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07:10:42 - 04/24/2024
V8 Dakotas
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Zac
Dodge Dakota
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2/28/2005
13:47:46
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 Subject: RE: pre mag mods
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could i use thinner head gaskets to increase compression slightly? or would the intake manifold not match up properly?what is the highest compression ratio i could have with 87 octane gas?
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gen1dak
Dodge Dakota
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2/28/2005
16:05:03
| RE: pre mag mods
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Yeah, it'd work, but consider these tidbits: Back in my Charger days, I didn't know about having to mill the intake. I had the heads milled about .020. Everything still bolted up and it ran fine, BUT, I wound up having to back off the timing a bit. Now, maybe with the better breathing, my carb was a bit lean, and could've benefitted from a re-jet, bit not having any clue at the time, I had to back it off to avoid detonation. It wasn't so lean that I had excessive engine heat, and never burned a valve, so it's couldn't have been all that lean. So, I gave up a little bottom-end because I didn't know better, and thought I had to have every last bit of compression ratio I could get....even though I was running 92 octane gas. A lower CR engine running full ignition advance will always run better than the same engine with higher CR and less ignition advance, all else being equal. My Shelby's original 318 CR was the same as yours, and, with a slight tweak in the computer for ignition timing, required a minimum 91 octane. Also, since any street cam you add will generate more cylinder pressure (in effect, increasing your effective CR) this must be considered too. So, with your stock ignition curve, you can now run on 87 octane, right? Dropping CR with the 360 heads, then increasing cylinder filling, and pressure with a better cam will increase effective CR, so your net CR may change very little, maybe even be a bit higher than stock, depends on the cam and breathing ability. So, son't sweat the CR. I'd keep the static CR somewhere around 8.5:1, give or take, for 87 octane. The head swap will put you around 8.25-8.5:1. Using 1/2 thickness gaskets will put you at a disadvantage in longevity. They're more likely to blow out as mileage increases, quicker to start leaking. This is ideally more a quick fix. It works fine, but, again, potential longevity is decreased if you plan on really running this thing. Use the standard thickness, and relax about the last few tenths of a point. It's a lot worse having to live with a finicky, high-octane machine, than one that's happy on 87. I did the same with the 360 Magnum now in my Shelby. I am quite happy with the stock 8.9:1CR. Hotter cam, yes, but thanks to the added quench area in the heads, it has a bit more detonation resistance, and I'm sure 87 octane will still work fine. I could snake out a few more horses and run it on premium, but it's just not worth it to me.
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Zac
Dodge Dakota
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2/28/2005
22:40:09
| RE: pre mag mods
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thanks again. I was thinking the same way as you said you did. your help, gen1dak and that of Mike S. has really given me the confidence to take on a project of this size. This will be my first in a long list of mods for my truck. Being as i am only 17 I was kinda nervous about tearing my truck apart based on someone's word. But you two have have convinced me with the facts and personal experience. You have answered all of the questions i had but I have thought of a couple more. what is your projected HP and TQ gains from a setup of this kind? just a ballpark figure. for the exhaust what if i cant find 92-93 manifolds would it be better to use later magnum manifolds or save my money for headers? full length or shorty?
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gen1dak
Dodge Dakota
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3/01/2005
21:15:26
| RE: pre mag mods
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Ahhh, 17. I remember 17. Don't sweat it Zac, you can do it. I was 17 in my Charger days, and I didn't have the net to fall back on. Made a lot of lucky guesses, but that car was wicked! Anyway, let's compare the 318 Magnum to your goal. The 1994 model was rate at 230hp/300lbs torque. Now, adding better breathing to your engine is just like the 318 Magnum, in the sense that it has, aside from minor valve size differences, 360 Magnum heads and intake. The 318 Magnum has a short duration cam with .432 lift.
You're looking at a short duration cam with more lift, meaning computer-friendly, but more HP. Toss in at least a Magnum-style exhaust, and you're gonna edge it out. Now, these are net power figures, not gross, at the crank numbers...just for perspective. Suffice it to say, 300hp at the crank off the top of my head. Subtract 20% for an automatic, 15% for a stick, and you get the net figures. The Mopar 360 crate engine, with a nothing cam is rated at 300hp at the crank, which explains their 240-250hp net figures.
