HEMI Tech- Block, head, porting/polishing, and gaskets

Before doing anything, sonic check each hole, and then keep the bore to the minimum needed to clean it up. These engines have core shift issues. If you want more grunt than the stock piston package provides then use a 10:1 forging. Yes, we sell them.....

Oh yeah, go back and do an intro.

.

 

well said!

 

head I.D.
casting #1677441-1
they are not in the book, they look to be 354 heads, they have water ports on both ends

 

354 Industrial

 

I had a request from a fellow Hamber for information related to valve springs and whether or not the spring seats can be cut for longer springs.

I do not think it is good practice to cut the seat deeper since this is a fairly thin spot to start with. Here is a pic of a 392 head that we cut:

The angle is not the best but you get the idea. The biggest concern is the lack of casting control in this area; it could be extra fat or extra thin.
Sonic checking the area will work only if the correct probe is used and the entire area is scanned.

For those with a die grinder in their hand, note the wall thickness at the top of the intake port, by the guide.

.

 

I thought I would share a couple "spy photos" of my new and improved HD main cap girdle available for the 331/354 and 392 Chrysler Hemis.

My new HD girdle now picks up all ten of the main bolts, vs 9 of the bolts on the std versions for Chrysler, Dodge, and Desoto. The new girdle does require very minor clearancing of the stock oil pump for the bolt. It clears the aftermarket pumps (SB Mopar with adapter) without any modifications.

The HD 331/354 girdle is now the same overall width as the 392 girdle, and includes the rod bolt clearance notches.

 

I'm not seeing any images. :-(

David

 

fixed

 

Here's an interesting thread on head porting that TR Waters put together.

http://www.jalopyjournal.com/forum/showthread.php?t=667878

 

On the topic of valves from another thread, the marine 331 and 354 used sodium exhaust valves and hard seats.
Also, be aware that there are 331 truck and industrials that used 1556157 (555) heads which also had the large stem sodium exhaust valves. The same goes for the Dodge 270 head 1554132.

 

Tom Waters Girdle
by dan miller » 13 Nov 2009 10:17
We were having trouble with the front main cap moving around on our 354 EMC early hemi. The engine is partially filled, cryo treated, and has 4 bolt splayed main caps on the center three mains.

We had no issues up to about 550 horsepower. We noticed metal transfer on the front main cap at around 575 horsepower, and it started to become an issue at 600 horsepower. We installed a Tom Waters girdle and made 121 pulls, many over 650 horsepower. Upon tear down, we observed that the front main is now solid. Zero movement/issues.

We also installed one of Tom's girdles on our Junior Fueler, about 850 or so horsepower. At these power levels, main cap movement is a fact of life, and one just has to live with it. We only have about ten passes on it (and haven't torn it down yet), so it's probably too early to tell, but I'll advise when we see something. It might not cure things, but I'm betting that it will be of significant help.

A very nice product. Inexpensive, very high quality, came with all parts necessary, installed easily - a true bolt on. I highly recommend it.

Danny

UPDATE​

[FONT=Times New Roman, serif]We run the JrFueler @ approaching 900 hp, and have zero issues. The mains walk around a little, but much less with your girdle. We have about 40 passes on a new block, and there is main cap movement, but significantly less than without the girdle.[/FONT]

******************************************************


FYI.....10 bolt girdles are now available. (vs 9 bolt)
​

 

I thought I would post up a couple pictures of my new torque and/or honing plate for Chrysler early hemis.
I made this from 1.5 inch 6061 aluminum. It is made with a 4.075 bore. I used aluminum because I have an upcoming project which is using aluminum heads.

 

Nicely done - wish I had one! You don't happen to have a CAD or DXF file of all the bolt hole and bore centerline locations do yah? I'd love to have my machinist make one of these for my 392 projects. If you do and you'll share, I'll be happy to create a 3D CAD model and share back.

B&S

 

Question:

I'm trying to buy some 5/16" dowel pins that locate my heads to the block, but I've found inconsistencies in the diameters between sellers. One company called "Classic Engine Supply" sells dowels that are 0.3125" in diameter (a true 5/16"). Mr. Gasket says it's dowels are 0.316" in diameter. Both companies claim the dowels fit the same engine. I don't have either sets in my hands, so I can't be exactly sure what they measure.

