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jeffb
Dodge Dakota
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10/24/2003
16:56:53
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 Subject: Crower 1.7 and M1 on a 318
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I'm getting ready to install an M1 and an F&B 50 MM TB. Got the M1 to get rid of the belly pan gasket and the TB for more hp. I understand that they will help top end but I have also heard from others that I may lose bottom end with the M1. I'm going to install it anyway (because I have it and why not) but I am also looking at Crower 1.7 RR. Will the Crowers add low end or improve torque that I may lose with M1? I'm sticking with the stock cams. I'm also concerned about towing. I don't tow a lot of things but occasionally I do.
I've got a 97 5.2 4x4 auto w/48,000 miles & K&N.
Thanks
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Shinnysideup
Dodge Dakota
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10/24/2003
17:02:56
|  RE: Crower 1.7 and M1 on a 318
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I have the 1.7 with stock cam, the rockers will pull harder from about 2500 rpm on up.
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jeffb
Dodge Dakota
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10/24/2003
17:19:03
| RE: Crower 1.7 and M1 on a 318
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Thanks - did you find that it was worth it? Sounds like it doesn't really help with low end torque that much?
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jeffb
Dodge Dakota
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10/24/2003
17:21:35
| RE: Crower 1.7 and M1 on a 318
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Sorry I mean it does help! right
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Shinnysideup
Dodge Dakota
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10/24/2003
18:15:30
| RE: Crower 1.7 and M1 on a 318
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It makes no differnce to the low end. Was it worth it ? I think so. Since then I have added a higher stall converter and a MP computor, the truck pulls way harder than before. And before anyone ask, No I have not dyno'ed it. Next on the list is a MP R/T cam and for now I am staying away from headers but I have exhaust manifolds from a 93 Dakota and a local muffler shop is going to fab a new y-pipe.
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rtdkota
R/T
 
10/24/2003
20:38:21
| RE: Crower 1.7 and M1 on a 318
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The 1.7s come on about 2500-2600 rpm-- pull good up to your stock peak hp of around 4600-4800 rpm.
The 5.2L has a hotter cam than the 5.9L, so you should see a good midrange improvement-- in the neighborhood of 12-15 rwhp, 15-20+ ft. lbs.
I've got them for sale on my website.
If you have a question, call or email me!
Sam
www.socaldakota.com
619-274-1292
www.socaldakota.com
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gen1dak
Dodge Dakota
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10/24/2003
23:25:02
| RE: Crower 1.7 and M1 on a 318
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The 1.7:1 rockers will speed up the opening and closing of the valves. While peak duration remains the same, the effective duration "under the curve" is increased slightly. The lift goes from, what is it, .432? The 1.7's make that .459. All of these factors shift the power range higher in the rpm range. Now, up to a certain point, a bigger cam will improve power over a stocker from near idle to redline, but the bigger you go, the further up the rpm "sweet spot" moves. The added lift should help, and the slightly hotter effective duration really won't hurt low-end, but, as has been stated, a looser converter and hotter computer help a lot too. Now the bad news. Stock valve springs are not good for much over .430 lift, so you may have valvetrain control issues if you push much above 5 grand. Might do fine at first, but they will fatigue quickly. Then you'll have valve float and there goes the power.
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rtdkota
R/T
10/25/2003
01:39:54
| RE: Crower 1.7 and M1 on a 318
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That's the nice thing with the 1.7s-- on a stock cam, your peak hp RPM increases not more than 200 rpm over stock...
Add an M1, and things move up a little more-- 5500 rpm is safe on the stock springs... I've done it consistantly up to 45k miles, and I have people running them for over 70k (float occurs between 5600-5800 rpm-)
SO, if you keep it below 5500 (for most that is plenty, as the truck is done making power well before that-- I peak out at 5450 even with my Crower custom cam and 1.92 RT heads)-- you should be fine with stock springs (though they are wimpy, there's no doubt in that).
