Help with custom cam for 418 LA stroker
#889657
12/27/10 03:01 PM
12/27/10 03:01 PM
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Joined: Jul 2006
Posts: 383 Essex, Ont., Canada
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I need a little help choosing a custom hydraulic roller for my .040" over, 4" crank, 340 street/strip engine. Here's the basics: Callies forged crank, Eagle H-beams, Diamond 23cc dished pistons, ported Edelbrock RPM heads with sleeved push rod pinch and head bolt bulge (not sure of flow #s yet), Edelbrock Air Gap intake, port matched and a holley 950 street HP carb. Block is zero decked with .040" quench and a true 10.5 to 1 compression. This engine will breath through 1 7/8" TTI headers and a 2.5" exhaust with X-pipe and dumps. I have 1.6 to 1 Harland Sharp rockers and new Hughes hydraulic roller lifters. The engine is going into my barebones, 4 speed, 1972 cuda with a 4.10 8 3/4 rear and 275 60R-15 tires. I've decide on Comp Cams XFI lobes; lobe #3018 on the intake, which is .242 @ .050 and .584" lift with the 1.6 rockers. My dilemma is choosing between a straight or split pattern, lobe# 3038 .242 @ .050 with .576" lift or lobe# 3039 .248 @ .050 with .579" lift, on the exhaust. I do not care about idle quality or vacuum. Also, I want a tight LSA: 106, 107 or 108 degrees?? Sorry for the long post, just wanted to give all the info. Thanks!!
1972 Plymouth Cuda 340 4 speed
1971 Plymouth Road Runner 383 Auto
1970 Plymouth Duster /6 Auto
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Re: Help with custom cam for 418 LA stroker
[Re: hp340nos]
#889660
12/27/10 06:50 PM
12/27/10 06:50 PM
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Joined: Jan 2003
Posts: 4,002 Joplin, Mo
rt66jim
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Well if you don't care about idle quality. I would put about 20* more duration in it. Mine is 272@.050 and I have 4400 converter. It was streetable. with a stick you should have no problems and it will be an animal on the street. JMO Jim
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Re: Help with custom cam for 418 LA stroker
[Re: rt66jim]
#889661
12/27/10 06:57 PM
12/27/10 06:57 PM
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Joined: Feb 2003
Posts: 361 nj pine beach
dart9ss
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Call Dwayne! Porter racing heads, he will give you the best advise and can order the cam . my you won't be disapointed.
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Re: Help with custom cam for 418 LA stroker
[Re: dart9ss]
#889663
12/27/10 07:07 PM
12/27/10 07:07 PM
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I may well do that, but I would like to get the opinions of a few others as well. As for 20 degrees more duration, the engine will be more street than strip and I think I need to compromise a bit more for the street.
1972 Plymouth Cuda 340 4 speed
1971 Plymouth Road Runner 383 Auto
1970 Plymouth Duster /6 Auto
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Re: Help with custom cam for 418 LA stroker
[Re: dynamite]
#889664
12/27/10 07:10 PM
12/27/10 07:10 PM
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Joined: Mar 2005
Posts: 331 Cincinnati Oh
fasthawk6
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Quote:
Do your self a favor and talk to an expert..Call Tim at Bullit cams ,,he's done a ton of small block cams ,,Knows his stuff..662-893-8022
Got one in my 408
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Re: Help with custom cam for 418 LA stroker
[Re: emarine01]
#889666
12/27/10 07:32 PM
12/27/10 07:32 PM
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I've done numerous searches and that is how i've come up with what i've got so far. Just looking for something a little more specific for my build and intended use. Thanks
1972 Plymouth Cuda 340 4 speed
1971 Plymouth Road Runner 383 Auto
1970 Plymouth Duster /6 Auto
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Re: Help with custom cam for 418 LA stroker
[Re: Fishmarket]
#889667
12/28/10 12:17 AM
12/28/10 12:17 AM
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Joined: Nov 2004
Posts: 226 lino lakes,MN
onebaddakota
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I run a very similar combo. It's a 408 magnum 10.0 :1 compr, .ported magnum eddies, ported M1, 950HP carb, 1 3/4 headers.My hyd. roller is an XFI lobe 236/242 with .579 lift on a 108. It gives me 10" of vacuum. It's run a best of 10.90@ 121 I have a lean condition with my fuel system so I'm expecting a little more out of it this year.
