308 rebuild

Majumbo

Ive been currently working in Colorado in the oil fields and am home for one week before i go out again.  I have a 308 block im am wanting to rebuild.  Im losing my mind unfortunatly. I have many questions and if someone could bare with me id like somehelp. some background info, im planning on building a 7xish engine, meaning bigger valves, randy or cliffords ground cam, roller timing chain, port/polish, beveled lifter bores, 1/2" arp studs, arp rod studs running an edmunds finned aluminum head and edmunds 2x2 intake, mallory distributor. im trying to build a good street engine with a decent idle but am not stuck on a nice idle if the power gain is there with bigger cam. Basically what i have is a 308 block, crank, cam, rods and pistons and a running 262 with low compression to rob parts off of. im planning on buying dale coopers engine kit for new piston etc.

1. I know this topic has been beaten to death but should i get hardened valve seats? my block casting is 304539 CWC and the serial number is 211143.

Id like to not have to buy lead additive so if its potentially a problem i will have the machine shop throw new seats in. I gave Randy Maas a phone call and he said if they are not cracked dont replace them.  what are your guys thoughts on it.

2. Wondering what sizes all the freeze plugs are. Does anybody sell a kit? Also i plan to mod the block for full flow, does anybody have CLEAR instructions on how to do this? if i have to buy a tech tips book or something i will,

3.  7X relief is it worth it? im planning on putting 2 inch intake valves, if anybody has a diagram or instructions i can get/ buy that would be awesome.

4. give me the low down on 1/2" studs, should i have the machine shop do the block/ head?

5. block prep, i plan to magna flux and hot tank, and im gonna use pipe cleaners, what else is good? i also see that hudson blocks came with painted insides. ive seen some people do this and i would like to whats the 411 on that.

6. im a diesel mechanic and rebuild "Big 15 liter sixes" regularly, not going to lie im kinda freaking out on this big 6 please help

maasfhcenturylinknet

!.  I don't think hardened valve seats are necessary.
2. Yes I have a kit of freeze plugs.  I also lhave engine kits available for '35-"56 hudson 6 & 8's   Contact Walt  for     his filter system. 
3, Yes, the relief is worth it if putting 2" intake valves in-- only if using the 7X 391-268.  Has good idle and great   power from 60 to 90.  I you want to use the .372-254 can you can expect performance improvement with stock valves.  A mild relief is ok but not necessary.
4.  1/2 inch studs or bolts are a plus.  Have a machine shop that has a mill to drill and tap so they are        straight. If using bigger valves you will need to clearance the head.  Have the machine shop due this.  I use valve seat cutter to achieve this.
5.  I have all my blocks that I rebuild for people put in a furnace and burned then tumbled with stainless steel        shot.  When finished it looks like a new block -no rust anywhere.
6.  Calm down.  Plenty of help and experience around.  We'll help you get what you want. 

RL Chilton

Generally speaking, I agree with everything Randy has said above.   I'll add my .02 in so that you can weigh all of your options.

1.  You'll find a lot of differing opinions on the valve seats.  I agree with Randy that that they really aren't necessary.  This is because your 308 block is not cast iron, but, rather a chromium alloy, which is incredibly dense, hard and tough (way more than cast iron).  That said, hardened valve seats on your exhaust vales (at least) can not possibly do any harm and very well might do some good.  

2.  Buy the kit, it's easier, you don't have to make a list, etc.  While you are at it, buy two and you'll have extras on hand if you ever need it.

3.  Again, you will get differing opinions on 7X mods and relief cutting, etc.  It is my opinion that if you get a hotter cam and make the engine breathe properly, you will have all of the horsepower and especially torque that you could want in a street engine.  I think the relief cutting is good, as it makes for a better breathing engine, of which I'm a big fan.  I think the bigger valves is overkill (unless you are building a racing engine and not a street engine).  308's all ready get lousy gas mileage and bigger intakes are going to make it worse.  Again, a hotter cam will do wonders towards the sound and power you are looking for.  As far as breathing better, gasket matching and porting/polishing (along with the relief cuts), headers or split dualies will make these engines breathe free and clear, which ups your power exponentially.  Headers alone (or split dual exhaust) can give you an easy 20% more HP.  It's the cheapest  bang for the buck (or $/HP) there is.  

