Performance cam??????
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Performance cam??????
Hey, I’m looking for a cam that will give me a little extra power without sacrificing reliability. I sill have all the original parts in my motor and even though it only has 30,000 miles on it all the parts are 23 years old. So I was wondering if I could get a cam that would not stress the motor to much and would not be so aggressive that it would effect my idle. Any help would be great.
The Evil Twin
Joined: Mar 2001
Posts: 9,296
From: Seattle, WA
Your low mile engine will be fine. Its not so much the cam but higher compression that stresses the engine. That's why you don't raise your compression on a higher milage engine.
As for reliability, you're probably talking about not breaking your valve springs. Stick with .450 lift That is pretty standard for most performance cams. 260 or 262 duration is usually the lowest step in cam duration that will raise your power in all rpms. (still keeping good torque and a smooth idle) 262/272 duration would also be fine. (262 intake 272 exhaust) A 272/282 or higher duration cam will get into the point where you'll notice that the rpms have to get up to 2500 before the power starts kicking in. The idle will still be fine; but the manufacturer suggests a higher compression engine with that cam.
Crane Cam makes the L-series still. Their "Stage 1" cam is what I'm suggesting you get. It might be cheaper from Motorsport but you can check out Crane Cams to see what they got.
Stock cam is 242 duration and .420 lift I believe so you can see even the 1st stage is a nice increase.
On all performance cams (even a stock cam) put in a new timing chain and set the upper sprocket to position #2. This will advance your cam 3 degrees. This makes an increase in compression slightly at idle and shows more power in all rpms for most every street engine. If you have a shaved head, set it to #3 position unless you already compensated for the head shaving. (cam tower shims; ect.)
For your low mile engine, you might get away with just a new chain, but you can also buy the whole timing kit that includes the chain, two chain guides, chain tensioner, and two sprockets. From importedcarparts.com look up the 1970 240Z and buy the whole kit for $54. It is a Japanese made kit with Nissan part numbers. Very cheap and a good item. They don't list it for the L28 but it'll work still. Same block height.
As for reliability, you're probably talking about not breaking your valve springs. Stick with .450 lift That is pretty standard for most performance cams. 260 or 262 duration is usually the lowest step in cam duration that will raise your power in all rpms. (still keeping good torque and a smooth idle) 262/272 duration would also be fine. (262 intake 272 exhaust) A 272/282 or higher duration cam will get into the point where you'll notice that the rpms have to get up to 2500 before the power starts kicking in. The idle will still be fine; but the manufacturer suggests a higher compression engine with that cam.
Crane Cam makes the L-series still. Their "Stage 1" cam is what I'm suggesting you get. It might be cheaper from Motorsport but you can check out Crane Cams to see what they got.
Stock cam is 242 duration and .420 lift I believe so you can see even the 1st stage is a nice increase.
On all performance cams (even a stock cam) put in a new timing chain and set the upper sprocket to position #2. This will advance your cam 3 degrees. This makes an increase in compression slightly at idle and shows more power in all rpms for most every street engine. If you have a shaved head, set it to #3 position unless you already compensated for the head shaving. (cam tower shims; ect.)
For your low mile engine, you might get away with just a new chain, but you can also buy the whole timing kit that includes the chain, two chain guides, chain tensioner, and two sprockets. From importedcarparts.com look up the 1970 240Z and buy the whole kit for $54. It is a Japanese made kit with Nissan part numbers. Very cheap and a good item. They don't list it for the L28 but it'll work still. Same block height.
Guest
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Hey bleach, how hard is it to change the came shaft and chain with the engine still in the car. I have helped a couple of friends completely rebuild their engines, but that was with them out of the car. I was also wondering if you would have any idea how much power gain I would get from one with duration of 262/272. I’m just wondering if it is really worth the cash. Thanks for the help.
Ryan
Ryan
Guest
Posts: n/a
Bleach where are you getting your cam info? The stuff I have seen does not indicate the stock cams are nearly that large.
http://www.geocities.com/bruskiz/ZCamSpecs.htm
Check this site out, and see what you think.
http://www.geocities.com/bruskiz/ZCamSpecs.htm
Check this site out, and see what you think.
The Evil Twin
Joined: Mar 2001
Posts: 9,296
From: Seattle, WA
Ok, so I said I believe it is 242 duration and .420 lift off the top of my head.
Looks like an L28 according to that page is 240/248 duration and basically 0.409 or lets say 0.410 lift.
I really wasn't that far off for the stock cam.
I have no dyno numbers but the cam lets the engine breath in more air. To maximize the potential of a cam you should open up your intake, increase comrpession a little, and open up the exhaust. You might want to also make sure your carbs are big enough to put out enough fuel at high rpms or for a 280ZX modify your AFM to put out 3-9% more fuel to richen things up. They all work together. With just a 1st stage cam on a stock engine I'm guessing you'll get 8-12 RWHP which is more than any other single mod will do for your engine. It should also improve midrange torque. But more like 25+ hp if you do all the other modifications together and get it done right.
I have yet to see a well built fuel injected engine run on a dyno... anyone else? (I'm not talking about Datsun race cars)
Looks like an L28 according to that page is 240/248 duration and basically 0.409 or lets say 0.410 lift.
I really wasn't that far off for the stock cam.
I have no dyno numbers but the cam lets the engine breath in more air. To maximize the potential of a cam you should open up your intake, increase comrpession a little, and open up the exhaust. You might want to also make sure your carbs are big enough to put out enough fuel at high rpms or for a 280ZX modify your AFM to put out 3-9% more fuel to richen things up. They all work together. With just a 1st stage cam on a stock engine I'm guessing you'll get 8-12 RWHP which is more than any other single mod will do for your engine. It should also improve midrange torque. But more like 25+ hp if you do all the other modifications together and get it done right.
I have yet to see a well built fuel injected engine run on a dyno... anyone else? (I'm not talking about Datsun race cars)
Last edited by Bleach; Apr 30, 2003 at 03:12 PM.
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