CRN-104211 in summit

The cam says that it will not mess up the computer and the car will run fine. I highly doubt that right?

Is this any better than your LT1 cam? Thanks guys.

 

Your intuition is correct. A full exhaust on these cars warrents chip work. Any cam swap will require chip work. That is unless you want your car to be a slow gas guzzling, sputtering, surging undrivable mess.

 

I realize this is like, blasphemy, but I actually disagree with you for once, shifty.

well, somewhat.

the difference between the stock cam and that cam is almost marginal, the tpi 5-speeds came with a wilder cam then that.

I'd be willing to bet you could get away with putting it in your car without chip tuning, I'd be willing to bet it'd run <i>relatively</i> well too.(minimal spitting and sputtering, if you will.)

BUT, it'd never run at it's optimium, and it would be a gas guzzler.

basically what I'm saying is that they weren't false advertising, but a tuned engine with that cam would be far superior.

any of the lt1 cams are far better, but you couldn't get away with an lt1 cam without tuning, I don't think.

I wouldn't waste my time with that cam though, I'd swallow my pride, empty my wallet, and just spring for the lt1 cam/ valve springs/timing chain/various seals/gaskets/tuning equipment, and get to reading the prom tuning boards, it seems to be 90% of where all the cheap power comes from in the 305's.

it also seems to be the cheapest/quickest way to pull 200hp out of these things.

just my opinion though, and unfortunately it's all based off of reading and other peoples experiences, I still haven't done any of this meself.

 

I can attest to an '87 Peanut engine with the LT1 Cam putting down 180HP with a curve that was more like a small rolling hill... than a curve.

BROAD, and the engine sounded like a windup toy on that wide LSA. Something like 117º

I ran a COMP XE 262 on a 114ºLSA with 416 heads and a 350 and ran on the factory 5.7L prom for a while with 24lb injectors.

Yeah it ran rich, but there wasn't any spit/sputter. It ran fine. Went 14 flat in the quarter too. Which was pretty good considering what the plugs looked like afterwards.

That's before I started to tune.

Unfortunatly I didn't get to run the tuned version at the track because one of the rockerarm studs broke off and I got my Pro's/HSR at that point.





Those are my experiances. To answer the question, the ECM wont have much hitch with that cam. It even advertises the proper TPI power range, which is quite the tame cam.

 

This cam WILL throw off the ECM into a spitting, surging, gas hog of a mess. A stock LT1 cam in a 305 will do the same thing. You MIGHT get away with a stock Vortec truck cam with the stock tune. In a 350 the vortec cam will run just about perfect and the LT1 can work with a little fuel pressure rework and about 4* of timing advance.

Twilight, they are not talking about putting this cam in a Mass Air TPI. In Speed Density applications, such as TPI this cam would be miserable on the stock tune.

I know that 204/214* @ .050 is BARELY driveable on the stock (1993 Caprice)chip. 224/224* @ .050 will not even start to run on the stock tune. In a 350 TBI the 204/214* will run on the stock tuned.

 

I didn't take into account the speed density of the situatuon. Though I love tuning my SD. Quick and easy compared to the old maf.

 

I ran a B-body LT1 and F-body LT1 cam, in my LO3 on the stock tune and I didn't even bother taking it past the driveway. That is how bad it ran. It needed 12° of advance and bogged so hard it would shake the car.

 

l03 cam:

lift: .350 int./.384 exh.
dur: 179 int./ 194 exh.

lobe seperation: 109

crane cam:

lift: .407 int./.429 exh.
dur: 194 int./204 exh.

lobe seperation: 111


there isn't a whole mess of difference between the two, it's not even pushing the limits of the valve springs or anything, and considering the lack of air flow from the stock intake manifold and heads, I doubt it'd even take full advantage of the extra lift.

I dunno, I'd be willing to bet if you just let the car run for 20 minutes in your driveway before driving it it ought to compensate for the new cam enough for it to be driveable, and if you want an extra net of safety you could maybe up the octane of your gas to 89,91,93 and advance your timing by maybe 2*(which a lot of people do anyway), but even without that, it should still be fairly driveable.

I've really got nothing to say about the lt1 cam, everyone seems to agree with me on that.

also, both maf and sd tpi 305's got a small variety of cams, at least one of which was always more aggresive than this one, so I'm a bit confused as to how much of a difference that really makes.

 

My experience with the LT4 cam seems to be a little different than those stated above. (Not contradicting just stating for facts )

LT4 stock cam 446/450 lift w 1.5 rockers and 206/210 dur. @ .050.

Engine was stock LO3 with better breather, headers with full exhaust. Stock fuel pressure. Initial timing was from 0 to 8 advanced.

I could tune the chip but did no real changes.

