From owner-fsj-digest-at-digest.net Sun Jan 30 16:58:45 2011 From: fsj-digest fsj-digest Monday, January 31 2011 Volume 01 : Number 3694 Forum for Discussion of Full Sized SJ Series Jeeps Brian Colucci Digest Coordinator Contents: Re: fsj: 304 vs Stroker 6 fsj: 304 vs Stroker 6 vs 360 RE: fsj: 304 vs Stroker 6 Re: fsj: 304 vs Stroker 6 vs 360 fsj: Freeze plugs and front clip. FSJ Digest Home Page: http://www.digest.net/jeeps/fsj/ Send submissions to fsj-digest-at-digest.net Send administrative requests to fsj-digest-request-at-digest.net To unsubscribe, include the word unsubscribe by itself in the body of the message, unless you are sending the request from a different address than the one that appears on the list. Include the word help in a message to fsj-digest-request to get a list of other majordomo commands. ---------------------------------------------------------------------- Date: Fri, 28 Jan 2011 23:07:21 -0600 From: Kim Tesar Subject: Re: fsj: 304 vs Stroker 6 Woops, check the math on that, 304/8 = 38 cu in/cyl. ////// On Jan 28, 2011, at 10:42 PM, Kim Tesar wrote: > Hi all, > > Jim, I remember you suggested considering a 304 as a replacement in > the J10, instead of a stroker 6 build. > > This has got to have some merit. > > It seems most people spend time trying to get these motors to > breathe. The sixes and eights have the same size valves, > 1.94/1.5. Good stroker builds show about 265 hp, maybe 290 lb-ft, > but the sixes have the longer stroke. Which have to move slightly > more air per cylinder: 360/8 = 45 cu in,, 282/6 = 47 cu in > (stroker 4.6) > > Getting bigger valves in a 6 cyl head, there are some on ebay with > raised ports and beautiful machining for $1600, um, I don't think > so. And by the time you're at that level, you're thinking roller > cam = $1100. This is starting to get silly. > > The 304 must be more efficient at moving air, right out of the box, > if it uses the same heads as the 360 with an undersquare bore/ > stroke ratio... 304/8 = 32.5 cu in per cylinder. And you get the > cross flow head with better intake runner design, and more cubic > inches out of the box than the stroker. Less money would need to > be invested in head work to improve the flow relative to the size > of the motor. > > There's a 304 on Craigslist in San Antonio for sale, in good shape, > for 800, maybe that's a better go. > Any other thoughts on this? > > - Landon ------------------------------ Date: Sat, 29 Jan 2011 00:58:22 -0500 From: Mark Wallace Subject: fsj: 304 vs Stroker 6 vs 360 Landon - The 1972 and later AMC 304, 360, 401 heads will flow better than the "Camel Hump" Corvette heads that were the holy grail of the Bow Tie set right up until aluminum aftermarket heads became affordable to the masses. That being said you can get a big cam, big valves, big carburetor, big manifold, big headers, big exhaust but without port work a lot of what you are doing is opening up the big end of the funnel. That being said with 235/75 15 tires and a 3.31 gear the engine is winding about 3000 rpm at 75 mph. Port work and big valves and big cams are really more for high revs. Not that I wouldn't do port work on a no expense spared engine for a my Wagoneer. If I were building any engine be it for a Sport car (got one of them) a work horse pickup (got one of them too) or a Full Size Jeep I would bump the compression up. I don't think I would go any lower than 10:1. AMC V8's are apparently tolerant of going quite a bit higher. Don't know about the sixes. Too much higher and you also need to get into stuff like forged rods, forged crank, and forged pistons. Big torque comes from big compression. If you are looking at the V8 route I'd look into a salvage yard 360. If you can start it and see that it has good compression, good oil pressure and no rod knock even better. When I lived in New England you could buy rusted out Wagoneers all day long with good engines for $400 or less. I suspect that you could get your $400 back on the ebay. (my last parts car turned me a profit) You might take a look at what's out near the sea in Texas. I can check Albuquerque yards for you. I have a built 360 that I have really enjoyed. It's plenty powerful enough to pull a sports car on a trailer. I am pretty sure I have had 6000 lbs behind it for a long highway run. It's big downside is just how thirsty it is. I built it in the summer of 1995 and there are things I would do differently if i were building it today (like more compression) but it's been a great engine over the years. Mark Wallace 81 Wag ------------------------------ Date: Fri, 28 Jan 2011 22:11:58 -0800 From: Jim Blair Subject: RE: fsj: 304 vs Stroker 6 304 is fine for power and better than 360 on fuel. I would build a fresh one for about $800 with 4.0L pistons in it (some AMC guys have done it. Could be more to it) 304 is same stroke as 360 (they share a crank and rods) Heads are cast similar, but slightly different. Smaller valves on the 304 due to shrouding of the cylinder wall on bigger ones. Putting an SP2P intake and an Edelbrock carb is what I would do (planning that on the 290 I'm putting in my '82 Honcho) > CC: fsj-at-digest.net > From: ltesar3421-at-sbcglobal.net > Subject: Re: fsj: 304 vs Stroker 6 > Date: Fri, 28 Jan 2011 23:07:21 -0600 > To: ltesar3421-at-sbcglobal.net > > Woops, check the math on that, 304/8 = 38 cu in/cyl. > ////// > On Jan 28, 2011, at 10:42 PM, Kim Tesar wrote: > > > Hi all, > > > > Jim, I remember you suggested considering a 304 as a replacement in > > the J10, instead of a stroker 6 build. > > > > This has got to have some merit. > > > > It seems most people spend time trying to get these motors to > > breathe. The sixes and eights have the same size valves, > > 1.94/1.5. Good stroker builds show about 265 hp, maybe 290 lb-ft, > > but the sixes have the longer stroke. Which have to move slightly > > more air per cylinder: 360/8 = 45 cu in,, 282/6 = 47 cu in > > (stroker 4.6) > > > > Getting bigger valves in a 6 cyl head, there are some on ebay with > > raised ports and beautiful machining for $1600, um, I don't think > > so. And by the time you're at that level, you're thinking roller > > cam = $1100. This is starting to get silly. > > > > The 304 must be more efficient at moving air, right out of the box, > > if it uses the same heads as the 360 with an undersquare bore/ > > stroke ratio... 