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Magnum 360 stroker questions #2737900 01/29/20 10:22 PM 01/29/20 10:22 PM
Joined: Dec 2004 Posts: 10,551 Rittman Ohio fourgearsavoy OP I Live Here
fourgearsavoy OP I Live Here Joined: Dec 2004 Posts: 10,551 Rittman Ohio	I'm helping a friend rebuild his smallblock and it needs pistons so we were thinking of getting a stroker kit for it. I am not sure what the difference between a Magnum and an LA 360 is as far as rotating assembly goes. I have done some research here and most of the information is 5-10 years old. I did find that people advised to stay away from the Eagle cast crank but the Scat parts are good. Is there any new information out there on 360 Magnum stoker kits? I would like to know who has the good stuff and who to buy it from. There is a company called Clegg that seems to have a good rep for engine parts anybody ever deal with them? Thanks Gus 64 Plymouth Savoy 493 Indy EZ's by Nick at Compu-Flow 5-Speed Richmond faceplate Liberty box Dana 60

Re: Magnum 360 stroker questions [Re: fourgearsavoy] #2737998 01/30/20 09:24 AM 01/30/20 09:24 AM
Joined: Jan 2014 Posts: 36 PA O Ody1003 member
Ody1003 member O Joined: Jan 2014 Posts: 36 PA	Be aware, true 5.9 magnum blocks have a deck height (factory) that is approximately 0.015 shorter than an LA block. By the time you get them square decked, with on shelf piston compression heights with stroker kits you will need to machine the flat on the piston .010/.015 to get to 0.00 deck height. Lots of factory variance, you have to check this!

Re: Magnum 360 stroker questions [Re: Ody1003] #2738002 01/30/20 09:41 AM 01/30/20 09:41 AM
Joined: Feb 2005 Posts: 982 western pennsylvania b1dartsport super stock
b1dartsport super stock Joined: Feb 2005 Posts: 982 western pennsylvania	I know you are considering rebuilding your friends engine. I am doing the same for a buddy of mine. We found this offer from ATK Engines and after looking at the quality of the forged parts and the free shipping on this shortblock, at this price we thought it is sort of a no brainer. Here is a link: https://www.high-performance-engines.com/product-p/sp57.htm Last edited by b1dartsport; 02/06/20 09:15 AM.

Re: Magnum 360 stroker questions [Re: Ody1003] #2738003 01/30/20 09:45 AM 01/30/20 09:45 AM
Joined: Sep 2007 Posts: 1,890 Spahn Ranch RMCHRGR top fuel
RMCHRGR top fuel Joined: Sep 2007 Posts: 1,890 Spahn Ranch	Check the link below, some good info there. The guy who made the webpage was a member on FABO for a while, maybe here too. His Dart was quick for what it was. http://www.magnumswap.com/ '71 Duster '17 Ram 1500

Re: Magnum 360 stroker questions [Re: RMCHRGR] #2738009 01/30/20 09:58 AM 01/30/20 09:58 AM
Joined: Sep 2007 Posts: 1,890 Spahn Ranch RMCHRGR top fuel
RMCHRGR top fuel Joined: Sep 2007 Posts: 1,890 Spahn Ranch	What type of build up is it going to be? Budget or...? The factory stuff is pretty stout so if its just for street you can probably re-use whatever is viable beyond the rotating assembly. There are inexpensive stroker kits available from anywhere though - Hughes, Mancini, Marsh, Indy, Summit, etc. If you go with new iron heads the EQ are hard to beat but not sure they are available anymore? Edelbrock makes Magnum-specific heads, or at least they used to. '71 Duster '17 Ram 1500

Re: Magnum 360 stroker questions [Re: fourgearsavoy] #2738011 01/30/20 10:05 AM 01/30/20 10:05 AM
Joined: Jun 2018 Posts: 350 Mequon, WI G gzig5 enthusiast
gzig5 enthusiast G Joined: Jun 2018 Posts: 350 Mequon, WI	My understanding is the the stroker kits are the same for LA or Magnum. Most people are very happy with the Scat cast crank kits for builds up to about 500-550hp. Not familiar with Clegg.

Re: Magnum 360 stroker questions [Re: RMCHRGR] #2738018 01/30/20 10:15 AM 01/30/20 10:15 AM
Joined: Oct 2010 Posts: 46 Can. H Hellrico505 member
Hellrico505 member H Joined: Oct 2010 Posts: 46 Can.	Hi, I order stroker kit thru Clegg website. They called me 10 minutes later to chat a little bit(block, hone, line hone, deck height, compression, etc.) about the built in general. I had my mesurement done so, I was confortable with the conversation. I appreciate the call. As a note, engine is assemble, went well. Not fire up yet.

