roger3

Nothing yet. Chris wasn't sure if he would be able to finish my cam this week or not, he had some orders ahead of mine. If he doesn't get to it this week it will probably be after the hollidays before he gets it done.

Your comments made me think more about dynoing the engine. I plan to dyno it with the shop's headers, electric fuel pump, and no air cleaner and let them adjust the timing and carb for best perfromance.

Then make a couple runs with my air cleaner to see how much it costs in Hp and Tq.

Then add my headers (open, no side pipes) and see if they hurt the engine's perRromance. I didn't know that side pipes are not tuned lengths. Then add my side pipes with baffle inserts and see how much that costs in HP and Tq.

It will be interesting to see the comparisons.

Roger

gkull

If you look up header science on the internet, you will see a relationship to primary pipe diameter and length VS RPM of a given motor CI. Side pipes are not (tuned) because the only thought put into them is how to get the 4 pipes to the outside of the car.

Most all small cam places buy blanks from places like Crane cams. Blanks are complete cams with with lobes and when delivered the individual just grinds down the lobe to his specs. So you might end up with a different ramp rate on the opening and closing or some slightly altered lobe center or lift. but it is nothing magical.

It just take a little bit of thought and looking through the lobe charts from the major companies and you can design your own custom cam. I don't buy anything except dizzy sleaved gear on billet steel cams. You never have a flat lobe or have to worry about Dizzy gear compatibility

Cstraub69

I wish it was that easy.

crf311

Don't forget to change the gear on your distributor.

Cstraub69

You can run a bronze gear on any cam core. I would run a Melonite.

zwede

An H-roller should have a pressed on iron gear which will let you run any factory distributor gear.

gkull

Are you talking about custom cam designing. If you are out there running your car hard, you get to know what the motor is like. So if you know your cam specs it only take a little thought to know which direction you want to go on on lift and duration. I've guessed to big before and had to buy a milder one which was just about perfect for what I was doing.

I also get to build and drive a variety of hot rods. So it has been a many year learning curve. I prefer a wide power band over something that sounds like a drag car that is not functional for 95% of street driving.

I prefer roller cams

Cstraub69

There are several cores that can be used that dont require a pressed on gear. The USA made SADI core which is what I use is rated at 260# seat and 650# open spring pressure. It is actually stronger than the 1050 steel core. Both of these cams are 1 pc and will run OEM fuel pump and any type of distributor gear.

Cstraub69

Tuning at the "black dyno" or where you are on the sands is the final for dialing in a combo. I feel time can be saved by designing and building a combination based on what the demands are that the engine needs to meet. The camshaft is the brain of the engine and through calculation based on engine, rpm, induction, and exhaust the cam can be correctly built the first time out. This saves time and money!!!

roger3

Wow, I hadn't thought about tuning the exhaust. We did that in college in a lab on a single cylinder engine. It was pretty neat, we had a pipe in a pipe exhaust that we could extend or shorten with the engine running at constant speed and that would increase or decrease shaft torque. Seems like for our setup the optimum length was about 12 feet. I'll start reading up on it, probably still have my Notes, but that was in the 80's.

I have an MSD distributor with the Melonite gear so that should be fine.

Like my original post says my biggest goal is piece of mind to avoid lifter failures that I have read about too often. Might not have never happened, but I was worried so here we go.

Just getting over the flu and bronchitis, it's been a miserable week, but I'm starting to feel better and might even get the chance to do some test and tune this weekend.

Cstraub69

Cam numbers. Once a customer has bought a cam from me it is his. He is free to post the numbers. One just needs to understand, I have nothing on the shelf for cams, well maybe 1 LS that is headed to Australia. Everything I do is one off per customer. There is no magic BBC cam that powers everything. Being humans we all want something a little different and each one of my customers gets something a little different.

roger3

Update:

Got hydraulic roller cam installed

Cam numbers at .05
Intake .365 lift and 222 duration
Exh is .347 lift and 228 duration
108 centerline

Dynoed Engine and got these numbers:

515 Peak HP @ 5700 RPM
Straight 2" diameter Headers, no air cleaner, 35 Deg Timing
Do the air/fuel ratio numbers look like the mechanical fuel pump is not keeping up enough for the drag strip? At first glance I did, but looking at them again, I don't think so.


517 Peak HP @ 5600 RPM
Straight 2" diameter Headers, with air cleaner, 37 Deg Timing


506 Peak HP @ 5400 RPM
Hooker 2" diameter Side Headers, with air cleaner, 37 Deg Timing


I wanted to make a couple pulls with the side pipes and inserts but we couldn't connect the exhaust hoses to get the fumes out the building.

The engine ran really smooth. The hp and torque curves were nice and smooth.

Once we put hooker headers on, we didn't have a spot for the a/f meters so the numbers aren't any good.

For comparison here's a dyno pull with the old solid roller cam with no air filter, and 2" diameter straight headers.


Thanks,

Roger

rponfick

Roger, thanks for the data. The cam I am installing from Straub is very close to your's. I hope I can get near the same mid-range torque figures you got.

Still working on measuring pushrod length on mine.

Ralph

gkull

The exhaust gas temps in the first sheet are way out of bounds. also look at the high 14:1 A/F ratio That run should have been for carb jetting comparisons only.

One big notible I see is the left side - right side A/F ratio. Your motor really requires staggered jetting. The dyno people were never on top of the tune and run 3 didn't have the A/F ratio sensors running is why it was at 8.99.

the old solid roller tune really sucked. a two point A/F difference between sides.

Staggered jetting is just having bigger jetting on different corners of the carb. What don't these dyno guys understand?

roger3

Ralph,

What engine combo you using (cu inch, heads, intake, and carb)?

Roger

rponfick

Roger, '69 427 tri power, Brodix Racerite rectangular port heads, stock GM intake and stock exhaust manifolds. Straub cam with 220/235 duration at .05, .571/.529 lift, 108 lobe sep..

Ralph

Cstraub69

Roger,
Well what do you think? Nice torque numbers. I cant remember how big the solid roller was. how was the throttle response? How was she to start? How about the idle?

Chris

gkull

I run the dyno at the shop. One thing that changed many years ago was no more numbers chasing. running something with no air filter and some shop dyno headers does the customer no good.


You want real world numbers with how it is on the car and the dyno session is more of a dyno tune. So they can sort out your combination and it is ready do go when you leave the shop.

roger3

Chris,

I'm very happy. Motor started up and ran great. Idled very nice. I don't have it in my car yet.,hopefully I can put it in this weekend and see how it runs on the street. It'll be a couple of weeks before I get it to the track and see how it does in the 1/4 mile.

I can't thank you enough for helping me. I know I called with several questions, hope it wasn't too much of a bother. It was a learning experience for me. I would definitely recommend you to anyone looking for a cam and/or selecting parts.

I'll keep you updated on its street manners and track performance.

Thanks

Roger

Cstraub69

I have had several worried about my tight lobe seps. Compared to old school stuff how did you like it?