Help! My Chevelle's been undriven for 5 months! Can't find halp anywhere. Ok, I bought this punched out 350 making 497 HP on the dyno. Crane cam, hydraulic lifters, black pushrods, 1.6 roller rockers, valve springs, Manley valves, Pete Jackson gear drive, etc. Ever since I put it in the car, I've occasionally heard a noise that I thought was valves that needed adjusting. It ran OK. Well, the noise kept getting worse, and then one day it started running terribly, and sounded like a rocker arm had com off or something. Definitely sounded top end. Well I took the covers off and the whole top end seems tight. No broken springs, no missing keepers, no escessively loose rockers. I've have adjusted the valves numerous times. When the car is cold, it starts and runs good, but I hear the rattle. Then when I go down the road, it gets worse and runs bad. The car's making great oil pressure. Timing is advanced to 30. I can't tell where the noise comes from. When I listen it sounds like it comes from both valve covers. It's a rattle just like a loose rocker or maybe even detonation. I've backed off the timing with no change. Strange because also since installing the engine I've had problems with hot restart. The starter can't turn the motor over and it sound like the timing's way off. I have to let it cool before it restarts. I have an MSD 6A and I have it on a swirch so I can build oil pressure before start. Even with no ignition this happens. I've changed starterd and timing with no avail. Do I need a high torque mini starter or something (currently using junk from Advance Auto, but even a new one didn't work). Previous owner is no help. He said he's never had these problems. Please give recommendations, I can't use my car!!! ('72 Chevelle in majestic blue, 8.49 et). Thanks!!! jad006@bridgewater.edu (I don't get on here very often).

Timing at 30º ???? is that initial? 497HP with a hydraulic cam? is it a flat tappet? Try setting your timing at 12º BTDC with the vacuum advance disconnected and plugged at idle. Check your plugs and wires. are you sure the valves are set right? If they were to tight you would here sounds and it will run bad

500hp from a hydraulic cammed 350, I don't think so. Why did he sell the engine? How much did you give for the engine? If it won't crank with the ignition turned off I doubt its the timing. The starter will not stop the top end noise you speak of. Why don't you ask the previous owner who built the engine and go from there? How much compression does this engine have? Might be a carburetion problem? leaning out as it warms out? sounds like you bought someone elses headache.

Timing is initial. This isn't good is it. My old motor was always set at 35 and ran awesome with no noise. When I put the new motor in I went with the old ignition and timing. Is my problem preignition? If so, have I caused damage? I only put around 50 miles on it. It still runs great when cold, it just makes the noise. Carburetion, plugs, wires, etc all seem good. If you could explain the cam thing I could tell you what it has. I don't understand tappet and flat tappet. It has Comp Cams 1.6 roller rockers. I have not seen the cam or undeside of the lifters but looking down through the pushrod holes the tops of the lifters look like the typical factory hydraulic oil lifters I am used to seeing. I may have gotten myself into more than I bargained for. Thanks for the advice.

also I'm using an MSD 6A, a Blaster 2 coil, and a gutted HEI -- no vacuum advance. Additionally, I know the starter and top end problems are unrelated, I was just seeking advice on both. It seems to me the starting problem is the starter, but it just sound so much like wrong timing and a new starter (the same one the previous owner was using) did no good. However, the timing may very well be different (too far advanced) than it was when he had it. Thanks again

Hi...does the mechanical advance still work? If so you want some where between 34-38º total timing all in b4 3200rpm..so if your mechanical is advancing 20º you need to set the initial at 14-18º. With a large cam(assuming you have) it will like more advance at idle..but not like it after 3200rpm..2 ways to get around it...first lock out the distributor..so you have no advance..then set it to 34-38º..this is for a strip only ride mostly or you can limit the mechanical advance to around 15º..then you can set the intial to 19-23º. Its very very hard to make those HP numbers with a 350. there are 4 types of cams..hydraulic flat tappet(lowest HP) hydraulic roller(next in line) mechanical(solid) flat tappet(can rev pretty high) and solid roller(the bad mama jama)

Depechevelle:
I just put a new 355 in my 69 malibu. My engine builder is est 500hp. This is with a hydraulic roller, but I'm running 12.65:1 comp, a very big cam,race gas only. You can easily get that hp out of a 350, pump gas- now that's another story. This engine replaced a ZZ4 and I ran into very similiar issues. This motor must be hot! What are you using for convertor; I had to step up to a 3800 stall. Your timing is the first thing I would change. Like others have stated, 18 initial and 36 total. I had mine recurved with no vacuum advance, the engine doesn't create much vaccum anyway. I was using a 650 speed demon vs and it wouldn't idle at all. The new mighty demon 750 mech solved my carb issues. I tried to reuse my stock starter...no way, the high torque mini starter...problem solved! As for the top end noise, have you adjusted the valves warm ? None of the other things mentioned would help valve train noise, quite inerestin. Feel free to e-mail barry@eugeneforestproducts.com ,if you would like any more info.