Sam
www.socaldakota.com
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gen1dak
Dodge Dakota
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10/25/2003
20:38:57
| RE: Crower 1.7 and M1 on a 318
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It is not about what rpm you run. There are Magnum cams that will rev to 6000 rpm with the stock springs. It's about over-stressing a coil spring intended for a given amount of lift. People who shim their springs to meet a higher pressure requirement learn this lesson the hard way. It works for a while, but the springs stress and crack. Then you drop a valve and wipe out the cylinder. Increasing the rocker ratio increases the effective lift, which compresses the spring beyond the intended envelope.Ever heard of coil bind? Wiped cam lobes? Hey, you wanna roll the dice and risk it, be my guest. Save a little now, or a lot later.
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rtdkota
R/T
10/26/2003
01:20:01
| RE: Crower 1.7 and M1 on a 318
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"Ever heard of coil bind? Wiped cam lobes? Hey, you wanna roll the dice and risk it, be my guest. Save a little now, or a lot later."
I think you are barking up the wrong tree. The stock springs can handle .500 lift...The 1.7s on the stock cam put it in the .464 lift range. Coil bind won't happen below 5500 rpm-- Mopar Perf PCMs have 5200/5300 rpm shift point (and they wouldn't put a shift point within 200 rpm of bind-- they'd have more lawsuits than Philip Morris.)
Wiped cam lobes on a roller motor (hydralic)???
Again, Crower 1.7s on stock cam, stock springs-- 5500 rpm or below, you are fine. If you run above 5500 (you SHOULD change the springs), and SHOULD run the guideplates an longer pushrods.
I've sold hundreds of the 1.7s, 95% on stock cam/springs-- No problems due to stock springs on apps below 5500 rpm.
If you don't believe me, contact Crower directly-- the manufacturer, cam maker, spring maker.
Sam
www.socaldakota.com
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99 r/t
Dodge Dakota
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10/26/2003
09:54:03
| RE: Crower 1.7 and M1 on a 318
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Will the crower 1.7's help my quarter mile times any? thanks
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gen1dak
Dodge Dakota
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10/26/2003
10:08:18
| RE: Crower 1.7 and M1 on a 318
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I am not saying the stock springs cannot compress to .500 liftwithout coil bind. I am saying they will not live long.They most certainly ARE NOT "GOOD" to .500" lift. Can you wipe out a cam lobe with a roller rocker? Not as likely as with a flat tappet, but are you telling me it can't happen? That roller isn't a failsafe. It won't prevent cam damage. More likely, the lifter will compress, the pushrod will flex and punch through the rocker arm. No wait, there's a roller there too (if it's an aftermarket model). Hmmm, I guess nothing will happen and it's all my imagination. Keep in mind, just going to a 1.7 won't do this. I was speaking more in the general aspect of screwing up a valvetrain with too much cam (or excess ratio), not enough valvespring clearance, etc. It doesn't matter how many you've sold. Look, I'm not discouraging anyone from going to higher ratio rockers, the ones you sell or anyone else's. All I'm saying is do it right, get the better springs. (Keep in mind, I don't sell auto parts). Going to 1.7's on stock springs puts lift just over the max AS STATED BY MOPAR PERFORMANCE. Is Mopar saying this to get greater sales on HP springs? Maybe. Is Crower saying it's not a problem to get more sales on 1.7's? Maybe. Will most buyers get off without having a problem? Maybe. Good for them. And MAYBE I'll see ya on the side of the road.