The car ran fine...better than stock. It was not nearly as good as I could do now with it but it was completely drivable. Why this is not the same for others? Don't know but as I stated this is just my experience with the subject.

But.........with a head and intake change it was a different story.

It was not untill 2005 when I finally bought a laptop and started using winaldl and got some help with the timing table that the car runs as it should.

DM

 

Now..........." IF" I was to do any mods to an injected motor again. On the top of my list would be a laptop, a burn1 setup , a few chips, a data logging cable and download winaldl.


Just consider these as one of your first mod's

 

DM, what kinda hp numbers did you get out of that thing, if you know?

also, what did it pull to, as in highest rpm where you were still making power?

and finally, where'd you get that from? for about a week I'd decided on an lt4 cam as opposed to an lt1, until i realized i couldn't find it for less than like 260+, if i could find it.

 

HP numbers I couldn't guess?

It would pull to over 5k. Just how far I don't know as later I found out my stock tach was reading overly high. (I didn't really think it could pull to 6k now did I? LOL)

I bought the cam from Jim Pace back before I ever had the internet and found out that the LT1 cam's were about the same for very cheap. I would not buy a new LT4 cam as I did. It was about $160 when I purchased it in the late nineties.

I'd say if you want a mild cam go with the LT1 for cheap.

 

you know, a while ago I had some fun w/ desktop dyno and built up a few 305's and 350's with varying but similar specs, and found out 3 very interesting things about the 305.

1. a well built 305 had an incredibily high volumetric efficiency(something like 99.6-99.8%), far better than any of the 350s(94-96%)

2. a well built 305 had an uncanny power range, the hp numbers were never very high(I don't think got past 400hp) but they were VERY consistant, well into the 7k range.

3. most of the power out of the 305 was only realized when the cam was replaced, everything else could be replaced and it made very little difference, but once the cam was thrown in, at any point, real power began to be made.

now i realized this was a simulation, and probably wasn't very accurate, but the more in depth I get into this, the more I want to really try and see what real power can be made out of these engines.

so many people change the heads, cam, intake, whatever. I'd really like to see someone build the f*** out of the lower half of the engine, use all forged steel, instead of cast iron, and DON'T overstroke it(I tried it in the simulation, it made about 10 more peak hp, but lost all power beyond about 5300rpms), and THEN see what they can do with the top half. I'd be willing to bet there'd be a lot of suprised people out there.

sorry if that got off topic, it's kind of about cams? and tbi?

sorry...

edit: if it helps, I used the lt1/lt4 cam on the 305 and 350 for almost all builds. I think that's why I thought of it.

edit edit: I'd even go as far as to buy a racing block if I personally had the money, I think, if that simulation had any kind of vailidity to it, that this borexstroke design may just be far better than anyone really makes it out to be, if taken to it's fullest potential. that's what really got my attention out of all of that.

 

I agree!
ON the RPM part of a 305. With the right cam 6,500+ is definately possible. My stock 305 had a forged crank, forged X rods, and a dished forged piston. Guess what, it now has flattop forged pistons and is .040" over. The lower-end was balanced very precisely. I have no worries taking it to 6,500 rpm and used to on occassion. With my stock 187 swirl ports that were sitting on top there wasn't much need taking it above about 5,500-5,800. The small engine, low gear, lots of RPM combination works well for me. Give it enough torque to lug around town and the MPG is good for the power that you can make. I was making 300 RWHP through open headers, 275 RWHP through the exhaust, and still getting 18 mpg on the highway (van), plus it has enough guts to pull 4,000+ lbs trailers just fine.

For roller cam 305 blocks the ZZ4 cam is awesome. For us using the old style blocks, the L82 cam runs very strong in a 305, has good torque, and gets decent mileage. For those considering retrofiting to a roller cam, don't overlook the crane offering that I am running.

Contrary to popular belief the 305 actually likes a narrower lobe seperation angle, especially with swirl port heads. A stock vortec 350 cam in a 305 TBI has a broad, lower powerband that makes for great street performance, imo.

 

I really can't add anything to this, but it seems to be a lot of really good information.

I think we're really on our way to descovering the secret to making a genuine competitor to the 350's(possibly even as far as the lt1's) without dropping 2 grand first on exhaust and intake parts first that give fairly minimal gains, comparitively speaking.

I think at some point in the near future it may be time to make a new, even more comprehensive, and hopefully even easier to understand all-in-one sticky(possibely even website?) on how to make cheap, REAL power out of these engines, as well as cars, maybe even to go as far as a genuine full build of these cars, with real options that are proven to work, as well as mention the parts/accessories that are proven not to.