Re: Magnum 360 stroker questions [Re: Hellrico505] #2738986 02/02/20 12:13 PM 02/02/20 12:13 PM
Joined: Dec 2004 Posts: 10,551 Rittman Ohio fourgearsavoy OP I Live Here
fourgearsavoy OP I Live Here Joined: Dec 2004 Posts: 10,551 Rittman Ohio	Thanks a lot guys for the tips it seems there is enough different things about the Magnum I better get a book about them. I have talked to a local Mopar engine builder and he told me they run really strong but the factory Magnum heads are a little too small for a 408 engine to make good power. The Edelbrock Magnum heads are designed to use small block Chevy which is a plus because you can get a decent set of rockers without spending $600-800. My buddy wants to get into the low 12's or high 11's with a smallblock in a 71 Road Runner and from what I've been reading it's possible with a 408 and some good heads. Gus 64 Plymouth Savoy 493 Indy EZ's by Nick at Compu-Flow 5-Speed Richmond faceplate Liberty box Dana 60

Re: Magnum 360 stroker questions [Re: fourgearsavoy] #2739180 02/02/20 09:35 PM 02/02/20 09:35 PM
Joined: Mar 2003 Posts: 2,491 PA moparacer top fuel
moparacer top fuel Joined: Mar 2003 Posts: 2,491 PA	I have a 402 cid magnum engine in a 67 Barracuda with cleaned up stock heads that runs 11.20s with a mild hydraulic roller cam and 3.55 gears in it so you can definitely get high 11's in a Road runner I bet. You will be RPM limited with the heads though. I shift at 5800 and cross at 5800. With a set of good aftermarket heads and more gear mine would run high 10's easy. 67 Barracuda street/bracket car 11.27-119 68 Dart 502 BB 8.70s-152 414 cid SB Dragster 7.65-174

Re: Magnum 360 stroker questions [Re: fourgearsavoy] #2739229 02/03/20 01:38 AM 02/03/20 01:38 AM
Joined: Jan 2003 Posts: 1,908 Nebraska 4 4406bbl top fuel
4406bbl top fuel 4 Joined: Jan 2003 Posts: 1,908 Nebraska	I just did a 408 with an eagle balanced steel crank-hbeam-mahle piston kit and the pistons ended up between .003 and .005 in the hole... block was that straight. With the eddy 58cc ( measured) heads, and a .036 cometic gasket it has 9.84 compression. The pistons and head cc are the big difference between la and magnum, make sure you get what compression you want, the blocks are shorter so an la non dished piston and magnum head could get you 12.00 compression.

Re: Magnum 360 stroker questions [Re: 4406bbl] #2739347 02/03/20 02:28 PM 02/03/20 02:28 PM
Joined: Mar 2005 Posts: 403 Colorado front range B BcudaChris mopar
BcudaChris mopar B Joined: Mar 2005 Posts: 403 Colorado front range	Used a 4" Clegg kit in my 5.9/406. Couldn't be happier with the service or the products (SCAT rods/crank, King brgs, Icon slugs and total seal rings). I did receive a damaged main shell and the guy had a new box of brg's overnighted to me from a 3rd party. supplier. All machining was spot on. I had Clegg do the balance as well and it was spot on. Machining quality superiority of the Magnum block over the LA was a nice surprise for my budget. Very satisfied with my finished product and Clegg is a quality supplier I would use again.

Re: Magnum 360 stroker questions [Re: BcudaChris] #2739434 02/03/20 09:12 PM 02/03/20 09:12 PM
Joined: Aug 2006 Posts: 2,141 junction city oregon V viperblue72 top fuel
viperblue72 top fuel V Joined: Aug 2006 Posts: 2,141 junction city oregon	I used a scat cast kit with forged icon pistons and they ended up .020 out of the hole. Not sure why or how but I just used a .070 head gasket and problem solved.