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gen1dak
Dodge Dakota
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10/26/2003
12:14:10
| RE: Crower 1.7 and M1 on a 318
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I was looking back over your definition of "bind." Coil bind is the physical "binding" of the coils in a valve spring. This has nothing to do with rpms, per se. Bind occurs when there is insufficient room for the spring to compress under the lift generated by a cam lobe. If you have 1.64" install height. Subtract .060 for coil clearance. Subtract coil bind height (anywhere from 1.1-1.2"on average. This gives the max available room for cam lobe lift. (NOTE, I said cam lobe lift, not lift at the valve). If the lobe lift is greater than this number, you WILL break a rocker, collapse a lifter, and/or wipe out the cam lobe. Why do you think there are dished spring retainers that allow spring install heights of 1.8"? Why do you think valvespring seats are cut down? Coil bind IS NOT related to rpm. The cam lifts just as much at 1000 rpms as it does at 6000 rpms. Valve float IS rpm-related! Valve float occurs when the springs are unable to maintain control of the valves due to engine speeds exceeding spring design parameters. This is why heavier springs are needed to keep the valves under control at higher rpms. It's a little thing called inertia....and compressing springs beyond their limits, even if they don't bind, will cause early failure...and possibly a dropped valve. Better springs or a new piston, cylinder sleeve, and head repair. All this being said, adding the 1.7 rockers without springs, yeah, you'll get by, but it's thin when reliability is factored in. You know RTD, one would think you'd jump on board. Offer a 10% discount on a package that included springs. It's the difference between being good enough for a while and being better than new.
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graphiteRT
R/T
10/27/2003
22:07:55
| RE: Crower 1.7 and M1 on a 318
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OK, I'll start the trend. Looking for a set of Crower springs to replace the MP .600 lift springs I have now. Sammy, how about hooking a brutha up?
Broke one the other day(fortunately didn't drop a valve) and these are in no way abused. Just goes to show that no matter what you choose, there are other factors that can give you problems....aggressive cam profiles with steep ramp rates, just a freaky, bad spring, etc.
Sam, get me a price on a set and email it to me, would ya?
Thanks.
Bob
'01 Graphite CC R/T, MP headers, Magnaflow muffler into 'Cuda style exhaust, M1 2bbl, ported 2.02 R/T heads, custom grind cam, Crower SS rockers, Paxton Novi2000, Boyd's 20s w/Dunlop SP9000s, Featured in April '03 Sport Truck, Viper 4 wheel discs
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rtdkota
R/T
10/27/2003
23:19:22
| RE: Crower 1.7 and M1 on a 318
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Message:
Sorry, I put valve 'bind' when I should have put valve float.
The issues you stated about 'bind' really are an exaggeration for the general user, especially with a automatic and nothing more than a mopar PCM w/5200 rpm shift point.
Sure, I recommend people run a better spring, and I sell them... but for the general user, stock is fine-- they are more likely to have a cracked magnum stock head before they would ever break a mopar stock valve spring.
BOB-- I'll get some prices to you tomorrow-- we are just starting to clean up and get things going again here at the house-- we evacuated because of the fire-- moved a lot of stuff out-- but I stayed here with my dog and a garden hose...
fun fun-- but we were very lucky. I have some amazing video of the fire.
Sam
www.socaldakota.com
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jeffb
Dodge Dakota
JOIN HERE
10/28/2003
09:37:24
| RE: Crower 1.7 and M1 on a 318
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Message:
Thanks for all of the replys and information. Sam, really sorry about the fires and I hope all is well. When you get things going again, give me some info on your springs when you can. I would at least like to evaluate my choices of new RR and springs vs just RRs.
Thanks
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Wadak
Dodge Dakota
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11/22/2003
01:01:41
| RE: Crower 1.7 and M1 on a 318
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Sam since were on the subject of roller rockers. I was thinking about adding a set to a 92 5.2 4x4, it currently has about 95000 miles. Any thoughts?
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rtdkota
R/T
11/25/2003
02:50:06
| RE: Crower 1.7 and M1 on a 318
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Message:
With that many miles-- do valve springs too. The stockers are pretty weak, and adding additional lift on them would be a bummer if you had a spring go on ya (it happens, though rare).
I sell the springs, etc.. email me and I'll get ya a quote on the entire setup (modded and powder coated valve covers too if you want).
Sam
619-274-1292
www.socaldakota.com
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