73-87chevytrucks.com
73-87 Chevy _ GMC Trucks => Performance => Topic started by: Layne on May 20, 2009, 05:22:44 pm
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I'm running a lunati bracket master II. I just broke it in and put a synthetic blend in without realizing it. Lunanti says not to run synthetic or a blend in there. Am I going to have any problems, or do I have to drain the oil again?
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I would dump the oil and run a conventional 10w30 to break it in.
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The main problem that leads to cam failure with oil is the lack of zinc,you should use a zinc additive during break in but i don't know if it would do you any good now.
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I've decided now that with each oil change I'm going to add a bottle of GM EOS. Get it at most any GM dealer I would imagine. Then I can run whatever oil I want and not worry about how they are reformulating it.
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I remember when I worked at a GM dealer and they couldn't give EOS away. I had cases of it given to me by the parts guy. I'm down to about 4 or 5 old bottles. Ford also makes one too that I have a few quarts of.
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The EOS was rummored to have been "reformulated" a couple years ago by an oil analyst on another forum I belong to, don't know this to be fact though. I've been using Rotella & ZZDP (a couple guys from the Buick GS club came up with it). No short term way to know what is really the answer...if you had a fleet of flat tappet cam engines, you could gain some good knowledge. Lorne
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GM EOS is a reformulated version compared to sevearl years ago
Alos when I was working in a Ford dealership they actually stocked GM EOS and GM assembly lube because they said it was better then their own, I bleieve sever TBSs mentioned using the GM versions also
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I've been hearing alot about this stuff lately.
http://www.kirbanperformance.com/product/445/ZDDPLUS+4-OUNCE+BOTTLE+%281%29+%237176.html
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Never heard of that stuff before but their description calls it zppd instead of zddp and says roller rockers not roller cams. Who wrote the description? Their secretary? lol
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Sorry Guys, That's the stuff I've been using ;) Lorne
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I,ve always used a good 10w30 oil and used zinc additive from crane cams for break in of cams or a rebuilt motor.After a couple hours run time I drain the oil and change the filter and use Royal Purple.
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Never heard of that stuff before but their description calls it zppd instead of zddp and says roller rockers not roller cams. Who wrote the description? Their secretary? lol
LOL. That's just a dealer. So I wouldn't be surprised if a secretary wrote that.
Here's the company's website: http://www.zddplus.com/
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Man, what do you trust anymore eh? If EOS has been reformulated too (presumably not for the better) than I might just buy the CompCams break-in lube additive. I was using Rotella as well but I've been hearing that's going to be reformulated too as they tighten down on diesel engine emissions and such. Hard to know what to believe. At least (I hope) I could trust that CompCams (or similar) would keep their stuff the same since it's made for exactly what I'm concerned with: wearing down a flat-tappet lobe on my flat-tappet cam using 'modern' engine oils.
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So, uh my 305 blew up the other day. I did find a sbc 400 for $200. I was told by a friend that my carb prolly gas soaked my oil, so my cam problem's irrelevent. Lol. Cam's trashed too, so I'm looking at another lunati. Oh yea my carbs a holley 750, and my friend says thats even too big for a 400. Should I get a dif carb or can I kinda tune it without the engine running?
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I am running a holley 750 on a 383....no problems what so ever
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Don't be afraid to think a 600 will be too small for a 400. It takes fairly deep breathing to really require a 750. What heads do you plan to run on the 400?
What happened when the 305 blew up? Was it just running okay and then quit or was it a high-RPM run and then boom! lol
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I would run a 750 Holley on a 400 or a 383, no question. I also have it on pretty good authority that, so long as proper attention is paid to atomization, they'll work very well on a hi-perf 350.
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Doesn't Job Gibbs make a oil that's supposed to be good? Joe Gibbs Driven - http://www.joegibbsracingoil.com/whyuse.html. I read about a few racers who use it in their rides.
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Event, do those Vizard books you have contain a chart with CFM vs displacement? I've been told that even with a volumetric efficiency of 100%, a 350 doesn't even need 600 CFM. 750 might still be even more than a 400 could ever consume. I don't have a reference source handy to me though.
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Understand VE is going to change throughout engine rpm, engine load, temperature, humidity etc. A carburetor rated at 850 CFM will work just fine as long as it is tuned correctly. The cfm rating is a max flow rating. Proper jetting and metering is all you need.
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That's all true, but VE will also never go past 100% either unless it's a pretty hairy race motor and part-throttle conditions lower VE at that moment even more. I'm not trying to debate theories or anything about VE and how real-world conditions actually dictate things. I know of this one engine builder who is constantly saying how to go smaller on carbs, heads and cams to produce better power down low for mild motors. He likes 525 cfm Holleys on most any sub-450 HP small block. To listen to him at first you have to wonder, but to keep listening it sounds like he is speaking from experience. But anyway, I digress a little. I wouldn't do a 750 personally unless I had a more radical motor but that's just me. QJ's are 800 CFM and came on low-power, short-revving smog motors right? Go figure.
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Event, do those Vizard books you have contain a chart with CFM vs displacement? I've been told that even with a volumetric efficiency of 100%, a 350 doesn't even need 600 CFM. 750 might still be even more than a 400 could ever consume. I don't have a reference source handy to me though.
Yes there are general guidelines on carburetor sizing in several of his books. But he places most emphasis on venturi size and booster gain relative to the engine combination. To illustrate this he has used carefully blueprinted 1200+ cfm 4500 series carbs on both street and race 350s with very positive results.
Grab a few of his books. He seems to be brilliant on the subject (fuel mixture preparation seems to be his specialty).
http://www.amazon.com/How-Build-Horsepower-David-Vizard/dp/1884089143/ref=sr_1_2?ie=UTF8&s=books&qid=1243984023&sr=8-2