10.56 at 125.6, with a 1.43 60 ft.
E85, Hyd. Roller 410 magnum,full exhaust, 3500 race weight.
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Re: Help with custom cam for 418 LA stroker
[Re: onebaddakota]
#889668
12/28/10 12:22 AM
12/28/10 12:22 AM
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Thanks onebad...Do you have any dyno #s for that engine? Do you know where your peak torque and hp are? When do you shift? Thanks again.
1972 Plymouth Cuda 340 4 speed
1971 Plymouth Road Runner 383 Auto
1970 Plymouth Duster /6 Auto
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Re: Help with custom cam for 418 LA stroker
[Re: dynamite]
#889670
12/28/10 11:36 AM
12/28/10 11:36 AM
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Joined: Nov 2009
Posts: 3,082 St. Paul , Mn.
tubtar
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Quote:
Do your self a favor and talk to an expert..Call Tim at Bullit cams ,,he's done a ton of small block cams ,,Knows his stuff..662-893-8022
This would be my advice. Make a call to someone who is an expert. Strokers love duration , so I think you might be leaving a little on the table here. My 405 will be a solid roller , but we settled on 268* @.050 and .668 lift with 1.6's. 106 LSA. And my heads will flow significantly more than yours. ( Ported W-9's ) He was for a little more separation and suggested 108 , but my motor will see limited street use and have a looser converter so after some discussion , this is what we decided to go with. It is a decision I would never make on my own , and though it is close to what I had in mind , it is more aggressive..........no dyno #'s yet , but I have high expectations. Having your flow numbers makes it much less of a guess too.
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Re: Help with custom cam for 418 LA stroker
[Re: tubtar]
#889671
12/28/10 12:24 PM
12/28/10 12:24 PM
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Joined: Jan 2003
Posts: 9,876 Weddington, N.C.
Streetwize
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Pretty close to my 414 build I have on the stand, just patiently waitng for Ryan at Shady Dell to work his Magic on my Eddies. For a mostly street motor to maximize your cam choice you really need to see the flow curve of the heads you are working with, you can 'ballpark' a cam but to really get it right we need the flow curve. I pay most attention to the mid (.200-.400) lifts as well as some of the ratios between the mid and peak lifts to set the ideal Intake centerlines and Intake closing events. With a 4 speed I'd be looking at a ported Victor 340 over an RPM, bottom end torque is not going to be an issue for you, not with those gears and a 4 speed. Also with a 4 speed in a port limited motor you MAY want to consider spreading out the lobe seperation (you have less rpm drop between gears than an automatic so you should want more gap between peak tq and peak HP rpm). I would say 108 would be minimum for your case, Tight centers and under ported equals limited RPM potential with a fast rising (but fast falling) torquer peak. Bottom line head flow determines your HP potential (assuming you have the induction to match)...and to some extent it also determines your max HP RPM so this is what you use to dial-in your intake duration. Both Tim and Dwayne are great choices for advise. If your motor is under-ported (let's say your heads only flow ~.265 @ .550) for 418 cubes you can go a little bigger on the lobe but spread the centers out to help the upper RPM breathing....but you see in this case the better flowing (up high), shorter runner Victor 340 is also going to help that out. Based on the 265 cfm ( which we'll assume pretty average for well worked home ported eddies) I would look at something around 248/252 @.050 on 108 and around .575 lift but put it in around 105, you could go bigger with more compression. Wih a Bullet cam you could go bigger and still have good torque but with Eddies and the RPM intake I doubt it would make any more power. Bullet has some very impressive HR lobes that rev a LOT quicker than the HR's of the past, great .200 up numbers that get fairly close (but not quite) to some of the more mild solid roller race grinds. I like to build the stroker shortblock for the broadest bottom to top torque and then put the best heads I'm willing to afford for the build on it, from there I use the cam specs to TUNE WHERE I want the torque and power peaks based on the gears, weight and stall I want to run.
