84Z28406

Well, because my POS truck decided to eat all my parts money for the year, I won't be new heads for my 350 and as such won't be getting the cam I had planned on. All the same I'd like more cam than stock. It'll have headers and an Edelbrock Performer RPM intake. Manual transmission. I'm not sure which heads it has because I haven't taken the valve covers off but it's safe to assume they're smog junk heads. That being said, which would better suit the combo. http://www.jegs.com/i/Comp-Cams/249/CL12-242-2/10002/-1 or http://www.jegs.com/i/Comp-Cams/249/CL12-238-2/10002/-1 or http://www.jegs.com/i/Comp-Cams/249/CL12-234-2/10002/-1 .

tony_cogliandro

iTrader: (3)

i like the zz4 with .474 and .510 in the exhaust and you can get one for under 100.00. just look around. but it is a roller cam but so are the ones you posted. dont know what type of tapits you already have but if its after 87 they might already be roller and you can use them with the new cam, or you can use the flat tappet.
dont know what heads you are thinking of but you will need new ss valves, steel rockers, full roller; you should port and polish the heads and match them to the intake, and figure to spend 500.00 on what you will need to put on the heads after you get them.

tony_cogliandro

iTrader: (3)

i like the zz4 with .474 and .510 in the exhaust and you can get one for under 100.00. just look around. but it is a roller cam but so are the ones you posted. dont know what type of tapits you already have but if its after 87 they might already be roller and you can use them with the new cam, or you can use the flat tappet.
dont know what heads you are thinking of but you will need new ss valves, steel rockers, full roller; you should port and polish the heads and match them to the intake, and figure to spend 500.00 on what you will need to put on the heads after you get them.

84Z28406

The block is pre-86 so it has flat tappets, like the cams I linked. I'm also concerned about max lift because I've heard that .480" is max on stock heads and I'm not invest any money into these heads since they'll be trash next year anyways. Except for perhaps springs, they'd have to be upgraded.

Atilla the Fun

with smog heads, assuming 1.94/1.50" valves, the exhaust ports are too weak for a cam only having 6 degrees more exhaust duration at .050", and you're probably down around 8.2:1 compression. And having a T5/3.23:1 combo, I suggest you start with either COMP's DualEnergy255, or COMP's PureEnergy. If you don't mind not using fifth gear, you might step up to the DualEnergy265.

84Z28406

I'll look into the cams you suggested, but why would the DualEnergy 265 be a problem for fifth gear?

tony_cogliandro

iTrader: (3)

you are right. had my head hidden from the sun - was thinking roller and reading hydro - sorry.

Firechicken355

Take it from a man of experience, DO NOT install a flat tappet cam unless you are going to run special oil or 100% synthetic oil. Our good friends at the EPA made the oil companies reduce the anti wear additives by 50% starting with SM rated oils. The stiffer valve springs used with performance cams needed the additional additives. I am running a Comp Cams XE268 cam kit and use diesel oil and an additive to keep it alive. A roller cam works just fine with with the new oil, but the old school flat tappets will grind themselves away unless you watch what oil you use. Yes the rollers are more expensive , but you will kiss yourself later if you save up your money and put a cam in you don't have to worry about.

84Z28406

Fair enough, I figured that was about what happened.

Thanks for the advice. I've read about the new ZDDP deficient oils and the need for additive. Rollers would be nice, but thats not in the budget for this year. This year is a hydro cam and parts I've already got on hand. Not much, but all I've got this year. She's been sitting for too long to put it off any longer. $575 canadian is a bit steep for retrofit lifters when I can put that elsewhere for the moment.

Atilla the Fun

You'll have to get both the carburetor and distributor just perfect to run the 265 in fifth, and even then, no slower than about 45 mph. That 265 is truly great from 1500 rpm up, but has a noticeable idle, and that means less torque than a stock cam, up to about 1500 rpm. It'll pull first gear just fine right at idle, but with each upshift, you increase the load on the engine. Ever heard of "trailer-hitching" ? Or "surging"? There's good reason why Crane used to specify cruising rpm for each cam. Your 0.625:1 fifth drops your cruising rpm a couple hundred rpm below most other 5-speeds, which typically have a fifth gear of 0.68:1-0.85:1, and that's a good way to experience surging. You should be running a 3.73:1 anyway, but that's not what this thread is for.

84Z28406

Ok, the surging you describe I'm familiar with, my friends LT1 does that when the engine spins too low. You're probably right that that it'll do that. Most of my highway cruising is done at 65 mph or higher though, but even if I can't use fifth for cruising, I'm too concerned. Where did you get 0.625:1 as my fifth gear ratio though? I had always thought it was 0.73:1. I also agree with your suggestion to get 3.73s, my 3.23s have to go.

