What's the current favored new Harmonic balancer and spacer options for a neutral balanced stroker.

Many new steel balancer spacers out there.  Precision Oil Pumps has some that are nice. 

For a balancer, I use a lot of Powerbonds.   

Had to cut a brand new BBM block to 10.145" once because the decks were that out of whack.

What was out of whack? BBM machined the block with a taper? How much?

The low spot was on the intake side of the deck if I remember right, been a few years back.   It was off about .020".  Had another block that needed a sleeve because of a porous spot.  Had yet another that was porous to the outside of the block leading from an oil gallery.  Nothing like priming the pump and watching oil appear on the outside of the block.  Good times.

Quote from: Joe-JDC on September 23, 2023, 09:38:57 AM

No one has asked how much clearance between the bottom of the intake and the china wall.

See third sentance of post #5. I just call them valley rails instead of China wall.

Brett builds engines for a living and I build them for fun so if he says it's not uncommon on an OE block, then I believe it, but if any block of mine were out of square .025" I wouldn't be building on that block because if the deck is out that far, where's everything else at dimensionally? I guess I'm fortunate that all my builds in the last 20 years have been on aftermarket blocks that needed to be finish machined anyway.

Besides, if we're only talking .020" in the extreme, the OP's opening post says "it (the intake) sits way higher than the heads".....not sure what that means to you but it would be something >>.020" to me. I wouldn't sweat .020" of mismatch on something as benign as a valve cover gasket, but the position of bolt holes and ports would likely follow. Sort of depends on how you value the intake, but I'd also think twice before cutting an intake to match (and potentially every other intake you might ever fit to that engine) unless it was truly the culprit responsible for the mismatch. Some of my lids have a lot of work into them and I value them highly.....thus my remark, I think I'd be looking for why it's way too high in the first place. -Different strokes for different folks I guess.

Best,
Kelly

Had to cut a brand new BBM block to 10.145" once because the decks were that out of whack. 

Quote from: blykins on September 21, 2023, 09:45:27 AM

This is not abnormal.   As a matter of fact, I have to cut every intake on almost every build by the thickness of a gasket.   It's also not abnormal for one side to sit differently than the other side. If you have a borescope, you can check port alignment with the intake sitting on the heads with no gaskets.  If the roofs of the ports line up, then I'd cut the intake flanges and bolt it on.

Hmmmmm....seems pretty strange. Assuming the valve cover rails on TF heads are the same height as OE (are they?), then how did that OE intake ever fit anything? As a first order of business, I think I'd be checking how the mounting bolt holes line up with gasket installed and then the port roofs second. If the intake lands on the sides of the bolts before the intake seats...... that's no-good.

If the bolt holes and ports line up, you cut the VC rail height on the intake. If they don't, you cut the face of the intake until the holes line up, preferably with the intake holes sitting slightly high so they center when you pull the lid down. -Just me.

I suppose, if everything lined up great except the valve cover rail height, and you didn't want to cut your OE intake, and the valve cover rail height difference was relatively modest, you could just make up the height difference with a partial gasket under the full gasket. -Bring your gasket adhesive!

On other engines, milling a step in the intake face to accomodate the valve cover overlap is pretty common but FE intakes are unique with the shared valve cover rail feature.

Best,
Kelly

It's not abnormal because we normally have to cut the blocks to make sure they're straight and square and parallel to the crank.   Factory FE block deck height is nominally 10.170".  However, they're sometimes out .020" from front to back, side to side, etc., (even on aftermarket blocks that are new), so it makes the intake sit proud.  It's not uncommon to end up at 10.145-10.150" even on brand new blocks due to manufacturing issues with them.   It's certainly common to end up down there with factory blocks. 

I've had situations where the valve cover rails just needed to be cut down, but it's been few and far between.  It's most often cutting the intake flanges.  Generally they will need at least clipped anyway, because they're not straight/flat after 50 years.

The EFI intake does have a common plenum for manifold vacuum. 

Richard,

I've used two head porters in the past for Tunnel Port builds.  Neither of them have ever suggested using a larger valve.  I think that's because of two reasons:  1.  Not enough room.  2.  A 2.250" valve will support *a lot* of horsepower. 

Here's a picture of a Tunnel Port chamber with a 2.250"/1.750" valve pair. 



The seats are already butted up against each far enough that you don't end up with two true complete circles. 

In addition to all of that, an engine needs a given volume to make a specified horsepower.  We have to watch about making things too big as a big valve/big port can make for a lazy engine if everything below the head is not sized to match it. 

I will tell you that I don't build a ton of Tunnel Ports, probably 6-7 total.  They're just not in high demand and a lot of guys want to hang onto the original parts. 

I will also tell you that in all of the FE's I've ever built, including engines with TFS heads, ported TFS heads, CNC ported Edelbrocks, etc., etc.. the engines that have made the most hp/ci were Tunnel Port headed engines. 

This 1x4 TP intake, modified by Joe Craine, averaged 490cfm between all 8 runners.   I'd be willing to listen to some arguments about how the Tunnel Port heads are at a detriment because of the tubes in the intake, but that would be about the extent of my involvement.  I think I even made the same comment years ago, but my outlook has changed.

375 cfm without an intake and 330 or less with intake attached.

Source?