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Mild 341 build Jump to page : 1 Now viewing page 1 [50 messages per page] | View previous thread :: View next thread |
Forward Look Technical Discussions -> The Exhaust Pipe - Modification & Performance | Message format |
hecksheads |
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Regular Posts: 59 Location: N.W. FL | Finally getting around to rebuilding my 341. It's a slow process as I'm on a pretty tight budget plus other stuff always seems to require my time. I want a little more performance than stock, nothing to radical. I'll be doing some mods that may or may not work out. This will be going back in my '57 Desoto sedan which will remain otherwise stock appearing. I love threads of engine builds with pictures so I guess it's my duty to share mine. Block bored .030" over. Cylinders 5&7 had to be sleeved because of cracks in wall, probably frozen water in coolant passages at some point. Machine shop had installed freeze plugs and galley plugs so I pulled all those and cleaned block thoroughly. Crank is standard mains and rod, just polished the journals by hand a little, checked out OK with plastigage. Timing chain is Summit double roller for an LA. Pistons and rods installed. Oil pump was good, I disassembled, cleaned and shimmed the spring. Freeze plugs are big block brass plugs with a little epoxy. | ||
57desoto |
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Expert Posts: 1488 Location: New Castle PA | Love to see DeSoto engine innards. Keep the pics coming, Franklin! | ||
ttotired |
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Expert 5K+ Posts: 8443 Location: Perth Australia | I was looking at the freeze plugs Did you remove the ridge thats cast into the block, so those ones would fit? | ||
hecksheads |
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Regular Posts: 59 Location: N.W. FL | I cleaned up the holes for the freeze plugs with a die grinder, didn't take much. Pistons are cast replacements off ebay. Block deck was cut down .030" or .050" I can't remember which. Anyway pistons stick .024" out of block to achieve 10.0 to 1 comp. ratio. I had to enlarge the valve reliefs with a die grinder for piston to valve clearance. A slight chamfer was needed on the pistons for head clearance. Also the pistons were about 20 grams heavier than the originals so I ended up taking it off the skirts to balance. Pins were 6 grams heavier so I reused the originals. Small block LA timing chain. I will also be using LA timing chain cover so you might notice that water inlet holes have been moved. Four of the mounting bolt holes are the same, others need to be drilled and tapped. | ||
Mopar1 |
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Expert Posts: 3027 Location: N.W. Fla. | Hopefully the decking didn't throw off the valve train geometry, better to buy pistons in the C/R you want. | ||
GregCon |
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Expert Posts: 2524 Location: Houston | ....Either you are an excellent machinist with years of experience and lots of high quality precision tools, or you are doing some screwy stuff. You removed material from the skirts? You re-used old pins on account of 6 grams? You used a die grinder to modify the valve notches? Wow. I'm voting for #2 (screwy stuff). | ||
Shep |
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Expert Posts: 3393 Location: Chestertown, NY ( near Lake George) | I could see cleaning up the valve reliefs carefully then rechecking piston to valve clearances, but I never saw weight removed from a piston skirt, the normal way to balance pistons is to take material from the lower part of the pin boss. | ||
hecksheads |
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Regular Posts: 59 Location: N.W. FL | Well I wouldn't call myself a excellent machinist but I do have years of experience doing some screwy stuff! But really there's plenty of material on this area of the pistons, they have deep skirts. If you look at some of the pistons for stroker applications they have almost no skirt at all. These are cast pistons and I wouldn't want to weaken them by removing any material from the boss area. As for decking the block, this is a perfectly acceptable way of raising comp ratio and I will be using adjustable pushrods so valvetrain geometry is not an issue. | ||
Mopar1 |
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Expert Posts: 3027 Location: N.W. Fla. | hecksheads - 2014-08-07 6:49 PM That is debatable...... As for decking the block, this is a perfectly acceptable way of raising comp ratio | ||
60 dart |
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Expert 5K+ Posts: 8947 Location: WHEELING,WV.>>>HOME OF WWVA | if you take too much off the skirts to balance , you'll end up with piston slap -----------------------------------------------later Edited by 60 dart 2014-08-08 12:22 AM | ||
hecksheads |
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Regular Posts: 59 Location: N.W. FL | Small block LA timing cover and water pump installed. Balancer is a CAT fluid damper for small block Mopar. Oil pan buttoned up. | ||
hecksheads |
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Regular Posts: 59 Location: N.W. FL | Paint, Rustoleum semi-gloss applied with a brush. | ||
hecksheads |
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Regular Posts: 59 Location: N.W. FL | Heads, Machine work included having bronze guides installed, valve seats cut for oversized valves and resurfacing. Porting I did myself, around eight hours worth. On the intake ports most of the work was in the bowl area where I opened them up to the new valve size. I cut down the guide a bit and streamlined. In the transition area I opened them as much as I dared without breaking into the pushrod holes. The runners were widened and the roof raised a bit. The floor I left alone. On the exhaust side all I did was cut the guide boss down as these Hemi's flow well on the exhaust. Valves are small block Mopar 2.02" intakes and 1.78" on the exhaust. | ||
Mopar1 |
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Expert Posts: 3027 Location: N.W. Fla. | Considering the rep Desoto heads have for cracking I think I'd a left the valves OEM size.... | ||
hecksheads |
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Regular Posts: 59 Location: N.W. FL | You're right, they do have a tendency to develop cracks but the seats were recessed so I went with larger valves instead of new seats. Either way I had to replace the valves and this way I pick up some flow. | ||
