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07:12:40 - 04/29/2024
V6 Dakotas
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gen1dak
Dodge Dakota
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10/29/2004
22:44:03
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 Subject: RE: Magnum heads on pre-mag block?
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On LA's you know where it is. This allows the valve to open into the exhaust crossover that LA heads have in their center sections. On the Magnums, the EGR is at the rear of the intake on the passenger side, behind the "beer barrel" intake section. The EGR Magnums have an EGR tube that brings exhaust from the passenger side exhaust manifold to the rear/passenger side of the intake. Thus, the location of the EGR valve on Magnums. Works the same way, just located elsewhere, and this is why the Magnum heads don't have, or need exhaust crossover passages like the LA's. Glad to help out.
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jagbor
Dodge Dakota
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11/01/2004
11:14:35
|  RE: Magnum heads on pre-mag block?
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Thanks gen1dak for the info-I called Mancini Racing and was advised that the P4452747 heads are on back order(date of delivery unknown) & cost $749 US each-by the time I get these to Canada I'm looking at ~$2500 or $83/1hp gain! I went to the local Dodge dealer & of course they have a catalogue with the P4452747 heads but don't have any in stock. It was suggested I take my truck to a high-perf machine shop in town and have my heads re-worked to accept .200" intake valves(I think this is what the guy said so that my heads would resemble the P4452747 heads?) & then "shaving off a couple thousand from the heads?" Are either of these options possible for my engine? What kind of costs are reasonable for this type of work? He also advised me to install a new camshaft. What do you think about these options gen1dak?
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vern
Dodge Dakota
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11/01/2004
18:24:57
| RE: Magnum heads on pre-mag block?
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jagbor-2.02 int valves are good for high rpm,s
but that will take away alot of bottom end torque,
i,d invest the money in opening up the valve pockets and a mild port job and have the heads milled .010-.015 thousands to up your compression
some and a good 3 angle valve job.
this will cost in the $350 range and net you 15-25hp
a cam $300 if its a roller,less if its a flat tappet[i don,t remember the yr of your truck]
if its 88 or newer it should have a roller cam
this could net you 10-15hp depending on cam,
just remember not to go bigger then the pcm can deal with,[ask sales person if you go this route]
by the way i,m not gen1dak
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gen1dak
Dodge Dakota
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11/02/2004
03:06:38
| RE: Magnum heads on pre-mag block?
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Yeah, the 2.02's will really help upper rpm breathing, but since it isn't a max-effort engine, I'd hang with 1.88 intake valves. Better low rpm torque, and still great flow up high. You can gain most of the benefits of the swirl-ported units on back-order by reworking your stockers. Not a clue on shop rates, but they should be able to quote a number, and it should be considerably less than new heads. Shaving the heads would shore up any lost torque from larger valves. Just don't go crazy there, or you'll wind up with a premium gas-only situation. Definitely want a cam like the one I already mentioned.
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jagbor
Dodge Dakota
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11/03/2004
15:24:11
| RE: Magnum heads on pre-mag block?
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Thanks gen1dak & vern for the info. I called a local auto machine shop & was advised that total cost of labour/shaving .010-.015" off the heads/"bull" work & porting + new set of valves + new 901 springs would cost $800 Canadian-is this reasonable?. This of course does not include removal of heads/cost for new camshaft or install of new camshaft. In addition, I was told that it is highly unlikely that any camshaft company would be able to re-grind my existing camshaft for use with the above re-worked heads because it is a cast steel core & cannot be "re-hard faced." What does this mean? Is it my understanding gen1dak that your advice was just to do away with my camshaft anyway and get a "254HR-12 grind camshaft & 901 springs" from Competition Cams?
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vern
Dodge Dakota
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11/03/2004
18:10:28
| RE: Magnum heads on pre-mag block?
