Most of you know my setup and it is in my signature. After converting to the FI this winter, best thing I have done since the 5 speed swap. The long duration cam is not very friendly with the computer and o2 sensors. At cruise 2000 to 2200 where the cam is not very good there is so much overlap the computer has a tough time and it hunts around therefore not running to smooth. We have figured a way to over ride this and it is performing great now. The car is still soggy in the lower rpms. It has a large solid flat tappet in it now. Looking for a roller with less duration to pick up mid range torque and better cruise manners and not lose any of the upper power. The short block is fine and will take plenty of rpm but is it really needed on the street. Do I go with a hyd roller of around 235 to 240s @ .050 dur and keep rpms below 6500 or go to a solid roller of about the same duration and not worry about the rpms. I am running a set of older AFR 190 heads and I think they run out of air above 6500 rpm for the 385 ci motor. New heads are not in the budget right now. If anything I'll have these worked over slightly.
valve lift Intake cfm Exhaust cfm
200 126 102
300 198 150
400 243 175
500 268 190
600 262 194

Compression is at 10.7 to 1.

 

Unless you buy the rev kit from AFR or someone else the rpm's will probably stay below 6500 due to valve float from the hydraulic lifters. You have to make compromises on camshafts, what do you need to do with the car? You can accomplish a lot from torquey low rpm cams on the street, but if its track work you will need higher rpm's. I wanted my car to be all things to all people but realized that is not possible, so I'll settle for torque and low rpm's and a street environment. If you want more power you may have to go big block.

 

Yea I hear ya on what the car is for. Not going to be a track car. Certainly not a DD either. Just a weekend fun toy. Here is a solid roller that I was looking at.
http://www.compcams.com/Cam_Specs/Ca...?csid=305&sb=2

Something in this ball park as far as lift and duration I think should work. Just don't know on solid or hyd rollers. It is only driven 1000 to 1500 miles a year and not worried about adjustment as I ahve run solid flat tappets for years.

 

Since it isnt a full race car I would go with the hydraulic roller. For multiple reasons, best one being you don't have to lash it every weekend. Secondly with a solid roller if you keep it sitting for a while without backing the rockers off it weakens your springs. Third, you would have to shell out for new springs, retainers, locators, etc...Finally being how often you intend on being above 6500 rpm's? My guess is probably not too much.
Yeah you will get about 12 extra horses from the solid rollers due to the ramp rate advantage they have over the hydraulic, but since you aren't going to be racing it competitively, then I would just go with the convenience of the hydraulic roller.

 

I can actually run the same springs I have on my solid flat tappet with most of the hyd rollers that I have looked at. That would save some $$$.

 

valve lift Intake cfm Exhaust cfm
200 126 102
300 198 150
400 243 175
500 268 190
600 262 194

Compression is at 10.7 to 1.

With those numbers and my experience with 3 different solid roller cams on my 383. I was worried about over camming on my first build. So I installed the Crane cams street solid roller 232/240 with 1.6 RR's it had 112 lsa Flat top -5 cc flat tops 64 cc heads .041 quench.

It was on the edge of detonation with pump max unleaded. Even at the recommended 32-34 degree mech advance with 6-8 degrees of vacuum advance. I always carried morroso 104 octane booster. Racing I mixed 20 ish % of 150 octane methanol. It had good power and mild lope. It was not a race car sound. I took 3000 mile round trips. When it blew a head gasket I think I had moved up to 1.65 I RR's

Next cam was a custom billet Crane 240/248 again .600+ lift with 112 . With a racing 700R4 it was way to high strung with the same Dart 221 cc heads. I tried the AFR 210cc race ready's on it and it ran the same 820 cfm double pumper and Wieand single plane & demon carb.

It might have been great with a 5 speed. I then jumped down to Comp Cams 236/242 112 custom billet with extreme ramps and big buck springs. Where it is today. What a joy to drive with a 5 speed. Each time I installed it when my 427 had problems it was almost a shame to put it back in the box.

 

My build is a 383, 10.4 to 1, with a comp 236 / 242 HR cam 114 LSA,(nitrous) .520 / .540 lift, AFR rev kit. If your quench and cooling systems are good this cam with a 112 LSA will probably work. That would be Gkull's cam in a HR version. A wider LSA like mine will be a safety cushion for detonation and give you a little better idle quality, vacuum and a wider working RPM. You will give up a little peak HP with the wider LSA but cam selection is a compromise. I think most of the fuel injection grinds are a 113 or 114 LSA for the reasons you mentioned. No sense in going with bigger lift as your heads will not support it. Looking forward to recieving the Dragvette setup, Thanks!

 

Yes it will. It will feed an 800 HP BB. 1000 cfm throttle body.

I ran the dyno with a Victir Jr and an 825 Mighty Demon.


I was looking at the wider lobe seperation for the FI. Not to worried about idle quailty but that would be a bonus. Looking for good mid range power to upper rpm with decent cruise. I know this is asking a lot and George has informed me before on his cams and I think I am leaning towards that. Like I said before solid or hyd does not really matter, the adjustment is no problem. Just need to know if I really need the solids or not.

 

There's certainly nothing wrong with those flow numbers for a hot 350, but I agree they're on the low side as a foundation for a really hot 385. My suggestion would be to maximize the flow potential of those heads and get the RPM in the right range with a cam change.

A roller is perfect for low- and mid-range torque as well as driveability. Do you really need to turn 6500 RPM? With the right cam, your power peak should be a bit lower and you wouldn't need to significantly upgrade your valvetrain. Hydraulic rollers are good up to right around that number; there have been some great tests in CarCraft comparing hydraulic and solid roller lifters that found no difference until we get above about 6k.

I would think something like the CompCams XR270HR would be well-matched to the heads and meet your goals. This is a fairly generic observation, but I'd be happy to look deeper.

