[TAQuest]

Originally Posted by Cliff R

I don't make the lifters or am I part of the quality control checking process, so it's outside of my control. They let just enough "tickers" slip thru that it's hit and miss with hydraulic lifters, especially since they sent production to Mexico, Korea and China couple of decades ago....FWIW

It is NOT comparable at all, 400 CID at 10 to 1 vs 455 CID at 10 to 1. The larger engine requires considerably MORE camshaft to basically do the same thing as far as dynamic compression is concerned. It's the laws of physics with these things, and something I've learned to work with over the years when selecting parts and tuning these engines.

Having to add two cans of 108 octane boost to a tank to give you a warm and fuzzy with pump gas simply means that you should have chosen the 2801 cam instead of the 2800. Adding 10 degrees duration would lower dynamic or effective compression in a 400 built effectively by close to a full point.......IMHO......Cliff

I meant it was comparable that I have a 400 with 72 cc heads and he has a 455 with 87 cc heads.

You can't argue with success. I'm in the real world with an engine I just fixed to run excellent! And it's with a cam many said was no good. Ironically, the cam that was recced here was junk and didn't work. I'm not talking on paper now, my car is real. Real recent experience.

[Cliff R]

I run more compression in my engines and fine on pump gas. Even the current engine which maths out at 11.3 to 1 compression is just fine on pump gas. We even run 87 octane in it w/o any detonation anyplace. Didn't do that on purpose, had my son working here for a while and he was filling the gas cans with 87 octane when we sent him on parts runs.

I noticed one really hot/humid summer day the engine "ran-on" after shut down when fully heat soaked. Did a little checking, timing was spot on, just thought I got some bad gas. It happened again so I questioned my son, and said he'd been filling up the truck and gas cans with 87 octane....yikes!.......Cliff

[TAQuest]

Originally Posted by glhs#116

I will definitely give that a try for giggles. I am at 1/2 turn preload at present..

Sam

I tried up to 1 full turn and nothing changed. When you get a good cam and lifters that match your heads 3/4 turn will work just fine.

[TAQuest]

Originally Posted by Cliff R

I run more compression in my engines and fine on pump gas. Even the current engine which maths out at 11.3 to 1 compression is just fine on pump gas. We even run 87 octane in it w/o any detonation anyplace. Didn't do that on purpose, had my son working here for a while and he was filling the gas cans with 87 octane when we sent him on parts runs.

I noticed one really hot/humid summer day the engine "ran-on" after shut down when fully heat soaked. Did a little checking, timing was spot on, just thought I got some bad gas. It happened again so I questioned my son, and said he'd been filling up the truck and gas cans with 87 octane....yikes!.......Cliff

Good for you Cliff!

You should try some racing fuel. You will get substantially more power with more octane. Give it a try and you will never go back to the cheap stuff. I like the 110 the best. Price doesn't matter, we don't put more than a tank a week in it.

[TAQuest]

Originally Posted by Formulajones

That cam was in no means ever intended for a big 455 with 10.5:1 compression.

Edelbrock Performer-Plus Camshaft # 2157 is designed for 350-455 Pontiac V8 engines and produce optimum torque from the low-end to the mid-range.

[Cliff R]

Last outing at Norwalk I put in 5 gallons of race gas and the car slowed .04-.05 seconds. If your engine has the correct effective duration for lower octane, putting in higher octane and slowing down the burn rate also kills off some power.

This entire thing is about effective compression, cylinder filling abilities across the loaded RPM range, combustion efficiency, quench distance, BSFC, close control of timing/fuel curves and about a dozen other things right down to vehicle weight and torque converter efficiency that effect octane requirements.

It's WAY beyond just throwing in camshaft A into engine B, setting the timing by ear, and hoping you get good results and can get it to work on currently available pump fuel......FWIW.

Even with that said, at the end of the day if you are happy with the end results and found a way to get there, and can deal with the expense and limited availability of high octane fuel/additives in a street driven vehicle......good for you........Cliff

[Cliff R]

Edelbrock doesn't make or design camshafts. The 2157 is nothing more than the "RV" grind that's been available for at least 4 decades for just about every brand/make/type of engine out there. It's sold under at least a dozen labels, and those selling it will often change the specs ever so slightly to make it look like their own grind.

