blctalon

I haven't been on here in a while and haven't been messing with my vette much. Come to find out, my cam is wiped. Found a valve barely opening when I was adjust lifters with the engine running. Ended up tearing off the intake and found a concaved lifter. Tore the engine apart and found some bits of metal in my main bearings and a pretty round cam lobe. I'm pretty sad because the engine had less than 2000 miles on it. It was sitting a while because I lost interest in redoing the intertior

Anyways, I'd like advice from the experienced engine builders on this forum as I know there are some. My engine is a 406, bore is 4.155, rods are 5.7, pistons are .005 in the hole, crushed gasket thickness is .039", gasket bore is 4.2", mighty demon carb, edelbrock rpm intake, afr 180 competition package heads. I know many will wonder why 180 heads on a 406 and the reason is because at the time of the build I was following a chevy hi performance article with these parts that made 490hp/527tq so I pulled the trigger to make my package the same. This was 7 years ago.

Using the above info I'm at 9.44:1 staic and 8:1 dynamic (using kb calc, 8.6 using the wallace racing) with the cam that went flat which was a lunati bracket master II 230/230 @.050 .515/.515 WITH 1.6 rockers. Engine had a nice lopey idle and pulled hard to 6200rpm where my limited was set.

I don't have a problem putting a similar cam in since it ran good how it was, but I'm going to retrofit roller this time and would like to squeak as much out of it as I can with my current parts. I guess my question is how big is too big with my static compression? Thanks and happy new year in advance!

Billysvette

Please do yourself a favor and put in a hydraulic roller cam in it and you wont have to worry about wiping cam anymore.There is no down side to doing this except it cost little more money , please do this.

blctalon

I absolutely plan on the roller this time around. 7 years ago the retrofit stuff was more expensive than now so it's doable this go around.

Looking more for advice on cam specs to run with my combo.

Thanks!

larrywalk

Here's a really nice roller:
http://www.lunatipower.com/Product.aspx?id=1992&gid=290
(Make sure to know how much cam lobe to connecting rod bolt clearance you have - a small base circle cam may be needed.)

Had a very similar duration solid roller in a 406 with 9.6 CR - loved it!

MotorHead

I have always liked the 286HR Magnum 230/230 @ .050" but the lift is way up there in the ~.560" range if I recall correctly. If I didn't like solid rollers I would have tried this cam at one time or another. I talked to someone who had it in his engine and he said it was a great cam.

I don't want to tell you to get it because I have no personal experience with it but it has lift higher than some solid rollers with only 230 duration meaning you can run a lower compression ratio. If it works the way I was told the power gain would be huge

garygnu

try cam quest 6 at comp cams ,and try several different hydraulic roller cams.make sure all your oil passages are cleaned out.

63mako

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

blctalon

Thanks for all the suggestions. I played around with desktop dyno and camquest 6. The larger cams (around 240+ duration) seem to like the heads flow rates but according to a tech at howard cams he thinks those will be too big for an automatic transmission and 3.55 gear. He recommended a 232/241 @.050 on a 112 LSA. Said the wider LSA would tame the idle a little and the overall size of the cam would work better with an overdrive transmission. Said there would be less surging in overdrive. Oddly enough, I did have some slight surging only when I let off the pedal and coasted. He seemed to know this without me telling him just based on the previous cam spec I gave him. Does this sound about right? I'm assuming Howard's Cams are good quality? Seem like a deal for roller lifters and a cam.

Cam quest recommended some nice cams but I think I was in the more aggressive range of stuff just looking at peak power numbers. It's not a daily driver so I don't mind if it runs a little rough but if going a little bigger on cams will make it surge and act naughtier I guess its best to be a little conservative.

Little Mouse

[QUOTE=blctalon;1582715538]Thanks for all the suggestions. I played around with desktop dyno and camquest 6. The larger cams (around 240+ duration) seem to like the heads flow rates but according to a tech at howard cams he thinks those will be too big for an automatic transmission and 3.55 gear. He recommended a 232/241 @.050 on a 112 LSA. Said the wider LSA would tame the idle a little and the overall size of the cam would work better with an overdrive transmission. Said there would be less surging in overdrive. Oddly enough, I did have some slight surging only when I let off the pedal and coasted. He seemed to know this without me telling him just based on the previous cam spec I gave him. Does this sound about right? I'm assuming Howard's Cams are good quality? Seem like a deal for roller lifters and a cam.

