Higher CR with Alusil's

[GBStu]

I’m currently in the middle of a rebuild (3.0SC) and found it has Alusil cylinders, having read the 400! posts on re-ringing them I think I’m going to take the chance. I would like to increase the compression of the motor (I have an 8.5:1 79 motor), I have read in Wayne’s book that you can offset bore the wrist pin to accomplish this (I’d rather do this than fly cut the heads).

Does anyone out there have any experience doing this?
And
Has anyone used JE pistons in used Alusil cylinders?

Any comments would be greatly appreciated

Thanks

Stu

[al lkosmal]

I have rebuilt a 2.7 w/Alusils, re-ringing etc. w/very good results. Rebuilt at 150K and I'm over 200K now and still going strong. However, I believe that the JE pistons are meant to be used w/ Nikasil only. Other more knowledgable plz chime in.

(I'm in the middle of rebuilding another 2.7 w/JE 9.5:1 pistons. I've sourced Nikasil cylinders to use w/these-- already sold off the alusils, but I'm still interested in the group think)

[Bobboloo]

As Al stated. JE's are to be used in Nikasil, Biral or iron cyliders. The pistons used in Alusil cylinders had a Ferrous coating. I suppose you might be able to ferricoat the JE's but it seems it would probably cost as much as nickasil coating the Alusils which seems to be a better solution.

[914timo]

...... it would probably cost as much as nickel coating the Alusils which seems to be a better solution.

Sorry Stu, I am now hijacking your thread, but I think we are in the same boat. I have ´79 3.0L SC engine too and I am currently thinking the same things as you do. I would like to have higher compression too.

So, is it really possible to re-coat old Alusil cylinders with nickel ?? Can I really "convert" my old Alusil cylinders to Nikasil cylinders and use J&E pistons with them ??

If this is so, this is really good day. This is a totally new alternative to me. I thought there is no way to re-use my old cylinders with some other pistons.

[kstylianos]

So, is it really possible to re-coat old Alusil cylinders with nickel ?? Can I really "convert" my old Alusil cylinders to Nikasil cylinders and use J&E pistons with them ??

Yes and Yes.

EBS can replate the your Alucils to Nikasil for about $150 per cylinder. They will work fine with JE's.

Depending where you purchase your JE's, I would send them with your cylinders to EBS so they can set up the proper cylinder clearances.

[Tim Hancock]

I just reringed my 79 sc w/alusils. Ihad about .010" fly-cut from the heads and went with a mild performance cam grind by Elgin. Check your valve clearance if you do the same it can be close.

I think I have a problem, I am approaching 1000 miles and my oil level has remained the same. I thought Re-ringing alusils was bad JU-JU because there is a good chance that one might burn more than 1 qt of oil per 1000 miles. I have not even used 1 qt in my first 1000 miles. Maybe my oil pump is not working HA HA! (sure as anything, when I drive home from work today the Porsche gods will get even with me for gloating on this!)

[GBStu]

Tim,

Thanks for the reply.....that is exactly what I want to do.

How did you "condition" your cylinders before the re-ring, also, what cam profile did you choose?

Thanks

Stu

[Tim Hancock]

I chose the Sport SC offered by Elgin my cams had some mild corrosion pitting on some of the lobes so I figured that I might as well upgrade a little by trying the Sport SC grind. I do not have the cam overlap specs in front of me right now but when doing the valve clearance check per Wayne's book, I ended up retarding the cams slightly to ensure adequate clearance for the intake valves. The exhaust valves were not an issue with this setup. John at Elgin said that this was no big deal (I think ended up at 1.6 as opposed to the 1.7-1.9 recommended initially by Elgin (dont quote me on these numbers).

I measured my cylinders and they measured about in the middle of the wornout/new specs. I just cleaned them in solvent and rubbed the walls with a scotchbrite pad by hand.

I ran the engine at 2K for 20 minutes initially per Wayne's book then changed the oil and filter (hardly any metal flakes). I then ran the next 100 miles on and off the gas alot to 5k rpm and after about 500 miles I started driving it pretty hard occasionly.

I actually expected to use some oil initially and I was prepared to live with an occasional puff of smoke. So far no oil leaks either! I may have just gotten lucky but so far so good!

Good luck with yours!

[1fastredsc]

Originally posted by kstylianos
EBS can replate the your Alucils to Nikasil for about $150 per cylinder. They will work fine with JE's.

Son of a b****! Oh well, at least the ausils are doing good so far.

Originally posted by Tim Hancock
I just reringed my 79 sc w/alusils. Ihad about .010" fly-cut from the heads and went with a mild performance cam grind by Elgin. Check your valve clearance if you do the same it can be close.

I think I have a problem, I am approaching 1000 miles and my oil level has remained the same. I thought Re-ringing alusils was bad JU-JU because there is a good chance that one might burn more than 1 qt of oil per 1000 miles. I have not even used 1 qt in my first 1000 miles. Maybe my oil pump is not working HA HA! (sure as anything, when I drive home from work today the Porsche gods will get even with me for gloating on this!)

Ditto, not one drop of consumption.

[TonyG]

I re-ringed my 105k '82 SC engine with K&S pistons and Alucils... zero oil consumption.

TonyG