On the exhaust, it's all in what you're able to afford. Good full length headers with epoxy coating will run over $300 bucks. Even the '93 and up stockers flow well, and trade a bit of hp for a tad more low rpm power, they'll never rust out, they will keep underhood temps low, all the usual benefits, especially in that they're a lot cheaper. For max power, headers are the way to go, however. I gotta ask though, why not just carb that sucker? I mean, keeping the overall TBI package is cool. Nothing wrong with that. But it begs the question, Why not 360 heads, a Performer RPN air gap intake, 800cfm carb, and an even better cam like the CompCams Xtreme Energy 268, or something along those lines?
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Tom Byrne
Dodge Dakota
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3/01/2005
21:40:33
| RE: pre mag mods
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Some great tips here. I am going to work on my Shelby Dak's engine this year. It was painted last year and has the correct graphics. The transmission was done in 2003 (2200 stall) and has less than 1000 miles on it. I want to keep the TBI as I want the truck to "look" as original as possible. Is there a way to adapt the 318/360 TBI to a 4bbl manifold? Are there any advantages? I already have true 2 inch duals and twin cats. Hooker does make a header for 318-LA Daks. The are available at Summit for $359.95. Part #HOK-5803HKR
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Zac
Dodge Dakota
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3/02/2005
01:16:58
| RE: pre mag mods
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I dont know I guess i just thought that I would get better gas mileage with the TBI. I may consider switching to carb later but I think I will try this first. Could you give me the exact part numbers for the 264HR-12 cam and those valve springs so I order the right thing. I am going to start collecting parts soon hopefully. I am going to install it all at once so i I have as little down time as possible. This is my daily driver and my first truck.Once I get out of school and am making more money this swap shouldnt be too hard too pull off.I am only working part-time at a bodyshop right now but I will be fulltime in July. Is there any distict way to tell a 360 from a 318. just so I dont get the wrong stuff. Will my tranny( A500 i think) stand up to that power? what about my rearend? I was wanting to regear to a 3.92 and get a posi anyway so it wouldn't be too bad. What would be good upgrades? I was on the Phoenix transmission site and they have a Street/Strip tranny with a stall up to 2800 RPM for $1500. would that be a good replacement?
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Mike S.
Dodge Dakota
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3/02/2005
06:00:18
| RE: pre mag mods
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The Phoenix trans is pretty good for the price. I bought one about 4 years ago and it lasted till I started using nitrous. I'm still using the A500 but I had it built at Bilbrey racing in Louisville KY. The A500 is basically the same as a old 904 with overdrive. It can be built too handle around 550hp but that's it(per my trans builder). As far as your rearend, Randy's ring & pinion has great prices for a gear set and sure-grip diff.
Mike S.
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Zac
Dodge Dakota
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3/02/2005
19:51:31
| RE: pre mag mods
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could one of you give me the rundown on the cam install. anything I should look out for? Will I need new bearings? how hard is it to intall those? my engine has 204000 km on it.
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gen1dak
Dodge Dakota
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3/02/2005
21:26:26
| RE: pre mag mods
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Cam bearings...just say yes.
Like Mike said about the A500, just keep the stall down more like 2200 rpm.
Also, again, Randy's is a good place for rears. Your 8 1/4 will be fine with a freshen-up job and the limited-slip/posi style upgrade.
One thing you need to get is "Small Block 'A' Engines". Manciniracing.com has it for $10 (plus shipping). It has quite a bit of useful info on these engines, discusses engine blueprinting, assembly, etc. Nothing like being able to lay your hands on the info.
http://store.yahoo.com/chucker54/mopper.html
The most definitive way to determine what an engine is, is by the casting number on the right side of the block. There will be a sever digit number, a dash, a three digit number indicating the engine displacement, followed by another dash and a single digit. Looking at the heads, if you can see the intake and/or exhaust ports, the 360 ports will be bigger than the 318. This is especially obvious on the intake side. The ports are a bit wider, and a good bit taller. Flip the heads over, and the 318 valves are tiny, while the 360 valves take up most of the area in the head.
