Thread: New engine tune/edelbrock/bog

Tweet

Your half dead 350's probably didn't have a 230/230 cam killing the bottom end. Any cam that you put in the motor has a dedicated 3000 to 3500 rpm operating range, like 1000 to 4250 (that will spin the tires)......or 1500 to 4750...... or 2000 to 5250...... or 2500 to 5750......or 3000 to 6250......or 3250 to 6500......or whatever.

Here's the verbage from Crane Cams concerning their 230/230 flat tappet hydraulic cam characteristics.......
Performance usage, good mid and upper RPM HP, bracket
racing; Street, Heavy, etc., auto trans w/3000+ converter,
oval track; Street Stock, Enduro, Hobby, etc., 1/4-3/8 mile,
serious off road, 10.0 to 11.5 compression ratio advised.

3000+ means 3500. And I doubt seriously that your motor has between 10.0 and 11.5:1 static compression ratio. Do you know the static compression ratio? Do you know the squish/quench?

The camshaft is not a stand-alone part. It must be coordinated with all the other parts of the car, such as static compression ratio, intake manifold design, carb size, weight of the car or truck, torque converter stall, number of gears in the transmission and their ratios...... and differential gear ratio.

Your 230 cam needs (ideally) 10.75:1 static compression ratio, 3500 stall converter (to get the motor up past the dead zone) and some rear gears up into the 4's. Problem with such a static compression ratio is that with iron heads, the motor will be prone to detonation on pump gas. The generally agreed upon limit for iron heads on pump gas is about 9.5:1. For static compression ratios above that, aluminum heads would be highly recommended.

Bottom line: You have over-cammed the motor.
.

Originally Posted by 93F250

Over 3500k it hauls and putting around its ok but give it too much gas and get into the secondaries and it bogs or stumbles then starts to pick up.

Originally Posted by techinspector1

3000+ means 3500. And I doubt seriously that your motor has between 10.0 and 11.5:1 static compression ratio. Do you know the static compression ratio? Do you know the squish/quench?

Bottom line: You have over-cammed the motor.

Tech's spelled it out clearly, and your post actually says that the engine is doing pretty much what it should be doing, but would likely be stronger if your compression ratio was boosted and you were running aluminum heads and high octane gas to handle detonation. Seems like you've got some changes in your future, but you need to know your base before you start throwing more $$$ into the pit. Assuming your screen name (93F250) is the vehicle in question, dropping a SBC into a Ford truck is where your problems started..... (just kidding, just kidding).

To be completely clear it does not matter what rpm it is in if the truck is floored it bogs. If its been floored for a sec let up for a couple sec then floor it, it will bog.

Originally Posted by rspears

Tech's spelled it out clearly, and your post actually says that the engine is doing pretty much what it should be doing, but would likely be stronger if your compression ratio was boosted and you were running aluminum heads and high octane gas to handle detonation. Seems like you've got some changes in your future, but you need to know your base before you start throwing more $$$ into the pit. Assuming your screen name (93F250) is the vehicle in question, dropping a SBC into a Ford truck is where your problems started..... (just kidding, just kidding).

Ahaha i get that a lot. Screen name is my first truck and my screen name on every forum ever. Still have it and it def wont be getting a chevy engine lol.

This set up is actually in an 84 k10 but the hot rod and car sites have better engine tech

Originally Posted by techinspector1

Your half dead 350's probably didn't have a 230/230 cam killing the bottom end. Any cam that you put in the motor has a dedicated 3000 to 3500 rpm operating range, like 1000 to 4250 (that will spin the tires)......or 1500 to 4750...... or 2000 to 5250...... or 2500 to 5750......or 3000 to 6250......or 3250 to 6500......or whatever.

Here's the verbage from Crane Cams concerning their 230/230 flat tappet hydraulic cam characteristics.......
Performance usage, good mid and upper RPM HP, bracket
racing; Street, Heavy, etc., auto trans w/3000+ converter,
oval track; Street Stock, Enduro, Hobby, etc., 1/4-3/8 mile,
serious off road, 10.0 to 11.5 compression ratio advised.

3000+ means 3500. And I doubt seriously that your motor has between 10.0 and 11.5:1 static compression ratio. Do you know the static compression ratio? Do you know the squish/quench?

The camshaft is not a stand-alone part. It must be coordinated with all the other parts of the car, such as static compression ratio, intake manifold design, carb size, weight of the car or truck, torque converter stall, number of gears in the transmission and their ratios...... and differential gear ratio.

Your 230 cam needs (ideally) 10.75:1 static compression ratio, 3500 stall converter (to get the motor up past the dead zone) and some rear gears up into the 4's. Problem with such a static compression ratio is that with iron heads, the motor will be prone to detonation on pump gas. The generally agreed upon limit for iron heads on pump gas is about 9.5:1. For static compression ratios above that, aluminum heads would be highly recommended.

Bottom line: You have over-cammed the motor.
.

Unfortunately i didnt build the package i just got a good deal on it. Its a lunati cam and they recommend a 2500 stall, the b&m is supposed to be 2400 but its more like 2 and it will flash to 2200 sometimes. Would that reslly cause the bog? Should i jumo to a 3500 then? This b&m is junk anyways in my opinion.

I was told the compression was brought up from stock but not by alot.

One of my next purchases will be alumunim heads from blueprint but for the time being i need to get this combo running best i can.

Ive driven rigs with a 350 and similar set ups (too big a cam for the heads). Im almost positive i have it tuned wrong or the secondaries are opening too soon. Its not where it could be with the set up it has now. Heads and torque converter are next though