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

There have been reports of push rod interference where they go through the block, but 1st on possibility of oil leak on the Chr. Apparently there is a possibility of it when using 241 heads on high deck Dodges. Tex Smith's Hot Rod Book has a photo of 51-3 head gaskets overlaying 354 gaskets showing differences between the 2.

 

Make sure that your head gasket has holes in all of the correct places then clean the casting and fill the upper portion with JB weld.

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JB weld sounds good. I wish I knew what the xtra holes were
for above the lifter access hioles. They are not shown on any
other heads. I'll use the gasket from a car 354 instead of
the truck gasket. The holes in the heads match all block
holes. The 331 heads are supposed to be 54's, have the good
ports. Had them magged!
Thank's, Rich

 

Rat Bastad has got a blown 330 Desoto in progress and has taken the time to show us the porting and polishing job he's done on the heads. Very impressive work! Makes me want to go out and clean up the heads I have layin' around...

Thanks Rat!

http://www.jalopyjournal.com/forum/showthread.php?t=344574

 

No sweat....some for us Desoto guys hehe.

More to come as we go along on this little project, stand by.

Rat

 

should i or shouldnt i have exhaust vavle seats intalled in some desoto 330 heads ? its just a mild sreet engine driven around town mostly but may be going on some long distance rat rod runs in the future. this hemi site is the greatest !!

 

Welcome to the Hamb. Be advised that the 'forum cops' will be knocking on your door any minute now to work you over for lack of an introduction. Oh, and lose the rat-rod term.

With regards to lack of hard seats, you might get 30 or 40,000 miles before needing another set of valves. The damage is progressive, not instant.


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Just a little word of caution here guys on porting. Looking at your heads. Intake port inside, see the little bump in the port wall? Be careful grinding in there. If you grind the bump out, you WILL be sleeving the pushrod hole. Lippy

 

ok there 73 rr guy my truck is actually a traditional hot rod anyway and also i have tried to do the intro thing here twice and each time i do when i try to post it the site asks me to log in again and my page is lost. back to the valve seat question, ive built several gasoline engines and dozens of diesels and realize how valves go bad and all that, but here is where all of the hemi experts ring in their knowledge so what i want to know is is this recommended as far as is there enough metal there to work with or is it critical as to only installing a certain valve seat and thats it or ? are there any guys out there that have alot of miles on a desoto without exhaust seats ? p.s. ill try my intro thing again, thank you greatfully

 

Since this is Hemi Head tech, I thought I would add a couple pictures showing the results of my new cnc program to resurface the Chrysler early hemi combustion chambers. This will really take the hurt out of those heads that have been sitting in the weeds for 50+ years. This will also true up the chambers, which were done manually by the factory when produced.
Most heads will need to be surfaced as part of the standard rebuild process, so chamber volume is not going to be adversely effected. This program can be modified to adjust the diameter as needed.

Programs for the Dodge and DeSoto are in the works.

 

Very nice , what kind of wood are we talking ?...keep us posted on the desoto

 

Do you have any experience with O-Ringing Hemi Heads? Any detailed advice to offer?

 

OOOOOOHHHH!!!!!! I may be sending you some heads for this!!!!

 

Hard seat inserts can be installed in any of the early heads, but depending on how much cleanup is needed this might be an opportunity to install a slightly larger valve to match the enlarged seat. Do not set the stock valve deeper in the seat as this will mess up air flow.
Like everything else, dollars can rule, or ruin, the day. Your overall budget may dictate whether or not inserts are going to happen.
A proper rebuild should get you 100k miles or more.



.

 

There are typically two grooves -- one in the head and a 'receiver' groove in the block . . . they must be concentric. Any competent machine shop that has the equipment and is used to doing this procedure should be able to do the job. The wire o-ring that goes into the groove (usually in the head) sticks up a bit (like .010 proud) - this adds the pressure/sealing to this area.

Also, you need to ensure that you're running the correct head gaskets and that you have good sealing around all the water areas (if you're running a wet deck). It can be a bit tricky to get the head gaskets to seal in the water areas in some cases - if you want to know more, checkout this article by FlatOut race gaskets. I'm using the RCC gaskets on my blown hemi - aluminum heads, O-ringed, etc..

http://www.flatoutgroup.com/news/newsDoc/CopperArticle.pdf

 

I recently finished porting my 330 Desoto and thought I'd throw some pics on this thread. I didn't read the warning above about the intake runner bump - guess I got lucky . The valve seat in the intake side was not touching for 1/2 of the valve. There is a lot of threads for and against valve lapping, I decided to lap the intakes ( about 1/2 of them had contact issues ). These heads were machined and assembled about 10 years ago and never installed. When I got them they were full of rat turds and a little spot rust. So the guides are not worn. I had Johnny Thomas put in the hardened exhaust seats. The exhaust seats all had perfect contact markings. A lot of work. I hope its worth a few ponies anyway.