It's a decent cam in a 350CID build around 8.5 to 9 to 1 compression. Above that one can very quickly run into detonation issues, and below that engine power gets a little "soggy" down low.....Cliff

[TAQuest]

Originally Posted by Cliff R

Last outing at Norwalk I put in 5 gallons of race gas and the car slowed .04-.05 seconds.

That's obviously because you have it detuned for crappy fuel.

It doesn't take a rocket scientist to know that more octane has more power potential if tuned correctly for it.

[TAQuest]

Originally Posted by Cliff R

Edelbrock doesn't make or design camshafts. The 2157 is nothing more than the "RV" grind that's been available for at least 4 decades for just about every brand/make/type of engine out there. It's sold under at least a dozen labels, and those selling it will often change the specs ever so slightly to make it look like their own grind.

It's a decent cam in a 350CID build around 8.5 to 9 to 1 compression. Above that one can very quickly run into detonation issues, and below that engine power gets a little "soggy" down low.....Cliff

It just so happens that that particular cam has great results with the heads Sam and I have. We both had bad results from the 703 cam with these heads. Coincidence? Maybe. I don't believe much in coincidences but they do happen rarely.

Edelbrock took the time and tested the combo and proved it on the dyno. I'm living it. Not just a theory.

[Formulajones]

Originally Posted by TAQuest

Edelbrock Performer-Plus Camshaft # 2157 is designed for 350-455 Pontiac V8 engines and produce optimum torque from the low-end to the mid-range.

That just means it'll fit engines with the same architecture, doesn't mean it's the right choice

That is an extremely tiny cam with 204 @ .050. The factory 068 is a bigger cam than that. Sticking that performer cam in even a 400ci is going to give you detonation issues with any amount of decent compression which is why you find it necessary to run expensive race gas and fuel additives.

That's just not an option for us car guys that actually drive our cars even just sparingly, let alone frequently. We used to build engines that way decades ago when race gas was still $3 a gallon but these days at $8 a gallon it makes no sense when we can build pump gas engines to make as much power and spend 1/4 the cost in fuel, not to mention I can drive it anywhere and fill it up anywhere.

[Formulajones]

Originally Posted by TAQuest

That's obviously because you have it detuned for crappy fuel.

It doesn't take a rocket scientist to know that more octane has more power potential if tuned correctly for it.

That is absolutely completely false.

If the engine is built properly, with the right camshaft and compression, it'll run perfectly fine on pump gas in all conditions without the need to detune.

I have several real world examples here, as Cliff does, and many others on the forum here.

I'm running an 11:1 compression engine with iron heads on 91 octane here, with 36 degrees total timing and it runs absolutely perfect on pump gas and is driven daily.

My bird is a stock RAIII 400 that has 10.13:1 compression and the stock 068 cam in it. Much like your claimed original 69 bird, very similar engine. It's not detuned at all, loves 34 degrees total timing and runs on 91 octane. With stock converter and only a 3.31 gear has gone 13.10 @ 104.5 mph. I drive this thing everywhere on pump gas, no additives.
Race gas does nothing for this car, I've tried it. If the engine doesn't need it, it's wasted money.

[TAQuest]

Originally Posted by Formulajones

That just means it'll fit engines with the same architecture, doesn't mean it's the right choice

That is an extremely tiny cam with 204 @ .050. The factory 068 is a bigger cam than that. Sticking that performer cam in even a 400ci is going to give you detonation issues with any amount of decent compression which is why you find it necessary to run expensive race gas and fuel additives.

That's just not an option for us car guys that actually drive our cars even just sparingly, let alone frequently. We used to build engines that way decades ago when race gas was still $3 a gallon but these days at $8 a gallon it makes no sense when we can build pump gas engines to make as much power and spend 1/4 the cost in fuel, not to mention I can drive it anywhere and fill it up anywhere.

To each his own. I can drive mine anywhere and fill it up anywhere too. That's why I switch to octane booster when I'm not near the racing fuel pump.
If you can't afford to spend an extra $15(2 octane boosters) on a tank of gas in your fun car I understand that too. Everyone has to live within their budget. I think that a few extra dollars an hour of fun isn't much these days. I drop the pizza guy a $10 tip. If he's worth it so am I.

So I will add the caveat, if you can't afford to spend an extra $15 on a tank of gas don't build a engine like mine, do something different to save your all that money.

[ta man]

Originally Posted by TAQuest

That's obviously because you have it detuned for crappy fuel.

It doesn't take a rocket scientist to know that more octane has more power potential if tuned correctly for it.