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here where i live,in the northeastern states,
bowl work $100-150,shave heads $10-15 per cyl or $30-45 per head,so i,ll say $250us plus 40%=$350
canadian,that leaves $450 for valves,springs etc
when you say valves are you replacing the ext valves also? because if your going with 1.88 int
you need the 1.60 ext,because the ext needs to breathe as well.
hughesengines.com can reground your cam for $197us and springs are $76us,go to their site and check them out they may do the head work cheaper
they are nice to talk too.
good luck
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gen1dak
Dodge Dakota
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11/03/2004
19:50:18
| RE: Magnum heads on pre-mag block?
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Jagbor, you understood correctly on my statements for the cam. It'd run more than the Hughes regrind, but you would be starting with a new cam. I've had really good results with CC....not knockin' Hughes, you understand. It's just my prefs to go with CompCams.
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gen1dak
Dodge Dakota
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11/03/2004
19:57:50
| RE: Magnum heads on pre-mag block?
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On hard-facing....it's a treatment intended to make the friction surface more durable so it'll last. Basically, a poorer quality steel is used, then treated to make it harder. Typically, the hot setup for roller cams, for example, is to grind them from steel billet.
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jagbor
Dodge Dakota
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11/04/2004
11:15:28
| RE: Magnum heads on pre-mag block?
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Thanks Gen1Dak and Vern for the info-I will call a few other shops in my local area to get some estimates on the head work. I think if I had the heads re-worked in the US that by the time I shipped them there and paid to have them shippped back to me, it would be more expensive than just getting the work done in Canada. Is the internet address for compcams "compcams.com? as there are a number of companies called competition cams. Where are they located? Gen1dak.....if it is compcams.com, when I input the 254HR-12 to search for the camshaft you suggested, it does not show up in their on-line catalogue-is this a custom order? There is a company called ColtCams in Aldergrove, BC who advised me that a new camshaft for my truck would be $189 + my core-can you give me more specs other than 254HR-12 or if they are a reputable company, would they know what this means once I give them my engine size/truck year etc? You mentioned .480 duration/.480 lift-is this correct? What questions should I be asking of ColtCams regarding the camsahft they may be giving me?
Thanks again for the info-this forum is great for someone like myself who is new to daks & not so inclined mechanically. It's great to know that guys like yourselves are willing to share your knowledge.
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jagbor
Dodge Dakota
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11/04/2004
13:54:45
|  RE: Magnum heads on pre-mag block?
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Great news Gen1Dak & Vern-I just called another automotive machine shop in town and was advised that for all of the headwork/new valves(1.88" intake/1.60" exhaust)/new springs would be $575.
Price for a set of 901 springs is $80 Canadian & price for a both intake/exhaust valves is $130-are there different quality of springs/valves ie. stronger material or more for performance applications that I MUST ensure I get? This shop can also acquire a new camshaft for me & will be getting back to me with its cost based on the info you had provided me(254HR-12 grind/.480 duration and .480 lift).
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vern
Dodge Dakota
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11/04/2004
19:13:52
| RE: Magnum heads on pre-mag block?
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thats a good price for the valves and work,
the springs are usally rated for lift,that is so the springs don,t bind on max. lift of the cam,
be careful on the cam duration,the higher the dur.the higher up your power band will be,
ask who ever you are going to buy the cam from what the power band is.
they will ask you questions like,weight of truck,if your racing or street,rear gear ratio,towing,tire size,auto or std,4bbl or fuel injected etc
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gen1dak
Dodge Dakota
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11/04/2004
21:42:56
| RE: Magnum heads on pre-mag block?
