Roller vs solid

In an all out stock appearing build what would be the power difference between a solid flat tappet cam and a roller. 499/400 iron intake and exhaust manifolds.

You need more than that to get any decent response

is it for the car in your signature?

Can't really say specically, but since a solid roller can have faster ramps with more area under the curve with less advertised duration the improvement could be substantial. This all depends on air flow of the heads, intake and exhaust though. Along with other factors. If I were you and looking for all you can get out of the combo I would talk to several different cam grinders and get their suggestions before making a decision.

Nice running car you have already, hope you can find what you're looking for. Pics would be nice!!!

As with most things related to this type of discussion........ “it depends”........ on a number of things.

That particular combo the OP is running really suffers from the stock iron intake manifold.

I’ve never done the SFT vs roller cam swap in one of those builds, but once you’ve got one running pretty strong....... finding extra power in that type of build usually doesn’t come too easily.

I know you can’t run one, but as an example....... my suspicion is that a pretty good SFT cam with something like an RPM or 6bbl intake would be noticeably better than the same motor with a killer roller cam and a modified iron manifold.
Just speculation on my part.

Yes. New engine build.

FB_IMG_1574727577096 by cudadude2, on Flickr

Untitled by cudadude2, on Flickr

Sweet!

I can't answer your question but, I've read all your posts on here and FBBO because your car is exactly what I've been moving toward with mine; well, except that I have one year newer technology (69 Road Runner)

Did you get the 11.90 with the 451 or have you already switch to the 499?

What are the specs on your current solid if you don't mind sharing?

Love the car!

Awesome car!

451 with factory 440 rotating assembly. .6ish solid flat tappet cam. 10:1 compression. Ported intake and heads lots of practice.

If it helps, here are the number 1 & 2 times for our combination:

11.52 120.28

11.58 117.98

Both were 511ci. I know for sure the second had a solid roller; pretty sure the first did also but, can't confirm.

So, with your plan to go to 499ci and a solid roller, I'd say you can potentially pick up around .3 once everything is sorted out and you've practiced, tested and practiced some more.

Comp cams probably offers 30 SFT lobes and probably a 100 solid roller designs. Maybe share what you have now? Maybe ask opinions on a certain SFT lobe verses a certain solid roller lobe. The head flow info through 0.700" might be helpful too.


If you're using MM lobes with a 1.7 rocker ratio and comparing it to a High Energy roller w/ 1.5s with similar seat timing, probably no gain, maybe a loss. If you are comparing an High Energy SFT on a 1.5 verses a TK lobe with a 1.7 probably 70 hp.

That sweet Runner already runs good !! Ron

Untitled by cudadude2, on Flickr

Here’s the questions to ask yourself......

How much of a gain in power would you have to see out of the SFT to roller swap to justify the cost.......and does that seem realistic?



The #1 motor made way more power than the #2 motor(it was also a much more expensive and sophisticated build).
It just shows how important the overall set up is, as motors with very similar power to that one have gone well into 10’s in heavier cars.
There was def a fair amount of ET left in that car.

Assuming the same weight, the speed difference shows there to about a 30hp spread between those two motors.
The actual difference on the dyno was more than that.

The #1 car could, and would break the tires loose pretty far down track.

The #2 car was much more predictable and easy to drive.........Once you were out past the 60’ clocks, you were golden.

That’s kind of what I’m trying to determine. I’d prefer to stay solid flat tappet, but if there’s more than a tenth in going roller I’d likely take that step. I expect to get everything out of either package when it’s done just would not want to do it twice.

B

Going strictly by the numbers...... in that 118-120mph area, at around 3500lbs...... if you don’t waste any of it....... a tenth is a little over 1mph...... which is worth about 15hp.

So, that seems like a reasonable expectation to me.

Interestingly....... the motor your cam came out of was swapped to a roller.
That was a 6bbl though, and the heads got updated a little at the same time.
I think the gain was over 3 tenths(or more) with that combo.

Man I hate to see you spend all that money switching over to a roller cam in quest as you say you would be happy with a .10 of a second. I have seen so many people unhappy with this upgrade. You could very well see nothing with a stock cast iron intake and factory exhaust manifolds. There are way easier upgrades that are cheaper too.

roadrunner2, thanks for posting the cam card; I find it interesting, not what I would have thought.

Dwayne, as always, I appreciate your insights too!

Dwayne, I'm not asking you to give away any secrets or go into too much depth, I just know that there is more than 1 way to skin a cat and would like to know, if you were to spec a SFT for roadrunner2's 451, would it look anything similar to the cam card?

Could you share those FAST legal upgrades that would be worth .10?

Sure. Learn to cheat better. I could tell you but then everyone would know.

It would help if those posting would give enough info when starting a post. I didn’t see this was a FAST engine type build till you mentioned it. Must be top secret. Lol.

Well, you’re allowed to do pretty much anything you want that doesn’t show.