Thanks for all the help. I'm running a 9" 3500 TCI stall and a 780 Holley double pumper w/ milled choke horn and a 1" spacer. It does have a large cam and compression is supposed to be around 11 or 12. I think changing to a mini starter will solve my starting problem, but my block takes a staggered bolt pattern starter, and I can't seem to find one of these. They all seem to be of the inline pattern. Any suggestions? Also, why does my current starter crank the engine fine every time when it's cold, but rarely when it's warm? I still don't know about the noise and poor running. Why would it start and run OK cold but still make the noise, then get worse and run bad as it warms up? Could a lifter be losing pressure as the oil thins out or something? I've pulled the covers with the engine warm and all the valves/pushrods/rockers are tight. Any tips on adjusting roller rockers (they have a 5/8" bolt with a hex lock bolt in the middle). Can/should these be adjusted while the engine is running? The noise is a strange one that to me sounds too low to be a rocker/valve but too high to be a rod knock/piston slap. What does detonation sound more like? I'm stumped. Right now we're having snow, but as soon as I can I'll back the timing down again - the only thing is, I've tried that already when it was running poorly and it didn't help. Plus, I'm afraid to drive the car anywhere b/c the starter won't restart it once hot. Can anyone help with my starter issue? I can only find one online that's for that bolt pattern but it's not a mini-starter.

unlucky for you it's a staggered bolt pattern.

CVR starter p/n 171-5323OS (Jeg's sells 'em) is what you're looking for. my buddy's got one on his blown 355, works great and can be adjusted to provide more clearance from the headers. you'll need that to fix your heat soak problem with you're current starter. it's the typical problem on Chevy's with headers, that's why it's hard to start hot also if the battery's been relocated to the trunk, make sure the cable to the starter is a large enough gage.

search on this site for the procedure to adjust lifters on a hydraulic cam, it's been covered tons of times. hydraulics are adjusted when the engine is off.

detonation will sound like rocks rattling around in a coffee can. with that high of a compression ratio, you might require higher octane fuel. the CR on my BBC is 11.43:1 and i use 101.5 octane with no problems. (with 38 degrees of advance!) if you're timing's way advanced and your octane is too low combined with high compression, it's almost certainly going to detonate itself to death.

Battery has been moved to the trunk using 6-guage wiring. I had no problem with this setup using the previous engine.

Thanks for the starter p/n. I think I'll try the new starter, adjusting the timing, and higher octane fuel and see what happens. Just one last question, will detonation cause the problem of some valvetrain noise and ok performance with a cold engine but lots more noise and poor performance with the engine warm? Like I said this has come on gradually over the last 50 miles or so. Thanks everyone, I appreciate the technical aspect of Team Chevelle and everyone's willingness to help a fellow enthusiast. Keep it up!

#6 gauge wire is too small....especially with high compression and timing problems. I ran a 1/0...probably over kill but its better to be too big than too small..If your valves are not properly adjusted"they all feel tight" you will have performance problems.. heres a link on how to adjust them http://www.cranecams.com/master/adjustvt.htm

depechevelle , with your compression ratio, you may want to try some race gas. If your engine was deonating, it would cold as well. I would really change your timing and run some better gas. The covers for the starter are replaceable, mine had a straight bolt pattern. A great starter guy is Rick @ ALLWAYS JAKES in eugene, or. 541-338-3938. He could totally set you up.My old starter left me in front of the staging lanes, never again will that happen.Give Rick a call, he's a nice guy.

Here is part of a post on this site (See Carb Mods), from one of the modifications we did to our GM 350/330 H.O. Crate Motor. In our signature, you will see what else has been done. When we had the heads modified, we used the posting from Gary at GMPP to make sure we didn't ruin the "Effects" of the Vortec Heads.

Our final dyno numbers were 467 @ 6,100 RPM, Unocal 76 100 octane race gas, and the HP Curve never dropped off. We wanted to go even higher in the RPM Range, but the engine builder guaranteed the engine (Within Reason). He insisted that we use Dan @ Dan's Driveline here in Las Vegas for the dyno session, and the best timing curve was at 35 degrees.

Remember, this motor was built for high/top end only, as that's what you need at El Mirage and Bonneville (No drag racing here).

Let us tell you, it is well worth it to sit in and help on one of these sessions. Dan knows more than we could ever imagine, and he taught us some great ideas in engine building.

Now it's time to add the Nitrous!

We (I) did learn alot about engine building during this process, and the dyno guy (Dan of Dan's Driveline) taught me how to rebuild and modify an Edelbrock Carb (You actually port and polish it). With his modifications, we basically built an 850 cfm out of a 750 cfm. After this modification, the HP increase was 31 HP, and now we have been taught how to curve the Accel HEI. It really is fun, and we both enjoy the "Challenges".

Hope this helps somewhat in your problems.

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Almost Forgot!

When we added a 1/2" aluminum carb spacer to duplicate the nitrous plate, we lost 5 HP!

Go Figure?????

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