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It is vital to use the proper springs. I have seen first-hand how shimmed valvesprings have failed under the increased load of a higher lift cam. A dropped valve can do some expensive damage. When a spring fails, it can lead to a dropped valve, and an engine at speed doesn't take long to beat the Hell out of itself with that valve. Use the suggested springs. It's cheap insurance, and will maintain maximum performance results from the cam by properly controlling the valvetrain. The 254HR-12 yields .450 intake/exhaust when used with your 1.5:1 rockers. It becomes .480 with 1.6:1 rockers. So, .450 lift, gross duration is 254 intake/262 exhaust (stock is only 240 degrees), duration @ .050 is 199 intake/206 exhaust (stock is just damned pathetic). Lobe separation angle is 112 degrees. (Note that lobe separation and installed lobe centerline are not the same thing). The lobe separation angle is important for computer-controlled fuel injected application. The higher separation angles reduce valve overlap, which smoothes the idle, and generates higher vacuum signals. Keeps the MAP sensor happy. This would be a custom grind cam since, as far as I know they don't stock the V6, just the V8 version. Certainly this is not the only possible cam spec that could be used, but for an essentially stock, non-PCM-modded unit, it'll act the same around town, but will make much better power as the revs rise, but maintains the same operating rpm range as your stocker cam. And it'll work with all your stock electronics. It is compcams.com
If you call them (1-800-999-0853) and tell them the cam grind, they will know what you mean, and if you talk it over, they may offer a variation on this theme that'll work even better. They're constantly improving things. I've had great results in the past, and have a new custom CC grind in my 360 Magnum (Can you say neckbrace?) You will not be disappointed, and they will work with you to get the right setup. Again, the 254 isn't a killer HP cam. You can only do so much within the stock parameters of the electronics. Still, it's quite an improvement. As for ColtCams. Ask the same questions I listed in the cam specs. Gross lift, gross duration, duration "at fifty" which is the .050" reference (and is considered a much closer quote for the net duration of the cam), and ask about lobe separation. You might squeak by with 110, but 112-114 degree separation angles are better for your application.
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jagbor
Dodge Dakota
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11/06/2004
21:01:53
| RE: Magnum heads on pre-mag block?
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Thanks gen1dak & Vern-I tried to call comp.cams but I am unable to use thier toll-free line(may be it's just from work that I can't use it)-I sent them an e-mail so am waiting for a response. Anyways.......re the camshaft-I've read that the type of camshaft I use should match the rpm's that my truck generally runs at. Is this correct? When I towed the 13 foot Trillium tailer this fall, my rpm's "with OD off" was around 2400 at say 55mph(90 kms/hr). When I explained this to the guy at ColtCams, he suggested that the 254HR-12 grind would likely not show its true performance until above 3000rpm's & since I advised him that I rarely have my truck revving that high, he suggested getting one that would improve low end torque. The specs he gave me were:
175 degrees @ .050 intake
200 degrees @ .050 exhaust
.460 lift
111 lobe separation
cost: $175 Cdn + my old camshaft
Please understand...I am not questioning your expertise/knowledge gen1dak or Vern but does this guy know what he's talking about? As you can tell, I am new to all of this & just want to make sure I get the most bang for my buck since I only want to do this process once!
Thanks again for the time you to take to answer.
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gen1dak
Dodge Dakota
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11/07/2004
00:18:02
| RE: Magnum heads on pre-mag block?
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The 111 degree separation will tend to lower the torque peak rpm, and the cam will have a slightly narrower power band, which isn't a big deal in a stock-style cam. It has good lift, but that intake duration SUCKS! This may help maintain good low rpm vacuum to help cover the 111 degree lobe sep, and thus keep the computer happy, but it's not the way I would go. Your intake valve will open further, and that improves flow, but with a net duration basically stock, it won't be open for long. Basically, your improvements will occur from a little better intake flow, relative to an improved (over stock) exhaust flow. The better the flow balance between intake and exhaust, the better your power will be (which is all relative to overall cam specs). CC takes the same basic approach by hanging the exhaust open longer than the intake, but they also increase the intake duration to allow for better cylinder filling. Remember, you're gonna be living with this cam for a long time. I'm not saying Colt's cam won't improve power, but you already know my vote on the matter. Oh, if you're wondering about qualifications. CompCams grinds cams for all sorts of championship race teams in NASCAR, NHRA, etc, so I'd say they know a little bit about cams.
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vern
Dodge Dakota
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11/07/2004
08:45:51
| RE: Magnum heads on pre-mag block?