When disassembling the engine, note the placement of the retainer plates on the lifters. You'll want to remember how they are placed. Order isn't an issue, just the way they lay in relation to the block and lifters. If you go back with a roller cam, it will not require the traditional cam break-in, but it's a good idea to run the engine 20 minutes to "heat treat" the new valve springs, then shut it off, let it cool. This will greatly improve spring life and longevity.
The cam part number for the 264HR-12 is 20-624-9
The springs are 901-16. You should get some stronger pushrods. You can get them, even at the local parts place for a couple bucks each. The CompCams versions are #7937-16. The steel retainers are # 747-16, the locks are 626-16. Mancini Racing also has good prices on performance locks and retainers from Mopar, etc. Remember to get the A-engine parts, not the Magnum.
On the cam install, it's pretty easy, but if nothing else, get that book. It goes into detail on things.
This book http://www.amazon.com/exec/obidos/tg/detail/-/0895861283/qid=1109816018/sr=1-2/ref=sr_1_2/103-6647778-6796640?v=glance&s=books
covers, in detail, the teardown and re-assembly, with all the torque figures, etc. Very helpful. $13, and it'll point you in the right direction on what replacement parts to buy, and what can be re-used. Both are extremely useful, and should be your first investments.
Tom, there's no adapter plate for the offset TBI bolt pattern, but Summit does sell a generic adapter plate that can be "worked", and should make it do-able. Kinda drill-it-yourself. Advantages? Yeah, especially when comparing the 4V to a 318. If you have a 318 with a 360 intake, there's much less improvement, but new aluminum designs are still better than what is basically a 38 year old design.
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Zac
Dodge Dakota
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3/02/2005
22:44:44
| RE: pre mag mods
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just to make sure if I get the 360 PCM that would be the computer mods that they say that cam will need right?
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gen1dak
Dodge Dakota
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3/02/2005
23:32:07
| RE: pre mag mods
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Right, as well as the matching 360 TBI.
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Zac
Dodge Dakota
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3/03/2005
00:03:13
| RE: pre mag mods
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I was reading on the comp cams website and it said that if I didnt want to void the warranty I would have to use new comp cams lifters but i couldnt find any on their site? do i really need new lifters or could I just pull them off a low mileage donor and be done with it? also is it very difficult to install the cam and bearings? it is the one thing in the whole project that I am kinda nervous about? the rest im pretty sure i could handle but the cam is making me nervous
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gen1dak
Dodge Dakota
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3/03/2005
13:10:31
| RE: pre mag mods
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Generally, the new lifters deal is aimed at flat-tappet cams, not rollers. That's where the cam break-in is so critical. On initial startup, a flat tappet cam and lifter will "trade" metal as they are broken in. It's vital to do that correctly, so, as you can imagine, using a new cam, with mileage-hardened and worn used lifters can wipe out a new cam. Since roller cams do not do this, it's not an issue. Just make sure the rollers are in good working order, because, while they don't wear out from friction with the cam lobes, they will eventually fatigue and fail internally, or at the roller pinion. Overall, they do appear to have a very long service life in normal driving situations. It's always good to have fresh lifters, or at least some low mileage units. Those roller lifters cost quite a bit more than the flats, but if you had to get new ones, I'd head to Mancini Racing or Summit.
Installing a cam is very straightforward. Five bolts hold it in! You pull the first bolt, off comes the timing gear. Then there's the thrust plate, held in place by 4 bolts. Pull those, tap the plate loose, and the cam is free. Now, go to the rear of the engine, where the distributor sits. There's a gear there that's driven by the cam. This is the oil pump drive gear. If you're gonna have the engine on a stand, and plan on flipping it over, you need to go ahead and remove the gear so it won't fall out later and suffer damage. Otherwise, you can leave it in. Just lift and allow to spin as it rises, it pops right out. Be gingerly, no brute force here. That just breaks things. Anyway, next, put a bolt in the end of the cam (the single one you pulled first is fine). Screw it in 3-4 turns. Now you have a handle. Spin the cam to raise the liftes in their bores (you should already have the heads off, or at least the rocker arms to relieve all spring pressure, thus allowing the lifters to exert no pressure on the cam). So, the lifters are floating freely in their bores, and you may now, very slowly, begine sliding the cam out. The cam will immediately drop once it's moved an inch, so be ready. Have a free hand on the rear of the cam so it doesn't drop and damage the cam bearings. Slowly guide the cam out. DON'T FORCE ANYTHING! Each time the cam journals meet the next bearing, it needs to be straight as it meets, and it'll just slide right on through. Might need a little spin to ease it along. Don't be afraid to sprinkle a little oil on the journals to help ease things. Remember, the cam has no support when not in the bearings, and is heavier than you'd expect, so go slowly, and don't let go. Repeat the process till the cam is out.
