The block is out, and all the internals.
A SCAT 9000 cranks is going in.
TRW fordge pistons. Stock rods with arp bolts.
The block is going to be +0.30.
All rebalanced.
What pistons rings do you recomend to use with those pistons?

I also heard that a too smooth of a hone job is not good at all, you need exactly the correct surface finish/pattern to seat rings? So is this something my engine build should know? Any tpis there?
And what about piston to wall clearence?

And is there anything I can do to the block while I have it out, that you recomend?

Thanks





[Modified by devilfish, 5:16 PM 5/23/2004]

 

Plasma-moly rings are the common ring these days. They resist the effects of detonation a bit more than moly or cast iron rings.The finish on the cyl should be determined by the ring manufacturer.Most coated rings need a smooth cylinder finish.Ring manufactures/machanist knows best. Piston to wall clearance should be set based on piston manufacturer. They will give a range of clearances. You and your machinest will have to decide what is best. Nitrous, blown or turbo motors will need more clearance than n/a motors. Ring end gap has to be set the same way. On both end gap (rings) and piston to wall clearance to error on the large side is safer than too tight. Hope this helps.

 

Thanks.

So where can I get info like Piston to wall clearance ? In this case I will use TRW fordge pistons. So I have to call TRW then?
Im looking at total seal Conventional Classic Race Ring Sets. They come in standard pre-fit end gaps. So I cant adjust Ring end gap.

 

I only use and recommend Speed Pro single plasma moly rings, .005 oversize for file-fit. I use only their SS50U standard tension oil ring set.

The machine shop should know what finish to put on the cylinder walls for moly rings. Moly rings call for a smooth wall (but not mirror smooth), since a rougher finish can chip the moly. The finish and cross-hatch should be left to the guys who do this for a living and know their stuff. The ring maker's recommendation for wall finish should be followed.

Choose a machine shop that regularly does racing engines. Their equipment will be more precisely calibrated and their reputation depends on the quality of their work. They won't continue to get much business if the engines they machine lay down in power production department or fail frequently- racers talk.

Take a walk through the machine shop a check they they have the latest equipment. Check for the neatness/cleanliness of the shop; how well organized things are, etc.

Ask about getting a complete listing of the specs/clearances including the bobweight chart from the balancing.

Make sure they line hone the mains since you're going with a different crankshaft. Have the ring set and bearings BEFORE the balancing in done so those weights can be factored in.

Make sure all the oil gallery plugs are removed before the block is cleaned. Be sure they replaced the plug under the rear main cap before you assemble the engine.

You could grind and smooth the lifter valley to improve oil return to the sump.

Jake

 

I used Speed Pro rings and filed them to size per piston manufacturers recommendations. Working very well, no problems or oil consumption. I honed my cylinders myself. Nothing fancy.

 

Thanks do much for the tips.

Do I need to align hone the mains with my new crank, I heard otherwise?
I cant get the oil gallery plugs off. They sit to tight. I jyst have to ask the machine shop to do that.
About the plug under the rear main cap, I cant found that?? I just got "holes", no cap. Mayby im looking at the wrong place??

I tried to mail TRW ( speed-pro ) about piston to wall clearance, but no answer yet :(
So you wount recomend standard gap rings?





[Modified by devilfish, 10:53 AM 5/24/2004]

 

tt

 

Piston to wall should be in the area of .0045/.006 (+/-) for forged pistons, but that's just a ballpark range. You need to know the SPECIFIC recommendation for the pistons you're running. The correct piston to wall clearance depends on the expansion characteristics of the piston, their skirts, the intended RPM range of the engine and expected engine temps, etc. The pistons should come with a spec sheet showing the recommeneded PTW.

.005 over-size rings (file-fit) are the best way to go. Each one should be individually gapped for it's specific bore. There have been several posts and horror stories about rings similiar to the ones you listed as being considered.

If I remember correctly, there was a recent post where a Forum member has gone through two sets trying to get them to seat. All I can advised is - DON'T.

The plug you can't find is in the block, not the rear main cap.

Jake

 

Jake is the man! I'm on my second set of Total Seal rings and they are still letting oil by. Installed them exactly as specified, 280 grit hone and lube with WD-40. Went against all my years experience but that is what Total Seal recommends.

 

Im learning here! ;)

:cheers:

Ok I will check with TRW once again.
The ring end gap should also be something TRW should know right?

 

But If I measure the mains and the crank and all checks up, must I still align hone the mains??

 

Measuring won't do it. All five must be correctly aligned. All measuring will do is give you the bearing clearances, not whether the main saddles are straight or even if the crank is straight.

There's an "El cheapo" method: verify the bearing clearances are correct and spin the crank by hand. If there are no tight spots or even the slightest binding, it's good to go. I DO NOT TRUST THAT METHOD.

There's also a method of using a mandrel of the correct diameter and length. Install it and torque the main caps to spec and spin the mandrel. Check for tight spots and/or slight binding. Most shops won't have the correct mandrel though.

If you experience drag or tight spots, it could be the block or it could be the crank itself. A dial indicator is then used to verify the straightness of the crank at all five journals.

This is work best left to a competent machine shop that has experience in performance engines.

Whenever you change cranks the line hone should be checked. Don't let anyone try to convince you otherwise. Are they going to pay to pull and rebuild your engine if it begins eating bearings?

There's only one correct way to build an engine; check EVERYTHING, EVEN NEW PARTS. The part you don't check is probably going to be the one that bites you in the a**.

BTW, the assembly is going to have to be balanced too, unless you bought the complete setup already balanced. That means rods, pistons, crank, flexplate/flywheel, rings, bearings, and damper.

Jake


[Modified by JAKE, 2:02 PM 5/26/2004]