Not sure about that, for most here why would we want to "tune" for high octane..basically setting up our engines to have unmanageable higher compression ratios when readily available pump gas will get the job done running lower compression ratios.
If I remember correctly lower octane fuel actually produces more energy.

[TAQuest]

Originally Posted by Formulajones

My bird is a stock RAIII 400 that has 10.13:1 compression and the stock 068 cam in it. Much like your claimed original 69 bird, very similar engine. It's not detuned at all, loves 34 degrees total timing and runs on 91 octane. With stock converter and only a 3.31 gear has gone 13.10 @ 104.5 mph. I drive this thing everywhere on pump gas, no additives.
Race gas does nothing for this car, I've tried it. If the engine doesn't need it, it's wasted money.

I would ever do this with my concourse 69 numbers matching RAIII 400 Firebird Convertible. It's worth WAY too much to penny pinch like that. Better look at your plugs ….

[Formulajones]

Originally Posted by TAQuest

I would ever do this with my concourse 69 numbers matching RAIII 400 Firebird Convertible. It's worth WAY too much to penny pinch like that. Better look at your plugs ….

Plugs look perfect, no signs of detonation anyplace. Been racing and daily driving this combo going on 3 years now.

[Steve C.]

Pump Gas Versus Race Gas

Is Race Gas Worth Any Power On A Pump-Gas Street Engine? We Put It To The Test.

https://www.hotrod.com/articles/0901...pump-race-gas/


The problem running race gas is that if you don't have the compression to compress the fuel and air enough, you'll actually run SLOWER!

http://www.badasscars.com/index.cfm/...rod/prd427.htm

Everything You Need To Know About Octane
http://www.superchevy.com/how-to/car...w-about-octane




.

[Formulajones]

Originally Posted by TAQuest

To each his own. I can drive mine anywhere and fill it up anywhere too. That's why I switch to octane booster when I'm not near the racing fuel pump.
If you can't afford to spend an extra $15(2 octane boosters) on a tank of gas in your fun car I understand that too. Everyone has to live within their budget. I think that a few extra dollars an hour of fun isn't much these days. I drop the pizza guy a $10 tip. If he's worth it so am I.

So I will add the caveat, if you can't afford to spend an extra $15 on a tank of gas don't build a engine like mine, do something different to save your all that money.

It's not that people can't afford it, it's the fact that it's not necessary if the engine is built and tuned properly. No one wants to carry around a case of octane booster all the time, and most believe it's a snake oil product anyway.

If you're happy doing it, that's your deal. We drive our stuff on several hundred mile trips, sometimes out of state, even drive to and from the dragstrip and beat on it all weekend. I don't need to worry about what kind of gas I'm putting in nor do I want to bother with running to the store and carrying around octane booster everywhere I go. Shucks I didn't even know people still do that these days, lol. I get in, fill the tank with 91, and drive.

Hell, dad's running a 571 ci Pontiac that dyno'd at 724hp 764 tq on 91 octane. 10.84:1 compression, he drives it everyplace, races it, beats on it. Been running for I guess going on 4 or 5 years now. Nothing but pump gas and no additives.

[NeighborsComplaint]

Originally Posted by Steve C.

Pump Gas Versus Race Gas

Is Race Gas Worth Any Power On A Pump-Gas Street Engine? We Put It To The Test.

https://www.hotrod.com/articles/0901...pump-race-gas/.

Those amateurs at Westech obviously don't have the hearing acuity of TAQuest. Neither does Cliff. He walks around with a book full of notes and timeslips and can't hear that his car is actually making more HP on race gas. lol

I have summarized the important steps to tuning by ear for performance and drivability below.

[NeighborsComplaint]

Sorry to the OP for derailing this thread momentarily. Hope you can locate the source of the noise.

[Cliff R]

"Tuning by ear" is the major reason Dave at SD builds his engine with about a full point compression less than we do. He's had a few of his customers take his engines and let the next door neighbors ex-wife's third cousins live in boyfriend come over and turn the distributor until it sounded better. Everyone is happy for about an hour until all the rod bearings end up in the oil pan.....then they call Dave and start bellyaching about his engine work........FWIW.

I build my engines with higher compression, we also do the carbs and distributors for them. We dyno test them, set the timing/fuel curves for best numbers, then deliver them to the customer along with our exclusive "Arkansas Warranty":

IF you break it in half..............................you get BOTH halves!....LOL.......Cliff