It’s straight up heads up racing....... so whatever else you did...... if you left a tenth on the table by not using a different cam....... it’s still there for the taking.
Maybe the guy next to you didn’t leave it on the table.

But...... I agree that when you're asking for advice for things pertaining to running that class, it’s best to mention it right at the start, since there are things that work for other types of builds that don’t work for FAST type builds.

I did say "all out stock appearing build". Car is being built to run in the SuperCar series, but besides that and FAST I'm unaware of what else that could mean.

Bill

Since you are traction limited I'd think the power difference matters less than the shape of the torque curve. And a roller cam would give you more control over the shape of the torque curve since you can get a lot more creative with the lobe shape. So if it was me, I'd start with a roller cam and never even bother using a flat tappet. I'm not saying it is going to be easy to find the best torque curve to match your chassis and your driving style, but with a roller cam it will be a lot easier to make adjustments.

I cannot tell you how much you would gain. Probably not much if you are keeping identical advertised and 0.050" numbers you have with the Scott Brown cam. A roller isn't going to move the valve much faster than that. Is the 0.200" duration above 165°?

Are you in an all out chase for the top spot relative to the "other" cast iron 4bbl intake BBMs in FAST and SC?

If so, I would probably suggest something like this order:
1) Make the intake the very best you can within your skill set/budget.
2) Install and go to the track and test with the cam you have now.
3) Then after establishing a solid baseline corrected to std conditions, then start changing testing and recording the results of the following for the cam you have now:
a) increase and decrease lash 0.004" on the intake.Keep going until it slows down
b) then do the same on the exhaust
c) then advance and retard the cam in 3° increments.
4) Read the tea leaves from the data and extrapolate your findings to spec youself a solid roller from what you've learned picking lobes that move the valve as fast as possible. Your valvetrain will hate you.

If you have not done this already, you might find a tenth or two and a mph or two with the cam you have.

Or call Dwyane and have a conversation.

Roller is the way to go.... Hands down...

Obviously only one way to know for sure....... but......

Based on my assumption of what that cam is, I’d say it’s 165.

Bill can say if this is right or not, but I think he’s running 1.6 rockers too.



Well...... yes..... and no.
But I’m not going to get into any details....... also, as you say, there’s several ways to go about it.
And...... obviously that cam is working pretty well in Bills car.

1.6 is what the card says. Looks like they are 6583/7396 lobes.

From what I understand, the cam was in a different motor originally.
That motor did have 1.6’s........ I don’t know if Bills are or not.

Those are what I assumed the lobes are as well.

Here you go. My buddy spent 800.00 on carted gears and ceramic bearings and picked up .30 in his 11 second car.
http://microblueracing.com/?fbclid=IwAR17jjdtsHqPgR_JlUC2sLe0Z2RDf_9d04F2I5icDDg3B7mk__Zxi5dHDrU

Untitled by cudadude2, on Flickr

Untitled by cudadude2, on Flickr

Untitled by cudadude2, on Flickr


Untitled by cudadude2, on Flickr
This is the intake that I'm currently using on my 451. I have a much improved one that I'm building now with an even better one planned after that if I continue to try to compete with an iron 4 Bbl. That one will require professional help and I prefer to keep my stuff my stuff.

My rockers are HS 1.6's.

Bill

change those rear tires to drag radials or slicks and you will improve even more. LOL.

what are your cylinder heads like???

Not really relevant to the cam question....... but compression is your friend in these classes....... up to a point.

Not legal for my race classes. Have tried them on test and tunes and didn’t see any improvements. Car is designed to work on the little tires.

B

Better than my intake. Medium porting. Big valves.

Thinking 13:1.

B

Your car already has 60’ times better than the two quickest single 4bbl “383’s” in those classes.

With a 13:1 499 under the hood...... if you can keep the 60’ as good as it is currently, you should be able to go after the top spot.

It’s too bad Jim doesn’t bring the Dart out anymore......... there was a bunch of untapped potential with his car.

A little rivalry makes it interesting.

Did you do any back to back testing with the dimpling; if so, what did you find?

I didn’t. I doubt there’s anything in it. But I figured what the hell.

Bill

I recall when the OEM's went roller the commonly quoted number was 15 to 20 hp gain.

Those numbers are feasible for mass production but, for the $800 to $1000 investment to convert, I've always thought more power could be found else where and still be F.A.S.T. legal.

For $1000 and just going off your signature, I'd ditch the 14's and go with 15's to increase your contact patch and you might still have money left over for fiberglass fenders.

15" rims are not legal with a 383 build. Only available with Hemi in 68. Fiberglass is definitely not legal.
I have maybe 100 lbs left that I can pull off the car, and a better ignition system wouldn't hurt, but generally I think I have a good package.

Bill

Are you allowed to use the MSD Grid ignition? If so, you could probably gain some ET by slewing the timing and rpm to help get it going with skinny polyglass tires.

