zeeboost Posted February 9, 2004 Share Posted February 9, 2004 This post is pretty much a question to those who drive Zs with carbed Chevy 350s or have had previous experience with them. I'm concerned of the reliability issue of having a carbed 350 and needing it to drive every day, seeing as how it's my only car. I will rely on this car to get me to college, work, and then safely back home without overheating or leaving me stranded. The engine is not a monster, but I'm pushing around 400 hp, and sadly yes, it is carbureted with a brand new Holley Street Avenger 670. I know that these engines are dirt cheap and are a penny a dozen, but can you actully put your trust it? I just need reliable transportation for about 5 years -- this includes frequent oil changes, plug changes, timing chain, etc. I will not neglect this engine, I just don't know if I can trust it, and I'm wondering if buying a second car wouldn't be a stupid move and a waste of money. Again, I'm just asking you about your previous experiences with the reliability of a 350. Thanks for any help or advice. Quote Link to comment Share on other sites More sharing options...
Mikelly Posted February 9, 2004 Share Posted February 9, 2004 Don't know about your area, But I was able to drive my SBC 383 stroker Z in washington DC rush hour (Some of the worst traffic in the world) traffic in summertime without much fan fair once I got the heatsoak issues with the starter, and the heating issues (Electric fan fixed it) resolved... I'd have driven it anywhere. Mike 8) Quote Link to comment Share on other sites More sharing options...
Tim240z Posted February 9, 2004 Share Posted February 9, 2004 I don't see why you wouldn't trust it...the SBC is one of the most reliable powerplants out there. Just look at how many old Chevys are still on the road, and by the looks of some of them, have not had much in the form of maintenance either.... Tim Quote Link to comment Share on other sites More sharing options...
Phantom Posted February 9, 2004 Share Posted February 9, 2004 It's as good as the guy that put it together. Let's face it - that was what all the cars ran back before 1970 with a few exceptions and they seldom had overheating problems. If you've done a good job of matching the components then there should be no problem. Also, whether it's carbed or FI makes no difference when we're talking about cooling. Lot's of FI cars out there with cooling problems - fortunately mine is not one of them. Quote Link to comment Share on other sites More sharing options...
Chaparral2f Posted February 9, 2004 Share Posted February 9, 2004 you should have no problems. after all carbed engines have been the norm since the earliest cars. My past experience seems to show that engine life is directrly proportional to the weight of the right foot. Quote Link to comment Share on other sites More sharing options...
COZY Z COLE Posted February 9, 2004 Share Posted February 9, 2004 First of all it's smart to have more than one operating car, I don't care what the engine is in your main car!! I have 4 Z'S but let's address your question about the 350 sbc reliability. In my 75 280Z I installed a HOLLEY 144 blower with a 700 cmf HOLLEY carb built for superchargers. Of course I have an electric fan, alum. radiator, and larger water pump. I drive this car every day when it is not raining . Sure I had initial issues, but correct.... matched parts and detailed engine build is an important key to any high proformance engine. I expect this car to be running good for years to come with proper care!!!! LARRY Quote Link to comment Share on other sites More sharing options...
Pyro Posted February 9, 2004 Share Posted February 9, 2004 Assuming your engine doesn't have a cooling problem. The biggest problem you will have is cam and lifter wear. Cams that make 400 hp will not have a 100K mile lifespan like a stock cam. High and quick lifts will kill the valve components quickly. Even roller rockers and roller lifts die quickly under high performance conditions. To get 100K+ miles from a stock valve train, engineers design soft ramping lobes and weak springs. In extreme cases, I have seen people try to drive 0.700" lift, roller, big block chevy engines on the street but only to eat up the entire valve train after a few thousand miles. I would guess that you could get 25K to 40K miles from your valve train components (springs, rollers, cam, lifters) when using a "400 hp" small block cam. Furthermore, if you drive a lot on the highway, keeping the rpms low will extend the engine life. So a 3 speed automatic car with a 3.90 gear will last half as long as a 5spd car with 3.55 gears. Quote Link to comment Share on other sites More sharing options...
zeeboost Posted February 10, 2004 Author Share Posted February 10, 2004 If you've done a good job of matching the components then there should be no problem. The biggest problem you will have is cam and lifter wear. Cams that make 400 hp will not have a 100K mile lifespan like a stock cam. My current setup is mild. It's a stock bottom end, stock dished pistons, Holley Systemax II aluminum heads, victor jr intake, Msd ignition, Rhoads lifters, 280H comp cam (230 ; 480/480), headers, 8mm wires, and I'm sure I'm missing a couple of other small things. So with that cam setup, how long do you think I should wait before I change out the valvetrain components? The cooling system is a griffin 26 x 19 radiator with dual electric fans, and when I was referring to problems with carburetors, it was mainly directed towards their cold start issues and having to tune them...although I have heard that Holley's carbs are easy to tune. Furthermore, if you drive a lot on the highway, keeping the rpms low will extend the engine life. So a 3 speed automatic car with a 3.90 gear will last half as long as a 5spd car with 3.55 gears. I'm usually running around 2000 rpms on the highway. I do have a 3.9 rear, but I also have the advantage of a T56's wonderful overdrive, so it compensates for the rear ratio. Thanks for the replies...any others want to chime in? Quote Link to comment Share on other sites More sharing options...