 

Just wanted to add this. George sent me a link to a thread on another forum with some good information on head port volumes. Thought this would be good to know.

Keep in mind these numbers are on a website and not in a Chrysler book. I wouldn't rely on them, but maybe they will serve as good reference, if nothing else.

http://www.thehemi.com/forums/viewtopic.php?p=12254

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1953 Chrysler Firepower hemi 331 heads- 115 cc intake ports
1955 Chrysler Firepower hemi 331 heads- 175 cc intake ports
1955 Dodge Red Ram 270 heads- 100 cc intake ports
1955 Chrysler polysphere 331 heads- 150 cc intake ports
1956-57 Dodge 325 polysphere heads- 125 cc intake ports

I also had a net contact check his 392 Chrysler hemi heads, they had 145 cc intake ports

what I learned from this was, if you have a later poly engine, you'll gain nothing from the early small port Hemi heads, other than looks- the poly heads are superior to early small port hemi heads

the proof is in the measuring, and there is a definite need for all the castings to be poured out in cc's and documented, someone could write a resource on it, and it would sell- this is a grey area with early hemis/polys, no one ever documented all the critical casting volumes.

 

that cc's volume post was mine

you can add to it this:

early 51-53 chambers were 100 cc's, pistons were 2 cc's valve reliefs total

and I specifically deny Panic any permission to use this information in any of those cheap pamphlets he peddles, otherwise I'll sue him for copyright infringement of my net posts and research- anyone else can have at it

 

George posted this:
Car & truck heads through '55 have hardend valves & seats, after '55 only "Power Package" & 300 engines have them, plus Dodge & Chr hemis used in Dodge trucks. Still need info on marine & ind.
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I picked up a good set of 58 Truck heads (1730438-1) And would
like to know for sure these have the hardened seats?

Also can I use the passenger valve guides to replace the large stem
sodium valves?

Scooter: What did you end up using for a oil pan?

Thank's, Rich

 

If the head has a seat they are hardened, or they just machined the head w/o using seperate seats. If still nervuos, your machinist can test them. Pass guides are how you solve the stem size problem.

 

Thank's a lot George, I thought there was a material
difference. Shows my ignorance on these Hemi's!

The original set that came with my engine were
cracked, and as I checked 'today' are machined in.
The replacements I picked up have hardened
seats. Same numbers (1730438-1) !

Rich

 

I had an early pan off a '53 331 that was pretty banged up. I was trying to keep it with another motor that I have, but got tired of looking for a replacement. I hammered it out, cleaned up, and painted it.

 

I had the same problem looking for a pan. The E-bay pans are
for late engines, mine has the early bolt pattern. I went
ahead, and modified mine. Here's a few pics:
http://www.jalopyjournal.com/forum/album.php?albumid=11715

Rich

 

I thought I would show this post from another board written by Dan Miller...part of the Dan Miller/Gene Adams/HotHeads EMC engine team.

I get alot of emails asking if the main cap girdle is better than just 2 bolt mains, 4 bolt mains, or if it works at all. Once again I will state.....it works. Not everyone is going to need one, but for those who want a little extra piece of mind.....it does what it was designed to do.

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. This is NOT a paid endorsement. lol

Danny

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I noticed there was no direct section to add discussions on head studs, bolts, or anything else related to fasteners. I added it to this thread and changed the topic heading accordingly.

Here's a thread specifically on Cylinder Head Bolts and Studs:
http://www.jalopyjournal.com/forum/showthread.php?t=476273

 

What is suggested for refinishing the dome are of the heads ??? Mine have some rust pitting.

 

Tom Waters (TR Waters Designs) has CNC programs to refinish the combustion chambers in early Hemi heads. I'm not sure which heads he has the programs for, so you'll need to check with him.

Here is his contact/WEB site:

http://home.together.net/~twaters/

Hope this helps

 

I know this is an old thread, but I teaching myself about these old hemi's cause I have one now.
I found a thread from Bass about head gasket issues. It looks like the gaskets Bass had were for Rich's motor, & vis-versa.

Here's Bass's thread

http://www.jalopyjournal.com/forum/showthread.php?t=401522&highlight=gaskets

 

I know nothing about it

 

What s the max overbore for the dodge 325 hemi? .060,.090,.120? Thanks Jed