9.3-9.5:1 lunati bracket master II 536/567 293 dur advance it 2 degrees W timing set and it'll have small lope and won't need a giant converter or even need converter at all. Springs should be the 73815s I ran that setup W dish pistons and had very good street manners

 

Has anyone ever had any issues with the KB hypereutectic pistons?

I'm not going to knock Tim at all, I know he's the man when it comes to this stuff. I'm more specifically looking for details on the KB 2347 pistons.

Tried to call Tim to ask him directly, but he's busy haha

So I turn to you guys. Correctly gapped rings, KB2347 pistons with all of the other stuff I've got going on... What are the chances I'll see big issues down the road?

Cast pistons are a great replacement option, but they don't bump the HP up that much because they can't bump compression like Tim's KB pistons do.

There's a fine line I'm drawing between motor longevity and the "fun factor". I know I can't have both, but I just want to make the right choice on both my pistons and the motor overall.

Opinions, suggestions, comments are welcomed. AGAIN, I'm not bashing Tim in any way shape or form. I have just read a lot online about the issues with KB pistons in general (NOT TIM), because shops don't gap the rings correctly.

 

I've not heard of any problems with Tim's pistons. And he's sold a ton of them - which is a lot of aluminum pistons.

 

This is very true Gary. Thanks for chiming in so quickly.

Longevity is the key for my build. I want this truck until I die lol.

I also want to have some fun with it before I kick the can tho!!!! hahaha. Looks like Keith Black pistons may be my best bet.

If I was running the following, would I need to get ARP bolts for my motor?

- 400 motor - 0.030 over
- Decked block
- Machined heads to match block
- KB 2347 Pistons
- Stock Connecting rods /w matched bearings
- Crank turned /w matched bearings (I believe the shop is looking at 0.010 under just due to age of the crank)
- 1,200 rpm - 5,200 rpm hydraulic flat-tappet Comp cam (Stock-ish to mild build, good idle characteristics)
- Matched Comp lifters
- Stock sized pushrods (unless shorter ones are needed from decking block and heads slightly)
- 4bbl Edlebrock carb + Offenhauser intake
- 3-angle valve job
- New springs
- New valves
- long tube headers
- Stock Duraspark II ignition


Again, the quesiton is... with this set-up... can I get a 100,000 mile motor out of it? Do I need to go the extra mile and get ARP fasteners?

 

I think ARP's are cheap insurance. I used them in Dad's engine - and I also had the rods shot-peened, but that's not a usual step. But, I don't know what my offspring will do to this truck after I'm gone, so I'm doing all I can to make it live.

 

I've done over 45,000 miles since building my engine 5 years ago, and the only issue I have is trying to stick to the speed limit !!
(Mild performance parts like you're using)

I used KB Hyper pistons. No problem.

Ring gapping and positioning is ultra important. Instructions might accompany the rings.

It doesn't hurt to double check the builder's work.

With regard to decking, and thus compression ratio, have the builder assemble the engine, measure the deck, then disassemble prior to machining and final assembly.

Having ALL measurements will ensure a 100% planned and built engine.

Yes, with regular servicing, you will easily see 100,000 miles and then some.
And that includes ''the fun factor''.

I agree with Gary, ARP's are a cheap insurance.

 

Great info fellas.

Block, heads, oil pan, and valve covers are all getting hot tanked today. Guess we'll see what the results come out with.

Quick question on driveability with a 9.0:1 compression or higher engine.

With the KB2347 pistons, I'll be running higher compression, which may require higher grade gasoline (than the 87 octane) to keep the motor happy without detonating.

What compression ratio are you guys getting from your set-ups and what kind of gas are you running to keep the 351/400 happy?

 

Mine is at 10.5:1, but it has aluminum heads and that allows about 1.0 more compression than with cast iron heads. I haven't installed the engine yet so I don't know for sure, but Tim assured me that it'll run on 87 octane. However, even if it takes 91 I'll be happy.

 

That's a fairly high compression ratio. I'm hoping to achieve something like 9.2:1 when I'm done, heck even 9.0:1 would be a huge improvement for this old piece of iron.

Glad to hear you'll be able to run pump gas Gary. What's the recommended timing Tim gave you to run 87 octane?

I've been doing a fair bit of reading to understand manifold vacuum, ported vacuum, octane in relation to CR, and other stuff related to breaking in the motor when I get it back... assuming it passes the hot-tank & magnaflux tests.

 

He hasn't said yet as I don't yet have the engine. Soon, I hope.

 

Aaron-71,

Use the Keith Black hypereutectic pistons from TMeyer and don't look back. They are a good piston, just make sure you give them enough ring gap.

Also don't be too wimpy on the cam. The long stone 400 is naturally torquey and can use a pretty good size camshaft and still maintain street manners.

Use an ARP oil pump drive shaft and rod bolts at minimum.

 

Good advice. And, I forgot to say that cam duration/overlap reduces dynamic compression, so a bit more cam than you might otherwise use reduces the tendency to ping or detonate.

 

Good advice fellas. Thanks for the feedback.

Still waiting to hear back from the shop on how the block looks - hopefully sometime this week here (was hoping for last friday, but you all know how that goes with machine shops lol).

Why ARP bolts for the rods only? Why not for the mains as well?

I was honestly looking at getting the ARP oil pump shaft at a minimum - it's pretty cheap and mine looked like it had a good life and needs a replacement.

These are the part #'s I'm looking at:
ARP Rod bolts: Kit #: 154-6001
ARP Main bolts: Kit #: 154-5004 (this one needs to be checked, doesn't say if its for 351M/400 - only states for 351C.
ARP Oil pump drive shaft: Kit #: 154-7905

 

I'm running a static compression ratio (SCR) of 10.42, also on ally heads, closed chamber, and using 91 octane. (There is no 87 octane here !!??)

Before I forget, your cranking pressures on page 1 are excellent, and the vacuum reading was healthy, especially if your advance timing is ported.

You said that you ''hoped for 9.2 compression''. Stop right there !

You can predict what the SCR will be, so hope for nothing !

I don't know what the maximum safe SCR on an iron open chamber head is, so maybe double check with Tim, running 87 and/or 91.

If he says 9.5, for example, then aim for that.

Also ask him if 0.035'' squish is acceptable.

That's about the lowest you can go, and go there if need be (to get say 9.5) with a suitable good quality head gasket.

The higher the SCR, the more efficient the fuel combustion, the happier your wallet will be.

Once you've worked out the SCR, only then should you choose a cam.

With regard to Dynamic Compression Ratio (DCR), the cam timing for the intake valve closing is the key number and you'll want the DCR in the mid to high seven range.

Closing too early, and your engine will detonate all day.

Your cranking pressures were +/-140. You could see as high as 180. (Nice!)

With regard to ARP bolts, consider them for the heads too.

With regard to the oil pump, consider a good one. (Melling ?)

When you are able to choose the cam, buy a complete kit with matching springs etc.

Ensure that the builder measures every spring pressure, and that he shims them were need be.

Depending on what piston rings you get, read the instructions, and ensure that the builder uses the correct honing grit. (Yes they differ)

Check how much you are allowed to machine off the heads before you do them !!

When your engine is assembled, and assuming you have a 9.5 SCR, your ignition timing will be too advanced. It will need to drop from 34-36 to say 30-32. (A reflection of the improved combustion efficiency.)

Laterz,

 

Well said, and good advice.