V8Astro Captain

iTrader: (1)

I'm shopping for cams and I have two choices.

One is (all specs at .050") 214 / 224 dur and .442"/.465" lift 112* lobe sep.

The other is 224/234 dur and .465"/.488" lift 114* lobe sep.

I want the engine to idle decent and not run too rich either. I think the second choice may be too big, but I thought I would post it just in case someone has pulled it off with no big problems.

Will I need new valve springs for either? The engine only has 6K miles on it.

NJ SPEEDER

with a 350 both of those cams are actually pretty small. you will have a great idle and lots of vacuum. i would take th esecond one or even go a step up from the second one.

later
tim

V8Astro Captain

iTrader: (1)

Is that second cam gonna work with the TBI (after much tuning)?

My friend has a similar cam in his TPI T/A and it doesn't work for ****. I mean, the ECM goes hog wild at idle and runs stinkin rich, even with the Ed Wright chip.

fast_broker

iTrader: (1)

Those are the Summit/SIS $79 cam/lifter kit specs. I suppose they would both work ok in that the bigger cam has a higher Lobe Sep which should help. I guess you have to write down/figure out the cam overlaps at .006" and at .050" lift and make a decision from there, ie, more overlap usually = less vacuum, which may hamper EFI tuning.

I thought you just changed cams??? what are you running now and why are you unhappy with it?

V8Astro Captain

iTrader: (1)

Nope. I'm still trying to figure out which one to get! You see, my friend with the T/A totally flopped when it came to matching his cam/heads/intake/gears/stall and now his car is slow as hell. I didn't want to do the same thing.

fast_broker

iTrader: (1)

What did he do, what is his combo AND

what is the head, intake, exhaust combo you have to work with. If you are to make changes in heads/intake etc, what will they be?? TBI, I presume... Most importantly, what do you want out of the vehicle?

cid
mileage a concern or don't care
top-end drag torque OR
bottom-end tow torque OR
somewhere in the middle
highway cruise rpm
to be PROM modified???

Most mismatches are viewed as such by a severe loss of low-end torque and throttle response, whereas they may perform quite well on a dyno or a WOT 4000rpm+. This isn't a mismatch if the guy wanted top-end monster power. If he built the SBC in his tow truck, it is mismatched to his application and desires, not necessarily mismatched parts.

PaulD

Hi Captain,
I have read your posts for awhile now. It seems we have crossed many of the same problems. It's fascinating as hell to me to watch you get that green barn to go fast!

My .02 on the cam is to stay with the milder one or even milder. I have a Comp Cam 206°/210°, .450/.480 which works for me. I also have the 3.42s and a 700R4. I gotta believe you're looking for street performance with that barn. If you were planning a full time racer, I'd use the longer duration. The problem I have with the TBI is running out of fuel injector capacity at higher RPMs. You may have a plan around that with your modified TBI if you are also planning on more injector flow.

Most cam manufacturers will have a RPM range for their cams. They really do this for a reason. It really bites to tear down, replace and reassemble and not get what you expected.
Figure out how you want to drive and pick the cam from there.

V8Astro Captain

iTrader: (1)

Fast_Broker: Yeah he is trying to use a huge cam with 2.73's and stock stall with a stock TPI.
Mileage went right out the window the second I put the 350 in Not really, in fact, it didn't change at all. But it doesn't matter to me anyway.
for me, I want power somewhere in the middle, like 2000-5000 preferably. I cruise on the highway at 2000-2100 rpm. Right now I have stock heads (that will be taken care of in the future), Holley Pro-Jection intake and 2.5" single exhaust with a Flowmaster 2 chamber. I also bored out the TBI to 48mm. If needed, I can get 3" single exhaust no prob. I've been burning my own PROM for a couple months now and am confident I can get a new cam dialed in. The rest of the mods are in the sig up top.

Paul D: hehehe, barn. Yeah its fun blowning the doors off rice and other posuers like that. My parents affectionally named the 'Stro "The Hurtling BreadBox".

Right now, unless someone can think of a good reason, I think I'm gonna do the smaller one. I may need to do some light towing in the future, so a high-end cam is not going to be good.

AJ_92RS

Well right now I'm building a 350 for my RS. I've decided to go for more tire roasting torque.

I used to have a '74 Camaro with a SB 400 bored .030" over. It had the 350 #462 heads, D/P intake, and a solid cam that was 244* Dur@.050" with .510" lift, a 2500 stall TC, and 3.90:1 gears. Talk about a torque monster So now I'm used to it.

Just an FYI, also had a '72 Nova using those same heads, same cam, but a S/P intake, with a Muncie M21 and 3.73 gear behind it. It had no where near the low end grunt that the 400 did. I liked it, but not as much as the torque. The torque is much more fun in the street. So I'm using that same cam you're thinking of going with. The 214/224*@.050" dur. and the .442/.465" lift.

I had originally ordered the 204/214, .420/.442 cam, but I did want a little more top end HP. So I called and changed the order.

Anyway, the two choices that you are posting aren't gonna make THAT big of a diff. in the way the van acts as far as acceleration, idle, drivabilty, etc. Only because of the increased LSA.

Just keep one thing in mind though. Even the smaller cam of those two, is coming real close to the limits of retainer/guide clearance of stock heads. As well as the pressed in studs being yanked out, and the coil bind of the stock springs. I only say this 'cause in your sig, you don't mention that you have aftermarket heads.

Even if your heads are the Vortec heads, it'll still be pushing the limits. It's times like that where you gotta really start checking clearances. Otherwise the engine will check them for you, and that's not always good.

From what you described, it sounds like you should stick with the smaller of the two, or maybe even get the .420/.442 cam, only because the Astro weighs a little more than a Camaro, and you'll need that low end grunt to get that monster moving!!!

AJ

V8Astro Captain

iTrader: (1)

Alright. I have stock heads right now And I don't want the engine double checking ANY clearances.

Thanks for the input on the smaller cam. Will I feel a 204/214 cam over the stock one? I mean, will it be worth it? Then again, I think the factory cam is 800-3800 rpm

fast_broker

iTrader: (1)

I'd go with the 214/224. It'll get you about 300-350hp in a properly built motor and should net you more peak torque thatn the 204/214 without raising its peak rpm point to an undesirable level. Use a DP manifold!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!