I don't know what's come over me lately,but I'm obcessed with the design of my next engine. I've been searching the web and have found several high horse 406 buildups,most of which I might add are running a Vic Jr. and either a roller cam or a solid cam.My current setup idles at 650,pulls like King Kong and will tip 6500 in 1st and 2nd gear if I want to play.I'm not sure I want to spend the money on a roller cam,so I'm toying with a larger XE series or a solid flat tappet,but first maybe trying the Vic Jr.(or other single plane intake)

The engine is fresh so there's no hurry on this,just thaught I toss a few ideas around.The manifold is a weekend project that if it doesn't work out I could swap back for little money or time. The cam however will have to wait till I decide to pull the engine for freshening up,and if I put in the wrong cam will be a huge PIA to swap.

So the question goes out to you guys that actually drive grumpy sounding,should be on a trailer but somehow still pass the annual inspection type cars.

1 How long between valve lashing can you drive if you run a solid cam?

2 How much lift and duration can still be driven daily?(I'm at 240/246 duration and .545 lift now and think there's still a bit more I could run.)

3 Am I nuts for even concidering this since the curent engine will flatten your eyeballs when I hit it hard? :crazy:

 

No you're not nuts but I possibly am :lol:
The motor I'm building is going to be on the edge I believe. I am going with the XR286R solid Xtreme Street roller from Comp Cams. It is 248/254 deg duration @.050. and over .600" lift. I am not sure how my accessories will be with this much duration but I can run a vaccum can.

I will have Vic Jr. intake as well as Vic. Jr. heads and will be runnig 11:1 compression. I have already bought the cam and hope it is not too much. I have about 7,000 miles on the soild cam I put in this summer and I am going to check and see if the lifters need adjusting tommorrow, but I don't think they will.

I would think the most you could do is go up one cam and you probably will be doing alot of work and spending money on something that you probably won't even feel in the seat of your pants. You have to jump up 2 or 3 cam sizes to make it worth the bother and that puts you in street unfreindly zone unless you go to soild roller.

You have alot of duration already how much vaccum do you have at idle right now ?

 

There are lots of things you can do to try and tweak the engine. Do you have 1.6 roller rockers? That will add a little to the cam.

Different manifolds, heads, or simply degreeing the cam can make a noticeable difference.

Maybe some dyno time to tweak the engine in addition to any of the above.

 

I've changed a few cams without removing my motor.

I've also changed heads while the motor is still in the car. Both jobs take about the same amount of time. Only the head R&R is easier.

I don't believe that more cam is the answer. The real power maker is just the heads. I use the Dart 227 cc on my 383. Your 406 would even make them work better. Heads are actually cheaper than custom roller cam packages with high quality parts.

Just a ruff price out of my last Solid roller:

custom XR solid roller with carbon fiber dist. gear $400 with shipping
Crane lifters $550
CC +.200 pushrods $140
Cower 1.65 SS rockers $350

I already had the taller 7/16th ARP screw in studs and guide plates and Crane gold stud girdle. Almost forgot You have to buy a roller button timing cover and I used the Billet steel Crane timing chain and gears. That's about anothe $300 with the two piece timing cover.

So over all it's over $2000 dallars for a nice roller setup. Heads with new gasket sets are much cheaper

 

MotorHead,
I don't have a vacuum gauge anymore(if you can believe that),but the idle is around 650 in gear.I've noticed lately with the cool mornings that sometimes the power brakes have no power.This is rare,but happens.After a short period the booster kicks in and all is well.I didn't notice this during the summer after I finished recurving the distributer.During that time I had tried initial timing settings all over the place,and if the timing was down around 8 degrees I'd get the power brake problem,and an idle that would rattle your molars loose.And BTW,you're going to need a new radiator.

My gut feeling is that I am on the edge for the cam,but that's why I'm asking you guys for your opinions.George,your price list is exactly why in my opinion the roller setup is out. I can't get the budget passed in Congress for that one.(The wife.)From what I've seen,a strong hydraulic or solid cam can come so close to a roller it isn't worth the expence.Of course the roller will idle much better,but in my commute,the idle lasts only long enough to pull out of my driveway,then it's 40 miles till I pull into the office parking lot,with nothing but country backroads and secondary highway in between.Idle isn't a concern of mine.

