steve W knows about the new design ones. I also discussed many options and went with Mahles when using Mahle cylinders. With nickies etc I may have gone the JE route. Many opinions on this and when I decided that I want this engine to last a long long time my decision was easy. That said, I also know another very good engine builder that wanted me to use JE's. Different strokes for different folks etc.