4.  Yes, 1/2" studs.  If you up the compression at all by decking or shaving the head, 1/2" studs will keep that head gasket from coming unglued.  If you vary away from stock, you've got to cover your bases elsewhere.  Have a machine shop do all of this for you.

5.  Painted insides?  Looks nice . . . not sure it adds much benefit other than originality.  Seems like it would hold heat in, which as you know is a the #1 killer of ICE's.  

6.  Agree with Randy.  Keep it calm.  One step at a time.  You're doing the right thing, and making your plan first.  Once you decide on your plan of action, stick to it.  Do your homework and make the best decisions based on the info you have gathered.  HAVE FUN!!

RL Chilton

That makes sense, thanks Ken!

dougson

Didn't know about the red glyptal coating, huh. For maximum sump ventilation and cleanliness I would suggest PCV instead of blow by. Otherwise I agree with everything above. My "7X" build runs great, smooth, but likes gas stations....

Chris Smith

Nice tube type header and a low restriction exhaust system will make all the internal mods worth it. Moroso makes a block brush kit for around $40 that has everything you need to clean all the orifices. Also suggest replacing the oil gallery soft plugs with screw in plugs. I use red insulating varnish from a rattle can on the inside of my engine blocks and had no issues with it. Seems to keep the oil cleaner looking between changes. What's the story on "beveled lifter bores"? better lubrication around the lifter?

RL Chilton

One more item of note on the valve seats.  Two significant changes have transpired since these cars were new that affect them (excluding any modern modifications).  They are the quality of oil and the quality of the gas we put in them.  

Oil is better.  Period.  Synthetics are even better than that.  

Gas is poorer. Considerably so. (Hudsons don't like drinking corn, by the way!)  Modern gas burns slower, and subsequently, burns HOTTER.  Heat= #1 killer of ICE's.  So, with that in mind, it seems to me that hardened seats are pretty good insurance.  How much?  Don't know, that's a question for an engineer, which I am not.  But, I think it would be a good question to ask.  I stick with what I said earlier, that they can't hurt, and could very possibly help.  

BillUSN1

Russell,
I think were heading down a slippery slope with the oil.
I agree that modern oils are better but now they have gone to the worse side for modern standard oil in a flat tappet engine.
So it's either run a good zinc additive or I run 15w40 diesel oil in all my classics now. But I still check the manufacturers zinc content. They seem to change formulas all the time with the latest emissions requirements.

I'm really glad to see this thread started since I'm in the planning stages of my 262 build.
Lot's of good info, so please keep it coming.

RL Chilton

"I think were heading down a slippery slope with the oil."

That's funny, right there!  

Agreed.  There's vastly differing opinions on zinc additives, which I won't get into here.  Seems as though classic car owners have been knocking around debates on Zinc additives for years and years now.  We should update an old thread on the subject if anyone has anything new to offer.  

Majumbo

I'm not trying to cause a war or anything. Thanks for the info. I'm headed back to co today so a month from now When I get back my block will go to the machine shop. Then I'll buy the engine kit and what nots.

kerry

Where can I get a hotter cam for 308

Ol racer

Kerry,

 Contact Randy Maas. He offers several different Grinds depending on your application...

Browniepetersen

There is a lot of great information in this post.  I have just finished the rebuild of my 308 and now have it up and running (running great) after some head scratching.  One point to consider on valves and valve seats.  You want them to be of equal hardness.  Often the Hudson 308 block is the harder of the two.  Might consider a softer seat that matches the valves to maintain consistent wear.  One point on your cam.  Maas has four different mills available.  Have a good discussion with them before you make your decision.  I have my engine built to the "beyond 7 X configuration" but wanted a driver car so my cam is on the mild side.  There are some great idea along this engine build but weigh each idea and do not be swayed by some of the off the wall ideas.  By the way, I use oil for diesel vehicles in my engine because of the zink content and I also run the gas without "corn" with a lead additive.  Enjoy the process.....  And drive them like you stole it.....

Kdancy

Crane Cams has 4 or more Hudson cam profiles on record and will grind your camshaft to whatever profile you request. I've had them do both Studebaker and Hudson camshafts. Very good guys to deal with. http://cranecams.com/

Kdancy

http://openforum.hetclub.org/discussion/167650/hudson-camshaft-profiles

More camshaft grind/profile info-----
http://www.hetclub.org/forum/discussion/166655/306344-camshaft-just-profiled