I think there needs to be a competitor to goingfaster.com's website, there's been a lot of r&d done around here since then, and it's about time someone stepped up and corrected his mistakes, and gave an even further(and perhaps less opinionated/more objective) in depth approach to the whole build.

you know, just my opinion.

 

Intake, maybe (non-ported that is) but heads...eh I would disagree. Both Fast and Dewey have motors at the 300hp mark without touching the stock heads. Refer to this thread in particular.

We like these heads now


Agreed with the exception of exhaust. Some have seen an increase in VE by up to 10% (IIRC it was Dewey, Pablo and JPrevost that recorded an approximate value).

This also, validates the simulations you see in DD. DD is indeed a tool but it is pretty accurate.


IC engines can't escape the math and provided you have all the necessary data to enter you will be amazed how realistic the results are. Every auto maker has a motor designed and modeled before a single part is cast. The engine build process only confirms their predictions and also serves as a platform their durability and manufacturing control testing/processing.


There is...it is called TGO . It just isn't fully compiled yet into one thread but I can tell you that I have been working on one "sticky" that follows a build, with data acquisition, and follows it up with track/dyno info. Stay tuned.

 

sweet.

and that's all I've got to say about that.


actually, I'm REALLY REALLY excited about this sticky you're referring to, I can't wait.

 

The stockTBI intake is perfectly capable of supporting 267 RWHP on a 350.

The exhaust does provide real gains. With only a high-flow cat, shorty headers, and a low-restriction exhaust I have recorded BLMs in the 138 range where 128 should be more normal.

Not thirdgen specific, but if you have a 2.8 TBI the gains are even more. My stock 2.8 needed 4.3 injectors after a complete exhaust system. The stock TBI computer was not able to compensate for the full exhaust system on it. My 4WD 1987 GMC Jimmy went from 20.78 @ 67 mph to 18.65s @ 74 by changing the exhaust, to headers, 4.3 injectors, and playing with the timing. The reason I mention this is the exhaust on the 2.8 S-truck is amazingly similar to the TBI F-body platform. The manifolds are tiny and restricted. The Y-pipe sucks. The cat should be sent to the scrap pile. The muffler is very restrictive and the overall size is too small for even a 2.8 (2.25"). Full length Headers with 2 1/4" collectors, a new Y pipe 2 1/4" into 3", 3" in/out high flow cat, a 3" high flow turbo muffler, and a single 3" tailpipe really woke the 2.8 up. It was not too much for a 2.8. Imagine what a 3.5" system would do for the 305. Truck 305s had 3" exhaust and were rated a full 10 HP/20 ft/lbs more.

 

I agree with you guys on both the exhaust and heads, but I've always got cost-effectiveness on my mind, and a full exhaust change can run you a grand plus.

as for the heads, I've been aware of their potential since the post came out about the flow #'s of the ported 350 swirl port variety.

the thing is, the heads are at their best when they're ported, and have larger, SS valves, not so much stock. you can pull some power out of the stock heads, but a high lift cam on stock swirl port heads isn't exactly going to create a performance monster.

just because it can still be there when real power has been achieved doesn't mean its the best choice for performance, ya know?

I'd also like to mention real quick that people seem to keep comparing our heads to vortec heads, but only in flow #'s. flow #'s really aren't what make vortecs the best, it's the heart-shaped combustion chamber that maximizes power potential on the compression stroke, as well as directing the air more efficiently. I guess I mean that it IS the flow #'s, but there's a bit more to them then that.

 

You don’t need the 1000$ exhaust (you want it though), you need the 500$ or cheaper exhaust. Headman shorties, with their y-pipe is the best bang for your buck and you can have them for about 230 shipped. I believe you can get some catbacks for as low 250$, I suggest getting the Iroc 3” “mid pipe” throwing a single exit 3” muffler on the end of that and calling it good till your ready to step up to a 4” or bigger system. If you know a good exhaust shop you could have a better Y-pipe made for the headers. I had a full dual exhaust made out of 2.5” pipe for my monte for under 250$ without the mufflers. I say you could get a big Y-pipe made for less than the cost of the headman unit. I wouldn’t write off an intake as not being worth the money. It will only show about 10-15 HP on a stock motor, but it can be worth big HP when you start approaching 300HP. My wife dropped from a 14.3 to a 13.9 with a swap from a stock aluminum intake to a performer RPM.(granted we had a holley mounted to a spread bore intake)