I've gauge pinned the holes in my 392 block and they come in right at 0.309" diameter. I'll admit the holes are not as clean as they could be, so they're probably a little bigger. I'm nervous that even a 0.3125 pin (5/16th) is too tight. I can't imagine needing more than a couple of ten's of interference to hold them in the block.

What size pins do you guys usually use, and can a standard hardened alloy dowel pin be used? The kind of pin commonly used in fixtures and such. They typically measure 0.31252", or two tenth's over. You can order them under by two tenth's as well.

Thanks in advance for your time.

David

 

How about using the .3125 pins and fit them to your somewhat-small holes...assuming the center to center distance remains compatible...

The original design, was, I'm sure, relying on the pins to keep the head in place whilst you start a bolt or two, not to locate the head to any 0.xxx location.

.

 

Thanks for the reply. I'm over thinking this thing. I'll clean the holes and just make some pins to fit.

 

The original dowel pins I just measured are at .313

 

I thought I would post these pictures up for some show and tell. This girdle is from a 354 hemi jr fuel engine which broke a rod. The block is being magged for cracks in the main webs. The general consensus is that whether or not the block is cracked or not, the damage would have been much greater to other parts had the girdle not been installed. The girdle prevented the broken rod from breaking out the bottom of the cylinder into the water jacket, which happens 99.9% of the time with a rod failure.

There are those who will argue that if the girdle wasnt there, and if the rod had broke close to the crankshaft, and if the piston didnt drop in the cylinder...well...you get the idea.

 

Enjoy

 

Bump- I've got a question for the masses, what if I found a set of 331 early{'53} heads with cracks between the spark plugs like my old spare 392 hemi heads had?...can this be repaired or are another set of heads in order? The area in question "should" be the water jacket area as I recall. I let my old 392 hemi go eons ago due to both sets of heads having the above mentioned cracks...back then there was no real parts support{early '80s}...now there is far better out there. I'm looking into a '53 331 hemi extended bell for my '40 plymouth sedan...the reason I ask.

 

...find another pair of heads...

.

 

Yeah, & 54-56 would be better heads.

 

First time offered...anywhere. This auction is for my newly released early hemi oil filter mount to engine block gasket. Precision laser cut for an exact fit. This can be used on all makes and sizes of early hemi engines. Previously unavailable unless you bought a complete gasket kit. Made in the U.S.A. of N-8090 premium gasket material.

N-8090 has a latent cure nitrile butadiene rubber binder and reinforced cellulose fiber. It has excellent oil resistance, good sealing characteristics, and is intended for applications with short duration maximum temperatures up to 180°C (350°F).

 

Picture doesn't seem to be loading, Tom.

 

It's there on mine.

 

Well I saw it yesterday , but not today.
There's something going on with pics on the Hamb today.
Ryan is on it !

 

On my 291 desoto heads is there any benifit to installing bigger valkves and doing port work over just installing 330 heads. Are they just as likely to crack once there are bigger valves cut in? Is there enough material in the castings to open up the ports to the size of a 330 head. i know the 291 heads dont seem to crack but is the only reaso being the extra material

 

I hope some0ne still comes here once in a while that can give me some definitive info on the differences between the '51-'53 331 intake/exhaust ports and those on the bigger-valve '54-'55 heads, other than the shape of the exhaust exits. I am finishing up with polishing the exhausts from the valve seats to the exits on my '51 heads, and just grinding off the casting flash on the intakes. Next step is to the machine shop to have the valves and seats done. If, BIG IF, the valves or seats have to be replaced, how much would I gain by stepping up in size to the 1.94" intake and 1.81" exhaust valves? I have had the block bored out to a 354, and will be using stock 354 slugs, nominal CR 9:1, the Hot Heads No. 2 hydraulic cam, .465 lift, 221 Dur .050, 111 ls, their dual-plane intake and a 650-675 cfm single 4-bbl and headers. My heads are "free" in that they are the factory ones so I have only the cost of magging and pressure testing in them so far. The valves, seats and guides are in good shape, provided there is still enough material left for a regrind. If not, it makes more sense to me to go to the bigger valves rather than starting from scratch with a pair of unknown heads, unless there would be little or nothing gained.

 

According to a Mopar tech report the '57 Dodge heads take short reach plugs & the '58 takes long reach.