bluedawg

If your going roller you should go like 220 duration on the intake.

jb78L-82

I used aluminum AFR 180 65 CC heads on my build and .015 felpro gasket
with 9:1 JE pistons. Builder specifically told me to go with a thin head gasket (felpro) and I did with Permatex aviation gasket sealer on both sides of the gasket before torquing it down-block not decked. I decided on a roller cam specifically since I was scared off by the flat tappet cam failures that you read about at startup and even with miles. I went with the Howards Roller ..525/.525, Duration 219/225, LSA 110-engine should make big torque from 2,000-5,000 RPM. Operating range according to Howards is 1,500-5,600 RPM-pretty much the same range as the L-82 cam (.450/.460, 222 duration, LSA 114). Have not fired it yet but very close now that the engine is in. Let's hope for the best.

augiedoggy

I actually looked at that cam. I think it did well in the dyno software I used.

As far as the flattened lobes There are just too my variables... Some don't believe in high zinc oils for break in like these cams originally had from the factory for break in and some don't use the correct springs. Some don't use the correct break in procedure....some don't prime the lifters or The oil system prior to starting or leave the engine sit for long periods after building prior to use any of these lower the tolerances against a wiped lobe and make it very possible....I'm willing to bet something was off to cause both those cams to wipe lobes in a row...( both comp and lunati have about the same track record online the way. Other builder use them all the time and swear by them? I think They have been out for years and if they were really that unpredictable they wouldn't be in business as they would have been sued so many times for destroying engines by reputable shops.
Rollers are more fool proof.... They are more modern and work better for sure just like ls swaps and fuel injection... If I had the budget...

bluedawg

I can't say I've every wiped a lobe, don't have as much experience as some, My brother on the other hand has wiped a couple cams. Aside from him and some forum post that I've read hear, I couldn't name any one else thats wipped a lobe. I guess theirs always a chance and the likelyhood increases with a botched break in. I will say it was nice on the 400'' when I didn't have to worry about it with the roller cam and all.

augiedoggy

I think some guys get overconfident with not having to follow all the precautions on the old school conservative grinds and having things come out OK so when they try a newer style lobe design cam they try to sneak by with "close guess" springs or regular oil for break in... Plus its convenient to blame failure on something like this... I'm sure failure is still possible if the precautions are all taken but I bet its a hell of a lot less likely than some make it out to be.
A roller would have brought my engine build up from 1100 bucks to about 1500-1600... I still had exhaust, cooling mods, the interior and bodywork to do so wasn't gonna happen.

qwank

So I've broken in cams before with no issues, BUT I've never heard of this valve spring thing. I've always put the recommended springs on and broke the cams in with them.

are you guys saying it's safer to throw the stock springs on for cam break in, then put the recommend springs on after?

qwank

since I'm a fan of using GM parts and I get a healthy discount on them at work, how do you guys think the 350HO cam would do with the ZZ4 heads? I know it makes 330hp/385 torque with vortec heads and similar compression.

http://www.summitracing.com/parts/nal-24502476

jb78L-82

Thats a fairly mild cam and similar to the L-82 cam with less lift on intake and same lift on exhaust as the L-82 cam. Duration is slightly less on intake and same on exhaust as the L-82-222 duration-Should make decent torque. Just keep in mind that the 330 HP/385 torque is GROSS and will be substantially less for Net HP like today's cars are rated (about 15% less) and 15%-18% less for RWHP, depending on tranny and driveshaft loses. Probably about 275-280 NET HP in today's world.

scottyp99

Here is a cam with very similar specs, plus new lifters, for a little less money.

http://www.summitracing.com/parts/su...make/chevrolet

Scott

glen242

10,000 motors??? Average work year is 200 days. 10,000 divided by 200 = 50 years, and that is saying that he built a motor/day for 50 years. How old is he??

I understand EVERYTHING is bigger and better in Texas , but building that many motors, unless on a factory type assembly line, does not ring true!

I am sorry to question this 10,000 number you posted, but it does not ring true.

marz

He is an old coot. That's what he claims and I have no reason to question him. When he was building mine he was working on 8 other motors. And he still races on weekends. I would bet he could put one together in his sleep.

qwank

Scott
did you see my original post i quoted? I guess I'm back to square one.

check out this article:

http://www.carcraft.com/projectbuild...ckage_install/

they dynoed the 350HO and then swapped in an XE262 and got such a small gain they didnt even print what it was, then they swapped in an XE268 and only gained 7 hp over the 350HO cam.

qwank

I think the stock zz4 springs are going to be too much for any of these cams we're talking about.