Last edited by Streetwize; 12/28/10 12:37 PM.
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Re: Help with custom cam for 418 LA stroker
[Re: justinp61]
#889673
12/28/10 01:07 PM
12/28/10 01:07 PM
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Joined: Jan 2003
Posts: 9,876 Weddington, N.C.
Streetwize
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Quote:
I'd call Hughes Engines for a cam. IMHO your intake will hold you back, I have a street/strip 408 with a Hughes 260/264 flat solid, ported Edelbrocks, 10.9-1 compression with a Victor 340. It pulls hard everywhere, bottom or top, it's gone 6.57 on pump 93 in a 3260# 69 Dart with a 4.10 gear.
I've got 12:1 with pretty much the same combo as yours Justin. I just wanted to go easy 6.90's-1/8th in my little 2900 lb w/d Rocky with 4.56 gears!!
BTW....pretty sure Bullet grinds the HR's for Hughes, not sure about the solids. I think the 248/252 HR I called out would be VERY comparable in perfromance to Justin's 260/264 solid, looks like we're on the same page On the street I really am an HR convert, over the past few years they (bullet) have really closed the performance gap vs a solid flat tappet.
Last edited by Streetwize; 12/28/10 01:11 PM.
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Re: Help with custom cam for 418 LA stroker
[Re: justinp61]
#889675
12/28/10 01:52 PM
12/28/10 01:52 PM
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Hmmm, perhaps my question would have been better suited on the Q&A forum. This build will be mainly for the street with the occasional blast down the strip. Maybe a few times a year. I just figured that most of the knowledgeable, professional engine builders were on here. I'm not looking for a max effort here just a well thought out, reliable, streetable engine that can hold its own. On a related note, here is the dyno results of a similar build from Dulcich. One point more compression, an M1 and a 1050 quickfuel. RPM TORQUE HORSEPOWER 3200 491 299 3400 495 321 3600 496 340 3800 508 368 4000 509 388 4200 517 414 4400 522 438 4600 529 463 4800 532 486 4900 533 497 5000 532 506 5200 528 523 5400 522 537 5600 513 547 5800 501 553 6000 484 553 6100 477 554 6200 468 552 This is with a custom XFI hydraulic roller 236/236 @ .050 .576/.576 lift. Very stout numbers if you ask me and more than enough for a stock 2 bolt main block. I don't want to rev this thing to 7000 and as I said, it will see more street than strip. Please, don't get me wrong, I really appreciate everyone's input. My goal here is 500hp/500ftlbs. If I get 525/525 great, I would be very happy! Basically, I want to know if I should add duration on the exhaust, and what LSA would work best for my intended use.
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Re: Help with custom cam for 418 LA stroker
[Re: Fishmarket]
#889676
12/28/10 02:23 PM
12/28/10 02:23 PM
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Joined: Jan 2003
Posts: 9,876 Weddington, N.C.
Streetwize
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I was just on the Hughes site and wondering why all of their HR grinds are on 114? Their BB HR's are on the 'correct' 108 Bottom line fish is either cam you have should work well enough to hit 500/500, but I've run the Comp XE HRs and the Bullets and I like the Bullets better BY A BUNCH, I'll stand on my 248/252 call and I'm pretty sure Tim Goolsby's pick would be very close. FWIW...when you undercam a serious torque street stroker with a 4 speed you will have a very hard time getting and keeping it hooked on street tires...that's why I say it's important to get the torque curve where it'll do you the most good (ie, propelling the car) . Steve's 236/236 example would be perfect for a 3200-3400 stall automatic car but I'm thinking a 4 speed cuda with 4.10's would spin and spin and give up maybe 30-40hp up top once it did get hooked up. Guys that dyno all the time on here pretty much all say take the Westech HP/tq 'magazine' numbers with a big grain of salt, not taking anything away from ANYTHING my buddy Steve does. He's one of the few guys left in the Mag business that actually includes the USEABLE TECHNICAL INFORMATION in his articles.
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