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i agree with gen1dak that cam does,nt sound like much.
but we don,t know alot about that cam,like how fast the ramps are,this has to do with how fast or slow the valves open and close,theres alot to making the cam so i won,t go into it now but i,ll give you some cam #s to compare it with.
these two cams are rollers from hughes engines
just because it was the easiest to get quick,so here goes.
her9204al-v6 1.5 rocker ratio
int. .451,exh.479
dur. 192, 204@50%
lobe separation 114
power band=idle-4600 rpm
strong bottom end torque
her0814al-v6 1.5 rocker ratio
int. .480,exh.489
dur. 208, 214@50%
lobe separation 114
power band=idle-5500
good bottom end and mid range
hope this helps for comparing
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gen1dak
Dodge Dakota
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11/07/2004
21:10:54
| RE: Magnum heads on pre-mag block?
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Yeah. That her9204 looks like a good choice for an essentially stock setup that would still do well in emissions. It would be a strong second choice in my book. Basically, if they could get it out quickly and especially if the price was right, I'd probably go with it.
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jagbor
Dodge Dakota
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11/08/2004
13:14:04
| RE: Magnum heads on pre-mag block?
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Thanks again gen1dak & Vern but now I am getting really confused. Verns examples of 2 camshafts & their specs that I may want to use talk about "power band idle rpm of 4600/5500" respectively-what is this? what does it mean? these are both rpm levels that I NEVER get my truck to reach so I'm not quite understanding how a camshaft with either of these 2 specs is going to help me tow my 1500 lb trailer-please explain. I wasn't able to contact CompCams yet but will do so during this week and get back to you with thier recommendation(s).
Thanks again and have a great day!
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jagbor
Dodge Dakota
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11/08/2004
15:13:57
|  RE: Magnum heads on pre-mag block?
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Gen1dak & Vern-I managed to call Compcams today but unbfortunately they advised me that they cannot help me. I spoke to Jeff who said they do not have a "core" camshaft for my 90 3.9L. When I gave him the specs from the HR254-12 grind, he advised "this is a camshaft for a V8 magnum" & then advised again that he is unable to help me-this is rather DISAPPOINTING or am I just not giving him the correct info? Jeff also said that they do not have a welder to "add material onto my existing camshaft" so that they could then custom grind it for me-he recommended I contact webcamshaftsinc.com in California for this-ever heard of these guys? What's their reputation? or should I just be trying to contact Hughesengines? He also advised that it would not be a problem to "weld/add material" to my camshaft despite it being cast(vs. billet) & then have it custom ground-as I go along, this seems to be getting more and more expensive. Anyways....your suggestions/input would be greatly appreciated.
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gen1dak
Dodge Dakota
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11/08/2004
17:36:33
| RE: Magnum heads on pre-mag block?
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The power band rating refers to the rpm range that the cam makes best power. Pretty much any mod to a cam to increase power, even for low rpm torque, will likely increase upper rpm power and range, even if minimally. Also, if you ever have a decent onramp, pulling a trailer, you'll appreciate having more midrange and upper rpm power to get up to speed. The rpm range just means best power within that range. That's not to say it won't pull further, but means power will level, then fall off above that rpm range. The CC deal is a bit perplexing. Sounds like they have a moron taking tech calls. Anyway, CC does make custom cams, but at this point I'd go with the Hughes unit. If CC is gonna make that sort of customer service error, they shouldn't be rewarded with further effort. Don't fool with an old cam re-weld. Call Hughes and see what they can tell ya.
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vern
Dodge Dakota
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11/08/2004
18:57:07
| RE: Magnum heads on pre-mag block?
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jagbor i agree with gen1dak explanation on the power band and the guy at Comp Cam that the grinds i give you are v8 specs also,because like gen1dak said earlier these are v8s,5.2,318s with two cyl removed.
so most every thing you can do to a 5.2 for performance[power,torque]you can do to the 3.9s,
hughes engines found that theres a market for 3.9 parts and if they get enough people interested in performance parts they,re going to do more v6 build ups,GIVE THEM A CALL the most they can say CAN,T HELP YOU
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