cam change what to expect

I know the dynos don't work that low. The OP is doing a little different kind of racing then normal and some of the tricks from the Fast series may help him was part of my point. The main point was,with a small cam like he has (220 -230 range) any of the shelf grinds and likely a lot of custom grinds are not going to make much difference on his E/T, and no cam change alone is likely to gain him the 1/2 second he was after like Randy pointed out.



One more time now. Show me dyno numbers on all shelf cams in the 268 to 274 advertised duration so we can see the big horsepower difference between them, and at what RPM, especially at the low end of the scale, and how the Custom Cams in the same duration area out perform them.

well I have been turning wrenches all day. so iffen it fires up tommory we will know, lol. bob

You guys can believe whatever you want.

I have personally built & dyno'd a few successful FAST "Factory Stock" and "Modified" class engines. EVERY one NEEDED a custom camshaft to get the torque curve exactly where it had to be. Some required testing 3 or more custom cams to get it exactly right.

To much torque down low and all they do is spin the tires anyway; to little and it won't accelerate off the line ... it NEEDS to be just right for the car it is to be used in.

I don't know about the other guy's. I was referring to the hobbyist street strip/racer with very mild builds. Stock Super Stock FAST Series is a whole different deal. You might as well stay home without a custom cam if you want to be the least bit competitive. I also hinted it would be better to set his car up to his cam choice in other ways to make the most of it, and wanted some very low end dyno numbers and graphs to see what was going on down there to compare and for other cam shoppers to look at.

okay here is the results> two mph and one full tenth in the 1/8. car has much more torque. wheel spins all the way through second now. engine temps are down at least ten degrees. I am sure there is some tech explanation for it all but I don't really care, I like it. bob

Good deal. I hope you get to make a 1/4 mile pass soon. On the engine if outdoor ambient is the same, it may have to do with exhaust heat escaping do to valve timing letting it breath better on the exhaust side not trapping the heat. Did you change the timing from the old cam setting? May be able to bump it higher and get more HP with lower combustion temps if that is the case?

Not saying more timing will help your E/T as it might hurt traction also if you make more power down low, by doing it. Retarding it could even help, all depends.

zbob wrote:gentlemen, tired of high 12s want low 12s.
..... edelbrock rpm heads 75 cc, torker ii intake, proform 850 street carb, shorty headers, 327 gears with 26 tall tires.  two ton pistons 5 in the hole,
.....cam is a wuss cam 213 219 520 lift. gonna try a 274 voodoo cam. I believe it is 227 230 and 560ish lift. I  need enough vacuum for power brakes. ability to drive around minn wisc etc is important to me. will the cam change get it done? thanks bobn

Do you have any 3.0 gears? For what you are doing and since you are spraying, it may be worth a shot. My small block did very well with 3.08's and pulled very hard on the gas up top. I know it sound backwards. You did not give the RPM through the traps. In the quarter it should help even more, depending on you RPM at the stripe. The normal race car rules of thumb go out the window on this type of racing. It's kind of like the lower levels of the FAST SERIES.

zbob wrote:okay here is the results> two mph and one full tenth in the 1/8. car has much more torque. wheel spins all the way through second now. engine temps are down at least ten degrees. I am sure there is some  tech explanation for it all but I don't really care, I like it. bob

Sounds like "high 12's to low 12's" to me ...??? Your expectations seem to have changed a little.

yes randy reality set in. what I came to appreciate is this is still a fully streetable, power brake equipped, muffled, idling, decent engine temped car I can use and drive ......bob

super, yes still have the 327 gears. gear changes and a plate kit is a winter time goal. its fall in northern Minnesota. time for outside get ready for winter chores. fwiw should have got a small cell a long time a go.....bob

zbob wrote:yes randy reality set in. what I came to appreciate is this is still a fully streetable, power brake equipped, muffled, idling, decent engine temped car I can use and drive ......bob

super, yes still have the 327 gears. gear changes and a plate kit is a winter time goal. its fall in northern Minnesota. time for outside get ready for winter chores. fwiw should have got a small cell a long time a go.....bob

You got an increase of about what I expected for your combination.
Keeping it "fun to drive" is a lot of what this is all about; unless it is an all out race car.

zbob wrote:gentlemen, tired of high 12s want low 12s.
..... edelbrock rpm heads 75 cc, torker ii intake, proform 850 street carb, shorty headers, 327 gears with 26 tall tires.  two ton pistons 5 in the hole,
.....cam is a wuss cam 213 219 520 lift. gonna try a 274 voodoo cam. I believe it is 227 230 and 560ish lift. I  need enough vacuum for power brakes. ability to drive around minn wisc etc is important to me. will the cam change get it done? thanks bobn

If the board want to see it and your willing I will design a custom camshaft based the engine combo and the goals. Here is my only stipulation. You pay for the cam when I send it. Once you test it no matter the results I refund you the money for the camshaft. Offer is on the table.

Straubtech wrote:

supervel45 wrote:I was going to mention, I want to see the dyno pull start as low as possiable, like under 2,000 Rpm so we can compare down low numbers. Almost everyone looks at the peak HP when cam shopping.

Won't happen on the dyno stuff.  Most dyno shops have water brake units.  A water brake dyno below 3500 rpm is not accurate due to the absorber and how it works.  Now Ford has a few that will test them but most engine shops don't drop a few million on just a dyno.

Just about ANY electric dyno like a GE, Westinghouse or Froude will pull a 1,000 lb/ft diesel down easily.

Katech has 3 of 'em and they are within walking distance for me.

That would be fun to do some tests with. I would like to see some of the old single pattern cams run against all this new stuff just to see how they compare. Not a lot of dyno charts on the 460's at least compared to the SBC's. I am not trying to put anyone's cams down, I just would like to compare them with a basic stock engine and heads, with headers, dual plane intake and 750/850 carb. Most of the dyno stuff is more race oriented it seems. ZBobs test is very not subjective as it has too many variables, still waiting on 60ft and 3.30 times with the old one to compare. Also his observations of how he likes the cam change on the street as for as overall performance, compared to the old cam would be nice to.

pm sent. straub....thanks bob

Well Bob, Straub has laid down a challenge.
I know what you've done with a pile of bolts and happy that it's always improving.
We know each other's rides like their our own and I wouldn't pass up Straubs offer if it was me.
I want to see the Zephyr in the 11's!!!!!!!!!!!!!

f250mike wrote:Well Bob, Straub has laid down a challenge.
I know what you've done with a pile of bolts and happy that it's always improving.
We know each other's rides like their our own and I wouldn't pass up Straubs offer if it was me.
I want to see the Zephyr in the 11's!!!!!!!!!!!!!

We have started the ball. Bob is going to call and we get the details worked out.

So no other changes except a cam swap?

I would like an offer like that...............

Over the years I have not sold cams to customers who have called to change cams. If the stick in the car is fairly close to what is optimum and we can get there with a lash adjustment and maybe some cam phasing then I give the guy that info. I won't sell someone something they don't need. Now if the cam is going to make a difference I will give you a % of increase and the customer can decide if the increase is worth the money spent.

Do you have any idea yet what the percentage increase will be that Bob will pickup over the Lunati he has now with a custom grind, and are we talking peak HP or E/T's?

supervel45 wrote:Do you have any idea yet what the percentage increase will be that Bob will pickup over the Lunati he has now with a custom grind, and are we talking peak HP or E/T's?

yes I do, but in the era of "Internet Lore" I would rather stay quiet and let Bob's results do the talking.

and bob is wise enough not to share intelctual information. bob

OK LoL

This should be fun. Good thread.