here's the specs:

http://www.summitracing.com/parts/nal-12551483 it's a 332# spring

I'm thinking I should use the 350HO springs at 256# or similar

augiedoggy

I wonder if he could manage to put one together in his sleep that won't wipe the cam out? :P

augiedoggy

That only means that its likely that other components like heads, compression or exhaust were likely limiting the cams potential.... some parts just complement each other and work better together than others..... you want a cam that will enhance the flow characteristics of the heads not work against them.. and without increasing air and fuel flow completely through the whole engine from air cleaner to tailpipe you still are limited a great deal by the weakest component.... like those who buy high flowing heads and then bolt the stock manifolds back on... you won't see anywhere near Max potential out of those heads or the engine.

qwank

well they used vortec heads, long tube headers and a performer rpm intake.

I'm using zz4 heads which don't flow as well unless I have them ported, and I want to use my stock aluminum intake so I can use the stock air cleaner setup.

the ZZ4 uses a cam with HUGE lift to make 350hp 405 torque, but I'll never get a cam like that unless I go roller.

I'm still thinking the 1103/350HO or Voodoo 262 is going to be my best bets for a flat tappet cam in this engine.

what about 1.6 rockers to get a little more lift? (I know I can;t break the cam in with them)

bluedawg

Depending on the cam profile or how aggressive the lobes are, the more aggressive lobes the harder the cam is on the valve train components, add 1.6 rockers and it multiples the abuse on the valve train. On a less aggressive camshaft they are a great way to increase lift and horse power. I ran them on the xe262h not before and after the dyno, but the did make a seat of the pants difference. On that engine well worth doing.

jb78L-82

Two quotes from forum members about the stock L-82 aluminum intake based on their experience:

"years ago my 79 l-82 Vette had the hot rodded 355 ci with headers, true duals, P&P 186 casting double humps. I took it down to a rear wheel dyno tune place. After dialing it in with a edelbrock 750 and the stock aluminum intake - Which I'm told was the same intake that came on the LT-1's of the 1970 time frame.

I don't have all the dyno sheets anymore, but the stock aluminum intake made significantly more HP the the sorry Edelbrock performer. The Edel. really shut down over 5000 rpm. Where the stock intake continued to make power out over 6000 rpm.

The Edel performer is meant for your old farm truck. Probably marginally better than some stock cast iron setups.

My other manifold that I left on after testing was the Weiand single plane with 1/2 inch wood thermal spacer. It was with a 1-2% on HP and TQ below 4500 rpm compared to the stock aluminum and then went up above out to the 6500 end of tests.

This was with a Crane 272 powmax cam. It seems to me that corrected power was = actually about 380 or so at the crank shaft with the single plane. Weiand Excelerater or some name like that. The L-82 aluminum probably had an equal average power to 5500 or so and the "Performer" just ran out of air so fast that it was a waste of a couple of hours to change it in and out at the dyno shop. It's just a bad product and waste of money."

Another forum member:

"I had the Performer on a 357 (.040" over 350) years ago. It does run out of steam at 5000 RPM. The LT-1 and copies are a better intake for high RPM but no surprize there. If you can fit the Performer RPM, LT-1 or the Holley 300-36 under the hood you should be pleased.

I currently run my 350/350 with a stock L-82 aluminum intake. It does not run out of gas at 5000 RPM but I have Dart (better) heads so that is probably helping a bit. I might be leaving something on the table here with that intake but with the balance of the rest being stock it probably isn't much."

My builder said EXACTLY the same thing about using the the L-82 intake on my AFR's for my engine that will rarely see above 5,500 RPM.

augiedoggy

That's pretty much how they are advertised... The performer is a stock replacement designed to optimize power in the normal driving range as dual plane intakes create torque at lower rpms. The rpm just extends the runner length a big and manages to make power all the way till 5500-6000 rpm but it also starts building power a few hundred rpm higher. The l82 manifold is actually the manifold that edelbrock based one of the performers on
A single plane is great for Max HP and torque and the highest rpm capable by the engine.... the trade off is for a car that going to spend 90% of its time below say 4,000rpm they offer noticeably less toque and HP in the normal lower street rpm range.... this is why real engine guys use them for drag or race cars.... they are NOT a wise choice with 3.08 gears.
The air gap is supposed to be a compromise of both dual plane advantages and the cutout to allow it to have some of the advantage of a single plane. In almost all the applications I read about the cutout significantly hurt lower rpm torque and when the operators swapped in a rpm or clone the engine "woke up" in the range they wanted.
The actual air gap under the Carb is proven to lose its cooling advantage about 10-15 minutes after the car is started so yes there's an advantage for drag racing maybe?

marz

Always a wise guy in the bunch.