Re: Magnum 360 stroker questions [Re: viperblue72] #2739513 02/04/20 01:14 AM 02/04/20 01:14 AM
Joined: Jan 2003 Posts: 3,122 Auburn WA Dave_J master
Dave_J master Joined: Jan 2003 Posts: 3,122 Auburn WA	The ATK 410 5.9 Magnum short block has 4.040" KB pistons, Scat 4 inch cast crank, Scat I beam rods. Pistons are D dished and the quench shelf is positive above the deck. I have not measured it yet. I will be doing 'Clay' testing when I put the heads on. For $2500 it is a well thought out hunk of iron. The compression will be around 10.2:1 with the Edelbrock aluminum heads. Retired, US ARMY 1973-1994 ASE mechanic, Electrical 1994-1997 Retired GTE/VERIZON/FRONTIER 1997-2015 Posting cheap tech help (CRAP) here since Nov 97, 1000's of posts, some may be good. 03 Suzuki Burgman 650(Burger King) Scooter 65 Formula S Cuda 78 Little Red Express Truck 98 Buick Regal (wifes car)

Re: Magnum 360 stroker questions [Re: fourgearsavoy] #2739615 02/04/20 12:25 PM 02/04/20 12:25 PM
Joined: Jan 2003 Posts: 1,908 Nebraska 4 4406bbl top fuel
4406bbl top fuel 4 Joined: Jan 2003 Posts: 1,908 Nebraska	Originally Posted by fourgearsavoy I'm helping a friend rebuild his smallblock and it needs pistons so we were thinking of getting a stroker kit for it. I am not sure what the difference between a Magnum and an LA 360 is as far as rotating assembly goes. I have done some research here and most of the information is 5-10 years old. I did find that people advised to stay away from the Eagle cast crank but the Scat parts are good. Is there any new information out there on 360 Magnum stoker kits? I would like to know who has the good stuff and who to buy it from. There is a company called Clegg that seems to have a good rep for engine parts anybody ever deal with them? Thanks Gus What I would do is get the heads he wants, cc them, put them on the block to see if they and the intake fit, and determine how much milling you can do to fix the compression if you get the wrong piston in a kit. My edlbrocks are 58cc exact, others have reported some as high as 62. What little I have messed with the magnum the 1.46 compression height piston will be .005ish in the hole, Icon makes a magnum head piston at 1.465 ch, with valve reliefs, but compression is 13.5. My pistons are 1.46 ch, 28cc dish, 9.84 to 1, after a .010-.015 head mill it will be 10-1. My block is almost mirror deck finish, but the heads are rough, not confident the cometic gaskets will seal, only reason to mill them. Nobody around here can do much less than .010. Your biggest issue is getting the compression right, so pick a head and piston first and mock the block up, that way you are not milling the block, unless it is crooked, doubtful on a magnum, then the pistons, then the heads, that wastes$$$. I never buy anything internal till I put the heads and intake on and cc the heads anymore, I have learned. The only other issue is h-beam mopar rods need an eyebrow bore notch, I am told if you order the kit with chevy journals it does not. Plenty of pistons out there just do your math.

Re: Magnum 360 stroker questions [Re: 4406bbl] #2739831 02/05/20 01:36 AM 02/05/20 01:36 AM
Joined: Jan 2003 Posts: 3,122 Auburn WA Dave_J master
Dave_J master Joined: Jan 2003 Posts: 3,122 Auburn WA	Originally Posted by 4406bbl What I would do is get the heads he wants, cc them, put them on the block to see if they and the intake fit, and determine how much milling you can do to fix the compression if you get the wrong piston in a kit. My edlbrocks are 58cc exact, others have reported some as high as 62. What little I have messed with the magnum the 1.46 compression height piston will be .005ish in the hole, Icon makes a magnum head piston at 1.465 ch, with valve reliefs, but compression is 13.5. My pistons are 1.46 ch, 28cc dish, 9.84 to 1, after a .010-.015 head mill it will be 10-1. My block is almost mirror deck finish, but the heads are rough, not confident the cometic gaskets will seal, only reason to mill them. Nobody around here can do much less than .010. Your biggest issue is getting the compression right, so pick a head and piston first and mock the block up, that way you are not milling the block, unless it is crooked, doubtful on a magnum, then the pistons, then the heads, that wastes$$$. I never buy anything internal till I put the heads and intake on and cc the heads anymore, I have learned. The only other issue is h-beam mopar rods need an eyebrow bore notch, I am told if you order the kit with chevy journals it does not. Plenty of pistons out there just do your math. If you get the 4 inch stroke Scat Crank and Scat PRO SERIES I-BEAMS rods it clears the block, NO GRINDING. These rods have smaller bolt heads with no nut. Retired, US ARMY 1973-1994 ASE mechanic, Electrical 1994-1997 Retired GTE/VERIZON/FRONTIER 1997-2015 Posting cheap tech help (CRAP) here since Nov 97, 1000's of posts, some may be good. 03 Suzuki Burgman 650(Burger King) Scooter 65 Formula S Cuda 78 Little Red Express Truck 98 Buick Regal (wifes car)