Cam bearings. Actually, the cam bearings suffer little wear, even in higher mileage situations. Go into this expecting to replace them though. If not required, it's an unexpected bonus. A lot of times, something has managed to get onto a bearing surface and scratch it somehow. This begins the real wear, and it must be replaced. Get one of those little telescopic mirrors and inspect the bearings. See any little dings or scratches? Any signs of wear? If not, you can leave them alone. Did that on my first engine (117,000 miles when it was rebuilt and suped up), never had a problem. If you decide to replace them, bite the bullet. Take the block to a machine shop, have it hot-tanked, and have them put new bearings in. There are some special tools needed to do this. Not that there aren't fellows out there who do it in their back yards, but unless you're sure on this, you'll wind up fragging a new cam just a few miles down the road. Those bearings are pressed into place, and have to be lined up with the oil holes as well. Despite the forces involved, it's a rather delicate procedure.
Re-installing the cam is simply a reversal of removing it. Liberally oil the bearings and journals, take your time, and be gentle.
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Zac
Dodge Dakota
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3/03/2005
13:49:04
| RE: pre mag mods
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sorry to keep hounding on you about this but, are you sure that cam will work with my engine with the 360 upgrades. I just dont want to buy something for nothing. thanks
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Mike S.
Dodge Dakota
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3/03/2005
19:16:05
| RE: pre mag mods
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That cam should work fine. I ran a larger cam than that in my motor when it was similar too what your building. Good luck
Mike S.
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Zac
Dodge Dakota
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3/03/2005
21:06:38
| RE: pre mag mods
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Thank you for that. I just wanted to be sure. I am going to go the the local wreckers in the next little while and see if they have a good donor. what would be a decent price on the parts?
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gen1dak
Dodge Dakota
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3/03/2005
21:57:44
| RE: pre mag mods
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At my local "U-pull-it" an entire engine can be had for $150, and that's with a 30-day warranty. Naturally, buying it a part at a time would run about twice that, but that's the only reference I can offer there.
On the cam, here's another vote of confidence. It'll work. I have a write-up on a Shelby build-up from the early 90's. They did the 360 stuff, then started out using the original 340 Magnum cam from the late 60's-early 70's. It has a bit more duration, and slightly less lift than the CC cam we've talked about. They then played around with other things, but it worked fine. Suffice it to say wheelspin became an issue which mandated wider wheels and rubber. Just remember, the 360 stuff is able to feed an engine 42 cubes larger, so opening up a 318 with performance parts is no problem with the 360 mods.
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Zac
Dodge Dakota
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3/04/2005
00:00:14
| RE: pre mag mods
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right on. Maybe i could get the entire engine, take what i need and part out the rest. Thank you for your patience in answering all of my questions, you have been very helpful. When I started this post i had a small idea of the basic mods i wanted to do but you have built up my knowledge and my desire to make my so called "small" 318 into a more of a powerful engine. I was just wondering about my pushrods. The stockers arent strong enough or is it just extra insurance? also what is the length of the stock ones?
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Zac
Dodge Dakota
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3/04/2005
00:21:13
| RE: pre mag mods
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I just found a complete axle from a 92 dakota LSD w 3.91 gears that I am gonna get. The guy only wants 300 for entire thing. that is gonna help solve the traction part of my setup once it is done.
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Zac
Dodge Dakota
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3/04/2005
00:25:39
| RE: pre mag mods
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one question I forgot to ask is how can I correct my speedometer after i do the gear change?
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