Swirl port heads….now that’s a debate in itself. I’m not running them, but that doesn’t mean their not a good choice for some combo’s. I firmly believe, based on flow numbers, basic engine physics and tuning both SP and non-SP motors that SP heads are best for 275 HP and lower engines that aren’t going to be spun much higher than 5500 RPM. They’ll make more torque over a broader part of your power band than std. 305 heads. Above 4500 rpm or so the conventional heads will start to have an advantage. The bigger your motor the lower this point will be. Once you start making more power, and are running a bigger cam (218 plus) then I think the conventional heads will be a better match for performance. You’ll give up torque, and efficiency for top end HP. I wouldn’t go as far to compare SP heads to vortecs, sure the exhaust flow numbers can be better, but the intake lags so far behind I don’t think it’ll matter much. Others will disagree with me, and that’s fine. Most head porters shoot for an intake to exhaust ratio of about 80%. Ported SP heads can exceed 100% easily. What does this mean? I think it means that you’ll need a single pattern cam, and that additional exhaust flow will show marginal power gains because there won’t be as much combustion byproducts to exhaust because of the restrictive intake ports. Take a closer look at the flow numbers, you’ll see a max of 190 cfm for the intake of SP heads, vortecs flow near 220 cfm. If you use vizard’s 2hp for every 1 cfm formula you see that vortecs will definitely be making more power.

If your building a torquey street motor that will get good mileage and run bottom 14’s, stick with the SP heads and save your money for vortecs or other aftermarket heads. If you are looking for more power than that, and have more time than money, I suggest picking up some carbide burs, and a set of conventional 305 heads and shooting for low 13’s with a bigger cam. Just for comparison a set of stock vortecs and a smaller (210ish) cam will run you low 13’s and a 220ish cam will get you into the 12’s.

Kdrolt has some good thoughts on the subject, hopefully he’ll be along to share.

 

could you put up a link for that? I've never seen any set of headers, much less ones that include a y-pipe, for less than 350-400 bucks, and those weren't on the list of headers I was willing to buy.

on top of that, we're looking for the end of the y-pipe to be 3", which is a bit rare among header companies, but not impossible to come by.

and finally, for my personl choice, I need a heat solution to these things, I don't want the paint to chip, I don't want them to rust, and I don't want them heating up my engine bay to oblivion, so I either need quality stainless steel, or jet-hot coatings, unless somebody finally found a company that has a decent thermal coating on them already.

if you can give me a link to something like that, then I'll believe you can get a 500 exhaust setup that's WORTH having, otherwise I'm sticking to my grand plus theory.

I mean I could always cheap out and buy some flowtech 1 1/2" headers, find some dinky y-pipe(probably from flowtech), get a test pipe and spend 150 at the local muffler shop for a better than stock cat-back, but exhaust isn't something I intend to buy twice, and in that case that's a 500 exhaust setup for nothing.

 

Suite your self, my junk headers are going on 7 years with nothing more than 2 coates of paint over the years.

You just have to decide how bad you want to "go fast" and weigh the pro's and cons. You'll get 90% of the go fast for 50% of the cost by going with cheap uncoated headers. If thats not worth it to you then more power to ya. Headman does offer coated headers for around 330$ plus another 100 for their 2.75" y-pipe. That y-pipe is a restriction, but I haven't seen a better choice for less than 300-500$.


Edit: Link added, with 5-minutes of searching

http://store.summitracing.com/defaul...h.asp&N=400143

 

I was just going to go with the hedman air headers and 2.5 y-pipe because im poor and there are no custom nothing shops anywhere around here. I figure 2.5 mandrel bent is better than 2.25 trash bent pipe.

 

that was the first place I looked, the headers/y-pipe I came up with was like 350-400 together, and it was a 2.5 y-pipe, thats why i asked for a specific link.

I'm not trying to be a jerk, I'm actually looking for headers, and if there are some that I like for cheap enough I'll go for em.

thanks if you can help me.

 

I hope they are not flowtechs. If they are you are the lickiest person in the world. My cheapo flowtechs lasted 2000 miles and never worked right from the moment I put them on. I wasted $450 on thos things (coated + kit cost + gaskets).

 

Knock on wood my Elecrocks have lasted 11 years. I think they were built decently and with a 2.5 into 3" y pipe.

I agree with BM on the single 3" in and out. I have mine tucked up out of sight and it does sound good. (At least to me )

DM

 

No their headman's, 3 of my friends have the camaro version and they seem to fit the best compared to the edelcraps, and hookers. I know for a fact that they are the easiest to change plugs on. One of my friends has the ceramic coated version and he likes them alot. They do keep underhood temps down, but at a cost. The coated ones were around 350$ compared to 130$ for the uncoated version.

The headman y pipe sucks, but it is madrel bent and it's the best you can do for 110 bucks. Like I said 90% of the performance for half the cost. I really think that most cat backs are overpriced for what you get. I would just go with an iroc mid pipe and single inlet and outlet 3" muffler or save my money for one of the 4" setups. Luckily I have room for duals, I also run an x-pipe with the muffler dumped at the rear axle.