Guest Blazer406 Posted February 10, 2004 Share Posted February 10, 2004 I don't think engine reliability will be a problem...... and I will echo what everyone else says.... "if you keep it cool". I would be more concerned with drivetrain components breaking...... cause if you got 400 HP ..... at some point you are going to mash it hard...... and if you have some decent sticky tires...... or decide to go to the strip (let's say) with a friends ET Streets....... stuff can break...... and you sure don't want that..... especially if it is your primary mode of transportation. I would highly recommend a sub $1K clunker as a standby...... and in case something breaks on the Z....... you can make a call to the insurance company... crank up a months insurance...... and viola.... you now have a month to fix your ride. You can still drive the Z everyday ... but if it breaks.... you have a backup. just my 0.02 Quote Link to comment Share on other sites More sharing options...
QWKDTSN Posted February 10, 2004 Share Posted February 10, 2004 I trust everything about it except the temperature. Quote Link to comment Share on other sites More sharing options...
Guest zfan Posted February 10, 2004 Share Posted February 10, 2004 HELL YES..We built it, no shop this time Purres like a kitty! 185 temp all day long! Mike Quote Link to comment Share on other sites More sharing options...
Guest Nic-Rebel450CA Posted February 10, 2004 Share Posted February 10, 2004 Well, here's a tribute you cannot refuse... lots of people will say Hell Ya I trust my SBC, I change the oil regularly, take really good care of it.. yadda yadda yadda However, I have to admit that I dont take the greatest care of my engine. I dont change the oil exactly when I am supposed to, I have 4.10 gears and drive at 4500 RPM on the freeway to and from work (about 25 miles each way). I have a flex fan that is much too small and isnt close enough to the radiator. And all this is moving my 4500lb+ 65 GMC. (Not a light load like a Z). My 350 runs hard, strong, and is unbelievably reliable. In contrast, I have a little Honda with a 2.0L DOHC FI engine that is supposed to be super reliable and I try my best to keep up with maintenance and that thing is just breaking in one way or another no matter what I do. I love my Chevy 350! Quote Link to comment Share on other sites More sharing options...
Pyro Posted February 10, 2004 Share Posted February 10, 2004 I use the Black Magic fan on my Z and it runs 190 to 200 around town in the summer (south Texas). If your fans pull enough air you shouldn't have a problem. What also makes an engine overheat is the hot air stuck in the engine compartment. If the hot air can't get out then flow over the radiator is reduced. IMHO, 50K is about all you can expect from a 280 comp cam. But, cams are pretty cheap and easy to change. However, roller rockers also wear out which starts adding up costs. But that is what you can expect when high performance parts are used. Your low rpms on the highway is a big plus! I'm sure your car will do fine. Just take it easy. Quote Link to comment Share on other sites More sharing options...
Guest greimann Posted February 13, 2004 Share Posted February 13, 2004 I think a more important question is, How much do you trust your workmanship? I drove my V8ZX daily for 8 years, and the "Chevy" part of my install never failed. The "Dave" part of it failed bigtime several times. It was mostly because I was an igit or lazy about something. #1 failure - Car came to a dead stop on the 405 freeway, at rush hour, in a construction zone with NO shoulder. Almlost got rear ended by a big rig . Cause: positive lead to distributor dropped off because of loose spade clip. #2 failure - Slave cylinder bracket broke on the street, about 10 miles frome home. Had to drive the car home clutchless (another thread altogether on the technique ) Cause: Used aluminum instead of steel. #3 failure - Engine fire! . It was quick. 3 seconds for the following sequence: Smelled fuel, saw smoke, flames shooting out of the DEFROSTER vents :flamedevil: I knew the heater was good, but this is ridiculous! Cause: no bead on a joint between a steel and rubber fuel line. The rubber fuel line pulled off the steel line and sprayed raw gas on a hot exhaust manifold. That was an interesting day. Moral. No shortcuts. Be careful out there! Quote Link to comment Share on other sites More sharing options...
zeeboost Posted February 14, 2004 Author Share Posted February 14, 2004 Thank you all for the replies. Griemann -- I've always loved your zx -- it's pretty much one of the only 2+2s that I wish I had. I'm a huge fan of EFI and I was leaning towards the 4di setup just like yours, but I've never calibrated an ECU and I figured that I would end up screwing up somewhere which would cost me more in the long wrong, so I figured I'd just keep it simple and get new carb. As far as your question goes, I do trust my work, but only because I'm not going the cheap route with this engine. Plus, I have some other more experienced mechanics keeping a look out on this thing to make sure I'm not overlooking anything. My heads were just pressure tested (in the machine shop said they tested fine) and were shaved down .005" due to a small O-ring groove from the previous headgasket. I bought the ARP headbolt kit (which says to torque aluminum heads to 60 lbs., but that doesn't sound right to me) and so on and so forth. Pretty much the general answer seems to be: "Sure, the 350 is a great engine as long as you don't dog on it", which still sucks for me. While I do not plan on abusing the engine 24/7, there are some cars that I will have to put in their place (on an empty, deserted, 4-lane highway of course ) One of the cars being a 90 LX with a crate 5.0, bigger cam, intake, exhuast, 4.11 rear, fat tires, and 125 shot of N20 -- I'm worried about that race -- I'm gonna film it and post it up as soon as it happens. Anyways, I guess the original question should've been, How durable is the sbc?" Is there any kind of preventative maintenance I should do for heavy driving? I've always heard from my uncle (who's owned several t/a's in the past) that the most important thing I need to do is make sure I do frequent oil changes. I know that I need to maintain other things, but are there any key tips/suggestions you would have? Once again, thank you all for the replies. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.