Atilla the Fun

When GM started installing the T5s in our third gens late in the 1982 calendar year, all the V8 T5s did have the 0.725:1 fifth, but sometime thereafter, I'm not sure exactly when, all the LG4 then LO3 cars got the 0.625:1 fifth, and only the TPI 305s continued to use the 0.725:1 fifth. The easiest way to tell is to calculate your cruising rpm both ways, and see which result matches what your tach is showing. With 215/65R15 tires, the .625 gives 1700 rpm at 65 mph, while the .725 gives nearly 2000 rpm.

84Z28406

Ah, I wasn't aware of that, good to know. All the same, I do have the 0.73:1 fifth gear. I've done the math in the past and come up with around 2000 rpm. What are your thoughts on the DualEnergy 275? Too much for the combo?

Atilla the Fun

I've experienced the DE265 in a combo very much like yours, and I know his car was .625 and we spent weeks on his dizzy and carb, that's how I know it wouldn't pull 5th below 1200 rpm. I've driven the DE275 in slightly wilder combos than yours, and it's not that big a cam, but it'll feel more like an on/off switch than a DE265. Without great tuning, you'll be able to tell when the cam starts to come into it's best rpm band. With automatics, the converter tends to mask the feel somewhat. These DE cams are '80s tech, but I'm using them because the ramps on the intake lobes are less intense, and seem to resist going flat, better than the much newer XE lobes. I'm guessing that you can't afford to spend the extra $110 for nitriding,it's pretty new, but it seems to make a non-roller about foolproof. I've seen 6 installed so far this summer, and so far none of them has developed a bad lobe.

ap72

go wit the E1785 cam kit from elgin, cam and lifters is a hair under $100 and it will give you an awesome sound and great midrange (what you need on the street).

http://competitionproducts.com/prodi...number=E1785PM

There's a link to buy it, their tech help and prices are both really good there. Run it on "z28" type springs (about $40 a set for those).

If you're really worried about low RPM surging then the E1065PM would be a better match, you will still have a little better idle sound but the power curve will flatten out this cam can also be ran with cheapo Z28 springs.

84Z28406

Yeah, I'm not going to bother with nitriding on this cam. I will when I get my XE cam next year. As for an on off switch, shouldn't be too much different from my new canyon, those 4 cylinder engines are worthless under 4k.

Atilla the Fun

Forget that Elgin, it's single pattern, has more overlap than a DE275, yet would run out of breath about where a DE265 will.

ap72

The single pattern and the increased overlap was the point of recomending that cam. a LOT less of a split is needed than most people think and in many cases (like this one) no i/e split is really needed at all- a narrower LSA just means you'll have increased midrange. at the cost of a little top end.

That cam is designed to make the most of a mostly stock situation, low compression, stoch heads, and a intake/headers swap. Your peak hp will be down compared to a split pattern cam with a slightly wider LSA, BUT your et will be lower and your tires will wear out faster with the one I suggested. Stock heads need a narrowed LSA to perform well (track guys run with 95-105 LSA's all of the time on stock heads). You will not read about this in any car magazines because it does lower your peak hp and peak numbers sell magazines to uneduacted masses, HOWEVER if you want to perform well especailly in a undergeared Camaro on the street You'll need a single pattern on a narrow LSA.

BTW bad heads, open exahust, long stroke, and small bore all are things that point to a narrow LSA, a 110 LSA would be more appropraite on a sbc 348 with a set of AFR 235's that was bracket racing.

84Z28406

I guess I'll step back from the brink and use the DE 265. I suppose a little streetability never hurt anybody. I've got next summer for something you can't drive in a parking lot.

84Z28406

So the bigger cam is $45 cheaper, so I guess to hell with low end. These are the recommended springs. http://www.summitracing.com/parts/CCA-981-16/ Will I be able to use stock locks and retainers with these springs?

ap72

you can probably get bywith stock retainers, I'd get new locks for the $5 that they cost- its cheap insurance. YOu're also going to need to check your retainer to seal clearance. This cam will be okay in your application but you could do a little better- an Isky Mega264 is more cam than I previosly recomended and it costs more than a cheap Elgin cam, BUT it is also a VERY good street cam, a lot of people run it with Vortec 350's and make killer midrange, it coud still prove healthy in your combo. If you insist on going with the DE275 atleast swap in a thinner head gasket to improve your compression/quench, it'll take an hour longer than a plain cam swap, Mr. Gasket makes .020" gaskets that are relatively cheap and hold up well. A little bowl work in your heads would help too, but I think you're trying to avoid getting too far involved.

84Z28406

It was my understanding that most engines cam from the factory with steel shim type head gaskets that were thinner than .020". Am I mistaken?

ap72

yes you are mistaken.

84Z28406

Very well, my bad.

ap72

Its cool, everyone has to learn these things sometime- we're not born knowing it all.