 

At 1000-1500 miles per year....I think solid roller is the way to go.

First....you know it..but there is no need to set valves that often just because it's a solid roller. If valvetrain is right you can go a LOOOONNNG time between adjustments.

No need to worry about valvesprings. My 540 is at about 6-7 years on the same set of K-Motions....and they are STOUT. I don't back them off over the winter. Turns 7500 RPM through the lights everytime I run it and it's taken 2000+ mile road trips with them.

You can turn some decent RPM with the right Hyd roller...but it's a package deal. It's real easy for one component of the combo to screw it up.

You won't be getting above 6500 RPM all the time....but to me...you don't usually get above 5000 rpm on the street either. When I DO stuff my foot in it.......I want all the power and RPM I can get. That's what I built it for!

The best manners on the street will come with the solid roller. Just need to pick the right one.

I just built a 555" motor for an upcoming Corvette Enthusiast series of articles. We tested a SR, a SF and a HR. The solid flat tappet was a good one and made more power than any of us expected. The HR made a little more down low, the Solid flat made a little more up top...but it would rev to the moon and when we added big intake and carb it really made killer power. At the end of the day, the SR was up about 30 or so HP over the SF. And the SR had .100" more lift!


JIM


JIM

 

Gordan,

I've been wrestling with this too for some time, and for me the budget won't allow roller anything.

In my research I stumbled on a Motown 415 build that used a Crane flat tappet 244/252@.050 hydraulic ground on a 106 LC. Torque showed 400 lbs right at 2000, and peaked 482 horse around 5800 if I remember. This was with a dual plane intake and 9.5 :1 cr.

I have my eye on a Lunati 401B1 solid, 247/255@.050 also on a 106 LC in an attempt to fatten up the low end, yet keep the top close to what I now have. I also run it as a toy, not a daily driver by any stretch of the imagination. Everytime I fire it up in a parking lot though,...it turns heads with that lumpy idle. Wouldn't trade that for anything,....Unless I could keep the idle, and boost torque. (Hint :106 LC )

 

With the FI the 106 would be trouble. I'm leaning more towards the 112 to 114 LC to keep the O2 sensors happy. The long duration also plays havoc with the FI at cruise rpm 2000 to 2200 rpm. That is why I'm thinking about the roller cams. It would lessen the .050 duration numbers and run more LC without losing the power and maybe gaining some mid range. I'm liking Gkulls cam more and more.

 

You just need to widen your lobe seperation angle to make the motor happy at the lower RPMs. I would call Bullet Cams and see what they can do for you in their Ultradyne lobe library. Go with a R34 intake, R35exhaust with 112 lobe seperation and it should run well to over 7000RPM. Don't put a "juice cam" into a LT-1 Vette! You will regret it! Talk with Bullet link: http://www.bulletcams.com/index.shtml

 

Ok If thats the case I would have to agree with what 427 hot rod has said if you don't put high milage fiqures on you street car even a milder solid roller will out perform a hydraulic roller take a very long time before you need to replace anything.

If you buy a fairly big duration wise cam regardless of whether its a hydraulic roller or a solid roller (you will need to anyway with your compression ratio) both cams down low might be a little less then what you would like but with the hydraulic you have now limited your upper pulling range the solid roller is just going to keep pulling and its going to make more power all the way through the pulling range.

The biggest BS is you have to fiddle around adjusting valves all the time with a solid anything.

I would pick out a wide LSA solid street roller with a tight lash around .016 I would not run one without a rev kit, with lash up top when the lifter comes around on the base circle its unloaded without a rev kit, with a rev kit there is a small amount of load kept on the lifter when it starts to lift the valve no extra slack being taken up, there are other benefits lifter can't go anywhere
if you break a pushrod lifter still held down in the bore.

Then theres the very inexpensive nothing complicated solid flat tappit.

 

Adjusting the valves is not a big deal. I have had solids for years and adjust them once a year. Most of the time they check out perfect. They rarely will need adjusting for the miles I drive.

The solid flat tappet is what I have now. Looking to go down some in duration. This will take some of the power if I stick with a flat tappet. Hoping to not lose much with the solid roller.

The wider Lobe seperation is a must with the fuel injection. It will take away some of the idle loop but that does not bother me.

 

Gordon, as you know, I plan to do the hydraulic roller conversion whenever I can get a deal on some conversion lifters. I plan to run the Chevy LT4 Hot Cam, which is actually milder than the summit 1105 hydraulic flat tappet I'm running now. I may lose a little at 6500 rpm, but I'm rarely there. I don't race anymore, but I am addicted to torque now. Torque is king of the street.
Bee Jay

 

I just got back from a ride in mine. I still like the rpm that the motor can make. Sounds like I'm leaning towards a solid roller. Less duration more lift and a little wider lobe seperation.

I can't go to mild on the duration, I'll run into problems running pump gas.

 

Gordonm,the solid roller is the best performance cam but i had an adjustment problem,it wasnt lomg i had to readjust the rockers ,it got to be a pain after a while,i will not run another solid cam,i want maintance free ,and went with hydraulic roller and it doesnt run as good as the solid roller but still runs great and dont have to worry about adjusting rockers.Bill

 

Not to pile on, but aren't 16 solid lifters kinda noisy? But I guess it's like exhaust noise, the louder, the more serious the engine is. I like French Vanilla, everyone else likes different flavors, but we all love Ice Cream. I love Gordon's car with solid or hydraulic cam. Big inches, high reving, bumper car convertible. I used to dream about that before I saw Raquel Welch in Mother, Jugs, and Speed. Then my priorities got adjusted.
Bee Jay

 

Friends don't let friends put hydraulic cams in LT-1 Vettes! Call Bullet cams and tell them what you have going on they can HELP!