One torque plate / honing plate, or two?

FarNorthRacing

FarNorthRacing

New Member
So I'm rebuilding a Dodge Stealth (Mitisubishi 3.0l V6 6G72) and on the list of things to do is new pistons. New pistons means machining the block to fit, so I'm looking at at least a hone, and maybe a bore+hone.

Honing means torque plates, and there's no way no how that any engine machine shop here in backwoods New Brunswick will have anything that fits up.

So I'm going to make at least one.

I'm wondering though if the proper answer isn't *two*:

1. I'm going to switch from head bolts to head studs. One torque plate means exposed studs on the block while at the shop, which seems like damage waiting to happen;

2. If I deliver the block to the machine shop with the plates in place, already torqued, then I know they have been properly tightened. Otherwise, I'm trusting the shop to do it right; and

3. I can't help but wonder about which stresses distort the block - meaning that as many of the highly torqued fasteners that go into the block should be installed at the time of honing, so that the block is accurately stressed as it would be once installed.

Thoughts?

Has anyone ever glued strain gauges into cylinder bores, started tightening parts down, and measuring the resulting strain?
 
Piston ring manufacturers are researching cylinder bores and what happens to them constantly.
And, of course, what the machinists/rebuilders are doing out in the field.
 
http://www.bhjproducts.com/bhj_content/products/honingplates/hp_applist.php

you can probably buy a torque plate here

improvements, resulting in the models available today.

This list reflects current BHJ Honing Plate applications, as of September 2015. Please contact us for applications not listed, custom configurations and technical information.A-B, C, D-F, G, H-L, M-N, O-S, T-Z

Maserati 2.5L V6 (Biturbo)
Maserati 3.0L V6
Maserati 3500, 3.5L, DOHC 6-Cyl
Maserati 4.7L V8
Maserati C114-03 2.7L V6
Mazda 1.6L B6ZE(RS) 4-Cyl
Mazda 1.8L BP 4-Cyl
Mazda F Series 4-Cyl
Mazda MZR/Ford Duratec 2.0L, 2.3L 4-Cyl
Mazda Z Series 4-Cyl
Mazda 2.5L K Series Turbo V6 (1992-2002)
Mazda 3.0L MZI/Ford Duratec V6
McGee Quad Cam V8
Mercedes 4-Cyl
Mercedes Diesel 5-Cyl
Mercedes V8
Mini Cooper Tritec R53 1.6L 4-Cyl (2001-2006)
Mitsubishi 1.0L 3B21 3-Cyl (Smart Fortwo North America)
Mitsubishi 2.0L 4B11 4-Cyl
Mitsubishi 2.0L 4G63 4-Cyl
Mitsubishi 2.3L 4G64 4-Cyl
Mitsubishi 3.0L 6G72 V6
Mitsubishi 3.5L 6G74 V6
Mitsubishi 3.8L 6G75 V6
Nissan A Series 4-Cyl
Nissan CA Series 4-Cyl
Nissan H Series (R16) 4-Cyl
Nissan KA24 2.4L 4-Cyl
Nissan L Series 1.6L 4-Cyl
Nissan L Series 2.4-2.8L 6-Cyl
Nissan RB Series 6-Cyl
Nissan SR20 2.0L 4-Cyl
Nissan TB48DE 4.8L 6-Cyl
Nissan U20 2.0L 4-Cyl (1967-70 Datsun Fairlady & Sports 2000)
Nissan VG30 3.0L DOHC V6 (8-Bolt, Including VG30DE, VG30DETT)
Nissan VG30 3.0L SOHC V6 (13-Bolt)
Nissan VQ35 3.5L V6
Nissan VR38 3.8L V6
Nissan Z Series 4-Cyl
Novamotor F3
 
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By the time you take into account shipping and exchange rate, it is *way* cheaper to build one myself. I can build 2, maybe 3 for the price of one of those BHJ plates.
 
I hope that works out! while I fully agree the price is rather high,
most people don,t have access to the machine tools to do that type of work,
or easy access to the steel plates that they are milled from

Core shift is a result of a block, cylinder head, or other engine casting shifting in its mold when the molten metal is poured in. When core shift occurs the cylinder bores, lifter bores, main bearing and cam tunnels shift from their blueprinted positions. If the shift is significant, mechanical problems can occur and some cylinder walls may be critically thin. This is especially of concern if the engine is to be used for racing applications.

The only way to guarantee cylinder wall thickness is to have the block sonic-tested, but this can be difficult when you go to purchase a used engine.


Core shift example


On engines with in-block cams, you can always take a look at the cam bearing bore. If it is noticeably offset in its machined boss, you should suspect core shift.
 
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YES OBVIOUSLY VERTICAL CORE SHIFT WOULD TEND TO BE LESS POTENTIALLY HARMFUL,
AS THE RESULT WOULD TEND TO BE,
BOTH BANKS WOULD THEN TEND TO BE DEALING WITH SIMILAR MECHANICAL STRENGTH/WEAKNESS
but OEM production run blocks tend to be rather thin and I'd again point out that the DART block is significantly thick, and cast from a harder and stiffer alloy and uses a more rigid thicker wall casting.
yes its expensive but its also much less likely to have issues from stress and your very likely to need to put $800-$1500 plus into machine work costs just to get a OEM production block any where near ready to build into a proper engine and then its still significantly thinner and weaker
  • CNC BLOCKS N/E Said:
This is a factory 454 block .030 that was machined by another shop. I have seen work from this shop many times and their work has always been spot on. This is a marine build went to plate hone the block and measured the cylinders they were .0035 distorted. I can not stress enough that on factory blocks plating honing is a must to achieve good ring seal. People say the rings will break in LOL I have seen circle track engines with rags around the breathers for 2 or 3 years leak them down up to 35% leak down. I have always said its best to do a leak down 40 to 50 degrees BTDC or after TDC. Here is an article I did on plate honing years ago
https://www.chevelles.com/forums/148-2005/93364 -va...








http://garage.grumpysperformance.com/index.php?threads/flex-hone.9538/
 
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