Yes there are a number of cars running a grid. At the moment my setup doesn't have the torque where I can't drive it off the line. My 60's are in the mid 1.7's which is pretty competitive.
It may be something I could look into for the future, but I'm more driver than tuner and like to keep my junk simple. I also want to win tho, so. ?

Bill

Time to stroke that puppy with a 4.25 stroke crankshaft Take timing out on the starting line to improve your 60 ft. times ( with a grid system) and reaction times and then add it back in to make power

I prefer the 4.25 over the 4.15 as well.

While you are at it break out the money bucket and do an LS firing order. I'm still having sticker shock over that one!

If it’s not a commonly available core, it has to be made out of a piece of bar stock as a one-off.

Benefits (other than a lighter wallet)?

Imo, in that combo........without testing it back to back........ I’m not sure it would be worth anything.

For sure........ it would be way way down the list of things I would prioritize money being spent on for that application....... unless I could see decent test data where it was worth enough power to justify the expense.

“The test”........ to see just how bad the intake manifold is hurting the power is to try a Performer RPM against the modded stock piece.
I think it would show you where one might need to concentrate the time and $$$.

Of course, if the difference was only 10-15hp........ then I’d be more willing to spend the resources somewhere else.

On my lowly 383 with stock heads, the RPM was about 25hp over a stock 301 intake.
I’m thinking on a 499/511 with ported heads, the difference could be more.

Tested on consecutive days, two very similar stroker combos running the same ex manifolds....... one with a ported 301, the other with a 6bbl..... the difference was over 60hp.

A little before and after of my current project intake.
Untitled by cudadude2, on Flickr


Untitled by cudadude2, on Flickr

Bill

It will sound like a SB Ford!

(I tested firing orders on my race engine and never saw any difference. My take on the subject is that firing order might matter for NASCAR, F1 and Indy cars. Not sure it matters to anyone else.)

Bill, how were what I assume are flow numbers taken on the orange intake?

I don’t know. Pic from the Internet.

Did you sub-contract this one out or, are you doing to work on this one too?

I'm doing it all myself.

Bill

I thought a big plus was that it made the crank happier?

I've heard that also, I haven't built a motor with that option yet either yet so
I have laid out all the firing orders possible with stock Mopar V8 crankshafts and I couldn't find one that didn't end up having two cylinders side by side firing order more than 90 degrees apart by changing the cam shaft lobes
Ford and Pontiac V8 motors don't use the same crankshaft rod throw arrangements like Mopar and Chevy do

Might be true on a super high output engine but it doesn't seem to make any difference on the typical bracket type engine.

Andy, is your thinking that the firing order swap only makes sense for engines seeing longer duty cycles i.e. road racing, circle track, etc.? I am trying to wrap my mind around the $550 dollars extra in cost for my 511 build. So far the consensus appears to be, using PRH parlance is "a solid maybe" lol

I’ve never done a back to back test.

The cores are available in the Chevy world.
Some customers want it, so I get it for them.
But it’s not like any of those motors that got the FO swap stood out as being anything extraordinary.
They worked as they were expected to...... even without considering the FO swap.

The most abused motors I’m involved with are supercharged marine stuff.
They don’t seem to experience an unusual amount of crank failures....... almost none that we see have a FO swap cam.

Supercharged and marine...that's engine torture!

Thank you for your insight sir.

Well the final numbers are in for my flat tappet 10:1 451” stock appearing engine. It will be retired following a run of 11.63 @ 119.09. Traction wasn’t the best and it 60’d at 1.77 and the DA was over 1200. I am more than happy with what I was able to get from a very mellow build. It nearly matched the numbers of the fastest “383” builds ever.
I’m just a few weeks I’ll be pulling the 451 and replacing it with the 499” 13.7:1 roller cammed build. My original goal was to go 11.4-11.3 at 120 but with all I learned from racing the little engine I may have to revise my expectations.

I’ll keep all posted

Bill

Nice job Bill...... I know you’ve been hard at work on it

I know a guy who did that in a Stock/ Superstock combo car, and didn't see squat on his time slips, that was noticable

I can only tell you what he told me. I didn’t want to call him a lier.

Great job!

Been very interested in your car. I'll be looking forward to seeing what you can do with the new combo.

My builder has a couple of GP Hydroplane engines waiting for him to finish upgrading his dyno for.

It's a wonder they don't break EVERYTHING!

They run WFO at 8200+ for 5 miles plus warm up laps and if the prop comes out of the water which happens regularly, they buzz past 10,000 only to instantly get yanked back to 8000 or less when the prop hooks back in the water.

One team had a Pro Stock builder that thought he was all that do an engine for them. The boat made the fastest 3/4 of a lap ever recorded before it emptied the crankcase into the bilge.

Marine engines have more in common with dump trucks than race cars. Lol

Kevin