Re: Magnum 360 stroker questions [Re: Dave_J] #2739998 02/05/20 02:45 PM 02/05/20 02:45 PM
Joined: Mar 2005 Posts: 403 Colorado front range B BcudaChris mopar
BcudaChris mopar B Joined: Mar 2005 Posts: 403 Colorado front range	Originally Posted by Dave_J For $2500 it is a well thought out hunk of iron. The compression will be around 10.2:1 with the Edelbrock aluminum heads. For sure, and I landed at the same measured static compression. EQ heads and the chambers ended up at 69cc. Originally Posted by Dave_J If you get the 4 inch stroke Scat Crank and Scat PRO SERIES I-BEAMS rods it clears the block, NO GRINDING. These rods have smaller bolt heads with no nut. Yeah, had my block at the machine shop and notched before my kit arrived. My research and questions failed me on this item. On the plus side though, the block is ready for a longer arm if I'm so inclined. Last edited by BcudaChris; 02/05/20 02:46 PM. Reason: to coverup borderline illitaracy

Re: Magnum 360 stroker questions [Re: BcudaChris] #2740187 02/06/20 12:01 AM 02/06/20 12:01 AM
Joined: Dec 2004 Posts: 10,551 Rittman Ohio fourgearsavoy OP I Live Here
fourgearsavoy OP I Live Here Joined: Dec 2004 Posts: 10,551 Rittman Ohio	Well some real world information here that I was looking for. My buddy decided on an Eagle forged crank and Eagle rods with Diamond dished pistons designed for the Magnum engine. It was more expensive than a "kit" but he was thinking of maybe hitting it with some spray in the future so I know the forged Eagle crank will be good. The block will be at the machine shop for a while so it's going to be a few weeks until we get it back. Decided to go with the factory heads and just clean up the bowls and smooth out the pinch Going with a mild cam with some good torque to get the B-body rolling. Thanks again for all the insight and information Gus 64 Plymouth Savoy 493 Indy EZ's by Nick at Compu-Flow 5-Speed Richmond faceplate Liberty box Dana 60

Re: Magnum 360 stroker questions [Re: Dave_J] #2740221 02/06/20 08:45 AM 02/06/20 08:45 AM
Joined: Mar 2006 Posts: 9,813 MI, usa dvw master
dvw master Joined: Mar 2006 Posts: 9,813 MI, usa	the heads are rough, not confident the cometic gaskets will seal, only reason to mill them. Nobody around here can do much less than .010. [/quote] You need to find a real machinist. Weve skim cut heads .002" without issue. Doug

Re: Magnum 360 stroker questions [Re: dvw] #2740423 02/06/20 05:13 PM 02/06/20 05:13 PM
Joined: Jan 2003 Posts: 3,122 Auburn WA Dave_J master
Dave_J master Joined: Jan 2003 Posts: 3,122 Auburn WA	Originally Posted by dvw the heads are rough, not confident the cometic gaskets will seal, only reason to mill them. Nobody around here can do much less than .010. You need to find a real machinist. We've skim cut heads .002" without issue. Doug [/quote] +1 When I had my 318 block decked they did a 'KISS' cut at 0.002" and it only touched in 3 places. They had to do 0.010 before it was even close to fresh metal. It took 0.020" to equalize both decks so not too bad and I had a total of 0.030" taken. So yes they CAN do 0.002" if they are not lazy. But will 0.002" clean up the surface in 1 wack? Retired, US ARMY 1973-1994 ASE mechanic, Electrical 1994-1997 Retired GTE/VERIZON/FRONTIER 1997-2015 Posting cheap tech help (CRAP) here since Nov 97, 1000's of posts, some may be good. 03 Suzuki Burgman 650(Burger King) Scooter 65 Formula S Cuda 78 Little Red Express Truck 98 Buick Regal (wifes car)

Re: Magnum 360 stroker questions [Re: Dave_J] #2770229 05/01/20 06:23 PM 05/01/20 06:23 PM
Joined: Dec 2004 Posts: 10,551 Rittman Ohio fourgearsavoy OP I Live Here
fourgearsavoy OP I Live Here Joined: Dec 2004 Posts: 10,551 Rittman Ohio	Well the owner decided on the Edelbrock heads and I found a cam that I think should work good for this mainly street car. It's a Howard's hydraulic roller Lift: .507 / .533, Duration @ .050: 221 / 225, Centerline: 108, Mild idle, Street performance, Big low end torque, Should have 9.0:1+ compression & 1800+ stall converter. It should make plenty of steam to push his car in the low 12 high 11's Gus 64 Plymouth Savoy 493 Indy EZ's by Nick at Compu-Flow 5-Speed Richmond faceplate Liberty box Dana 60

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