Cam quest recommended some nice cams but I think I was in the more aggressive range of stuff just looking at peak power numbers. It's not a daily driver so I don't mind if it runs a little rough but if going a little bigger on cams will make it surge and act naughtier


" I guess its best to be a little conservative. "

If you drive anything much at all this is generally a good answer.

63mako

I like the 112 LSA for the reason mentioned by the tech. I can't find a cam with the specs he listed on Summit. What are the lift numbers? Your AFR heads flow real well with good I/E ratios so the big split is not needed between the intake and exhaust. Those heads will like as much lift as you can get also.
The Comp Magnum 286HR is worth looking at. They will grind in on a 112 LSA also but 110 will be fine with the lower duration @ .050. Big lift, no split in duration, 230 duration @ .050 will work real good with your auto. You can order it with a billet core and pressed on dist gear. Run it on the desktop dyno.
http://www.compcams.com/Company/CC/c...?csid=152&sb=2
Howards is great quality, Made in USA and reasonably priced. Downside is fewer choices and options.

Edit: Motorhead already suggested it. Good call.

blctalon

The cam Howard's recommended is http://www.summitracing.com/parts/hrs-cl110265-12 --- It's real close to the one you calleld out. I was told the one in the link is a real popular grind and if summit didn't have one in stock they could ship it in a day cause he had 26 on the shelf. I'll compare the Howard and 286HR on DD to see where they fall. 230/230 is what I had before with the now flat Lunati but didn't have quite the lift as the comp. Was honestly hoping for something a little bigger. When the tires boil to 3rd gear its hard to imagine losing low end with a little bigger cam but I think my setback is auto and over drive.

Oh, i think the reason my cam went flat is because the heads were shipped with
140# @1.930
365# @1.380

When I ordered them from the folks I ordered them from, I told them what I was using so I have no idea why the incorrect springs were installed. Sure wished I would of thought to verify the correct springs back then.

63mako

That is the same exact cam I recommended ground on a 112 LSA instead of a 110. It is a good choice and if I would have seen it on a 112 I would have recommended it instead. I like the wider LSA with auto. The Comp magnum 286 is the same duration @ .050 as your last cam ground on a 110 instead of a 109 so it will be very similar in manners. If you want a little bigger the one recommended by Howards is a good choice. With your 1.6 rockers the heads will like the lift. The springs you have sound like a hydraulic roller spring rate and were likely to strong for the flat tappet combined with the 1.6 rockers but might work well with your new cam. Check the springs for max lift. Might have to change them out.

MotorHead

Many things to consider when selecting a cam. 1.6 rockers could change the recommended springs and they have to be set up right. Is it a billet cam, does it have a pressed on iron gear etc etc?

It is not easy and only the most experienced machinists / engine builders can get it right on the money with high performance small block engines when you get into the .600" lift range. With Comp Cams you can change anything on the cam for a little bit more money. I would not go with anything less than a billet steel cam with pressed on iron gear.

blctalon

All good points. Based on the numbers desktop dyno is giving me, I think I will go with the howard's cam the tech recommended, which is the 233/241. With 1.6 rockers it puts the flow up pretty good. I compared this cam with one a little larger they offer, 237/237 .582/.582 (with 1.6's) and while it peaked more HP it's a little out of my range of operation so it seems senseless to use this cam. It also gives up 7+ or so hp/tq through out my useable power band. Lastly I ran the magnum hr286. It looked good but the 2 howards seem to work best with my combination. The late intake closing of the magnum puts my effective running compression to low, based on "sweet spot" dcr numbers.

The tech I spoke to at Howard's said they use steel out of Michigan, where all the others get their steel and it's USA. I told him I was unaware everyone got all of their steel from the same place, but then he rephrased "some others use imports, but we don't." It would seem they're good quality and best bang for buck since they come with roller lifters in a kit for a little over $500.

edit- should say I will go this route if the cam is billet and correct gear. Pending on their response and how much different it will be I could pick a different one!

howards 233/241


howards 237/237


comp286hr