hecksheads |
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Regular Posts: 59 Location: N.W. FL | Heads installed, Valve springs are single with damper from Trick Flow Specialties, retainers are stock, keepers are Crane single groove, pushrods and Hyd. lifters came from Hot Heads. Cam is reground from Oregon cam grinding. Cam specs: Duration @ .050" 223/223 Lift .470"/.470" LSA 110* Installed advanced 4 degrees | ||
60 Imp |
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Location: North Australia | Engine is looking the goods, good luck with the build. Hope to hear how it runs, and soon by the looks! Steve. | ||
tnlowrider |
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Extreme Veteran Posts: 500 Location: Upper East Tennessee | Awesome! I really like what you did with the timing cover and water pump. | ||
tnlowrider |
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Extreme Veteran Posts: 500 Location: Upper East Tennessee | Awesome! I really like what you did with the timing cover and water pump. | ||
hecksheads |
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Regular Posts: 59 Location: N.W. FL | Turned a Firedome two barrel intake into a 4 barrel intake. Rough cut I used an aluminum carb spacer as my mounting pad. Finished | ||
Mopar1 |
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Expert Posts: 3027 Location: N.W. Fla. | Looking good! | ||
ttotired |
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Expert 5K+ Posts: 8443 Location: Perth Australia | How did you seal the mounting plate to the manifold? I looks like it wasnt machined in the top picture Did you use a liquid metal (epoxy) type of product? (1.jpg) Attachments ---------------- 1.jpg (6KB - 288 downloads) | ||
hecksheads |
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Regular Posts: 59 Location: N.W. FL | It doesn't look like it in the top picture but I actually got a fairly level surface first with a belt sander then a hand file. I used two gaskets under the adapter to be sure it sealed. | ||
ttotired |
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Expert 5K+ Posts: 8443 Location: Perth Australia | That must have taken ages | ||
Brushwolf |
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Veteran Posts: 292 Location: Twin Cities MN | Very interesting build, especially since i have a 341 and a 330 DeSoto motor awaiting rebuild too. Will build whichever block checks out better at machine shop, since heads and rotating assemblies are the same. My 341 did have a cracked head, but have since picked up a replacement pair, plus the 330 heads look ok too. Waiting to get my 348 W motor back from shop before bringing the DeSoto motor in though. Good timing that you happen to be doing this one now. What all is involved in making the Mopar timing cover fit? Will Mopar small block fuel pump bolt up correctly then w/o any forther mods? I had heard those intakes could be modified but had not seen it done before. Looks like alot of work as mentioned, but it turned out well. | ||
Mopar1 |
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Expert Posts: 3027 Location: N.W. Fla. | Think I heard the guy in New Zealand may be getting close to getting his act together on the high deck intakes. | ||
hecksheads |
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Regular Posts: 59 Location: N.W. FL | I thought Hot Heads had tall deck Desoto aluminum intakes. Anyway I can't afford one right now. I'm saving my money for a trans adapter. | ||
hecksheads |
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Regular Posts: 59 Location: N.W. FL | Engine installed with trans adapter and A518 | ||
60 Imp |
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Location: North Australia | Thanks for the update. I also like the engine build threads. I am keen to see the result of your efforts, I see lots of dedication in the pics Mate! I predict you will get many questions on the exhaust. The undercarriage pic is very cool. Looks interesting. Nice work. Steve. Edited by 60 Imp 2016-12-07 6:58 AM | ||
Powerflite |
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Expert 5K+ Posts: 9604 Location: So. Cal | You got that right about the exhaust. Can you show a picture of the headers off the car? Great work on them. I also really like the 4bbl intake conversion. I may do something similar with the 331 hemi truck wet intake that I have. | ||
56D500boy |
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Expert 5K+ Posts: 9855 Location: Lower Mainland BC | Powerflite - 2016-12-07 1:11 PM I also really like the 4bbl intake conversion. I may do something similar with the 331 hemi truck wet intake that I have. Agree. And that raises a question: Which hemi intake manifolds have the carburetor heated by exhaust and which ones are heated with engine coolant. I thought my 315 D500 hemi intake was heated with coolant but the mechanic that set up the carb last week said it was exhaust (I think he was wrong - probably the only 315 hemi that he has ever seen). How could I tell? Or should it be obvious and I am just missing it? | ||
wayfarer |
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Elite Veteran Posts: 888 Location: Peoples Republic of Oregon | AFAIK, the only intakes with coolant under the carb are the Chrysler units used in trucks and marine applications. The easy way to tell what you have is to look at the passage....exhaust heat will have left plenty of carbon deposits, and since you have a Dodge it will be exhaust. | ||
hecksheads |
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Regular Posts: 59 Location: N.W. FL | I made the headers with a weld-up kit that cost a hundred bucks from Summit. 1 3/4" aluminized tube. The 3/8" flanges I got on ebay, $55. A lot of cutting, welding and grinding and my welding skills are not the greatest but they turned out pretty well. Passenger side was really no problem, only the oil filter to work around. Drivers side is tight between the torsion bar and steering box. I'm going to run a power steering cooler along with synthetic fluid. | ||
Powerflite |
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Expert 5K+ Posts: 9604 Location: So. Cal | Sweet. Thanks for sharing. They look like what I imagined they would be, kinda flattened out to get between the frame and T-bar, and then re-grouped. I have made a set of headers myself so I know they are a lot harder to make than it looks. Good job! Hard to see, but it doesn't look like they are too close to the steering box from this angle. | ||
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