304/8 = 32.5 cu in per cylinder. And you get the > > cross flow head with better intake runner design, and more cubic > > inches out of the box than the stroker. Less money would need to > > be invested in head work to improve the flow relative to the size > > of the motor. > > > > There's a 304 on Craigslist in San Antonio for sale, in good shape, > > for 800, maybe that's a better go. > > Any other thoughts on this? > > > > - Landon ------------------------------ Date: Sat, 29 Jan 2011 00:53:13 -0600 From: Kim Tesar Subject: Re: fsj: 304 vs Stroker 6 vs 360 Thanks, Mark. I have to ask myself, what's the point? The point is to have a reliable, mild build that's very streetable, with good mileage and fair power, that is efficient, and easy to maintain. Now I see the 360 has a better bore/stroke ratio than the 304. And the 360 and 304 stock heads are different, and you can't just throw the 360 heads on without resizing exhaust valves and shaving the heads to help compression. I was looking for some magic combination for a 304 that would line up with the overall design, but I'm not hearing one. Good to hear about safely raising the compression target on the v8. The six needs dished pistons, and don't even bring them to the deck to keep compression under 10:1. Maybe the six, with a 4.0 head, nicely rebuilt, is the ticket. Towing up to 2500 lbs, trailer included, is in scope, but otherwise, just comfortable street performance is the target. - - Landon On Jan 28, 2011, at 11:58 PM, Mark Wallace wrote: > Landon - > > The 1972 and later AMC 304, 360, 401 heads will flow better than > the "Camel > Hump" Corvette heads that were the holy grail of the Bow Tie set > right up > until aluminum aftermarket heads became affordable to the masses. > That being > said you can get a big cam, big valves, big carburetor, big > manifold, big > headers, big exhaust but without port work a lot of what you are > doing is > opening up the big end of the funnel. That being said with 235/75 > 15 tires and > a 3.31 gear the engine is winding about 3000 rpm at 75 mph. Port > work and big > valves and big cams are really more for high revs. Not that I > wouldn't do port > work on a no expense spared engine for a my Wagoneer. > > If I were building any engine be it for a Sport car (got one of > them) a work > horse pickup (got one of them too) or a Full Size Jeep I would bump > the > compression up. I don't think I would go any lower than 10:1. AMC > V8's are > apparently tolerant of going quite a bit higher. Don't know about > the sixes. > Too much higher and you also need to get into stuff like forged > rods, forged > crank, and forged pistons. Big torque comes from big compression. > > If you are looking at the V8 route I'd look into a salvage yard > 360. If you > can start it and see that it has good compression, good oil > pressure and no > rod knock even better. When I lived in New England you could buy > rusted out > Wagoneers all day long with good engines for $400 or less. I > suspect that you > could get your $400 back on the ebay. (my last parts car turned me > a profit) > You might take a look at what's out near the sea in Texas. I can check > Albuquerque yards for you. > > I have a built 360 that I have really enjoyed. It's plenty powerful > enough to > pull a sports car on a trailer. I am pretty sure I have had 6000 > lbs behind it > for a long highway run. It's big downside is just how thirsty it > is. I built > it in the summer of 1995 and there are things I would do > differently if i were > building it today (like more compression) but it's been a great > engine over > the years. > > Mark Wallace > 81 Wag ------------------------------ Date: Sun, 30 Jan 2011 19:40:52 -0500 From: Mark Wallace Subject: fsj: Freeze plugs and front clip. Today was warm enough to wake the Wagoneer up and take it around the house a few times. (I am still driving with a gas can as my gas tank and borrowing the battery out of the Dakota) so we are not quite ready for real driving. Anyway I discovered that the freeze plugs in my cylinder heads were leaking. It looks like they are the steel freeze plugs and they have rusted out. So does anybody have any experience with replacing these freeze plugs? It doesn't look like access is great. The next question is how many hours to pull the whole front clip? Pulling the front clip may get me better access to the heads and will be required to replace the rocker panels anyway. Alternately I can pull the engine and transmission which would allow me to do some more sandblasting and painting on the frame as well as replacing the rest of the brake pipes and detailing the engine. Or do I just go down the slippery slope and pull the drivetrain and the clip and go crazy with the welder and the sandblaster and the paint gun? Mark Wallace 81 Wag ------------------------------ End of fsj-digest V1 #3694 **************************