I stumbled onto a write up on a 383 that pulled 560 hp running a Comp 306S solid cam and a Vic Jr,but as usual the dyno chart starts at 3000,so you don't get a feel for how the idle would be. I suspect it would be nasty.That cam is 20 degrees bigger than mine on paper,but from what I read a solid needs to be around 8 degrees larger than a similar hydraulic to make up for the losses of lift and duration caused by the valve lash. That means to me that a 250 degree hydraulic would produce the same lift and duration as a 260 degree solid.Could be wrong here,but why mess with valve lash adjustments if a hydraulic will do the same trick?Also a 10 degree gain in duration is worth a 500 rpm shift in the torque curve,so that shouldn't be that big of a deal in my case.Again I'm not sure,that's why I'm asking.

I got a head ache.................think I grab a beer. :banghead:


[Modified by The Money Pit, 1:23 PM 11/1/2003]

 

Money Pit:
Are you ever gonna actually 'RACE' this car at the strip, where a 'combination' of parts is critical, or are you just trying to stuff the biggest 'stick' in there, for the sheer 'WOW'-factor?
My '79 Z28 has a 10.3:1 355", Victor Jr., 750 dbl-pump, DART (iron) head, 292H cam, THM400 with low-gears, 8"/4000-stall converter, etc.
It makes approx 400-420 (?) HP, and runs mid/high 12s @ 106 in a 3800+ pound car with slicks and a 12-bolt/spool rear end.
I'd think putting even this 'mild' motor in my '82, with the 255/60R15s, would NEVER 'hook', and if it DID, it'd probably spit-out the rear-end gears & axles.
You can only 'go' so-far; I'm guessing you're damned-close now.....

 

YOu might want to think about getting your heads fullly race ported if they aren't already. I don't know what your heads flow but I was told you need to be at least in the 270 - 280cfm @ .600" range for a healthy 406ci. :D

My radiator was upgraded to four core, is that not enough ?


[Modified by MotorHead, 2:28 PM 11/1/2003]

 

Glensgages,
I am an addict.Been building engines for 25 years and every one has been bigger and stronger than the one it replaced. I have no intention of racing,as I can't afford the inevidable catastrophy at the track,but after a hard day at work there's nothing more pleasurable than pulling out onto the highway to the tune of 6500 rpms barking the tires at every shift and watching the speedometer accelerate like some kids drag race video game.I like to tweak what I've built to see if I can make it better,and I've been successful so far.
But I've now reached the brink of gone too far,uncharted waters if you understand,and need the input from someone that has been there and done that.I refuse to build a trailer queen that can't be enjoyed daily,so all mods I've done have been minor changes,and test driven for extended periods to validate weather they worked for me or not.
Besides that it's a hobby of mine I happen to like.

MotorHead,
When I broke the cam in on my 406 the first time,I ran a stock new 3 core radiator and boiled over three times during the cam break in. I then set the timing at 10 degrees and drove the car to work the following Monday. I was fine for about 25 minutes,but could not maintain the temps any longer.Once I put in the Griffen radiator,the temps never go over 190,even on 95 degree days after running hard.Think about it. The stock engine only put out 190 hp,and now I tickle 500 hp. There's quite a bit more cooling that needs to be done when you get the horsepower up.

The flow numbers on my heads are 262 at .500 lift,which isn't race car level,but certainly above average for a street engine.My thinking is that since the heads top out at .500 lift,I'd try to increase my duration a bit and switch to a single plane to build some more top end power,hopefully without killing the low speed driveability.I realize there's a limit,just don't know what it is yet.

I know one thing for sure.Before I shuck out $2000. for a roller setup,I'll cut a hole in the hood and stick a 6-71 on it. :yesnod:

 

Here's the specs on my new cam: The part number is 12-000-9 which is the mechanical roller blank and the grind numbers are CS 4875S/4876S SR112+4. The lobe separation angle is 112 degrees. This cam has 4 degrees ground into it to improve the lower rpm torque so when it's installed at 108 degrees it will essentially be straight up at 112 degrees. The lift is intake .616"/ exhaust .622" with 1.6 rocker arm ratio. Duration @ .050 is Int. 248 & Exh. 254 . The cam timing events @ .050 are 16 52 63 11.

My engine is only going to be a 388, so it would be a bit tamer in your 406, but I don't know if it would be much ;) . I think this cam is on the ragged edge of being "streetable" . I will be lucky if it idles under 1000rpms, it will probably be more like 1200-1400. I can't wait to get this engine installed. It will be all means sound like a "racecar" :D .

Gkull has the most experience of driving a solid roller cam, & from talking with him he doesn't have to adjust the lash very often (2-3 times a year) from a guy that puts many miles on his car each year ;) .

**Edit** A few things that are in my favor to run a cam this big is that I will be EFI and I have a manual transmission. I don't know if I'd go with this much duration if it were an automatic ;) .


[Modified by SmokedTires, 6:39 PM 11/1/2003]