[Skip Fix]

Dave thanks for posting . Even though my RAIV motor liked the reverse split cam my E head 500" with a 268/272 solid roller liked tighter lash on the exhaust telling me it would have liked more on the exhaust. My 470/409 did not like more ratio on either side or tighter loose lash.

I think unless you put multiple cams in the same motor, try different ratios on the same motor, tighten loosen lash on the same motor you really don't know what it really likes. Why the stockers have shelves full of cams(can convertors )

[PAUL K]

Good thread and a lot of good information. However, I feel you need to match the cam with the parts you are using and you will generally need a tighter lobe separation than 114 if you're looking for cutting edge performance. However, I cannot stress how important it is to match all the components! The new norm is 10 second naturally aspirated pump gas street cars.

In 2006 I was running my 80 T/A with a 9.1 compression 455, ported cast iron heads, 3.42 gears, tight 11" Coan 2800 rpm converter and a Comp hydraulic roller 242/248 with an 110 LSA. Weighing over 3900 lbs. the best ET was 11.35 @ 119.3 mph.

For the last 2 years I've been running the same 3.42 gears, the car has lost 100 pounds and uses 318 cfm E-heads, Torker II and a tight 10" converter with a solid roller 259 @.050 on a 108 LSA, I've only had it to the track 3 times but have run consistent 10.7 @125 mph.

A friend was running a 9.1 455 with E-heads, 10" inch converter and 3.55 gears in a '64 GTO weighing 3670 lbs. and has run 11.2 @ 119 mph using the dreaded Comp XR288HR which has a 110 LSA.

My brother ran a 9.1 compression 455 with 310cfm E-heads, a solid roller with 254 duration @ .050 ground on a 108 LSA, and went 10.8 @ 124 mph the first time out, using a tight 10"
converter, 3.70 gears and weighing 3720 lbs.

[ta man]

Originally Posted by Will

You have a good point and this kind of thing drives me nuts. People are so afraid to use a good quality converter yet it's probably in the top 3 "best bang for the buck" mods you can make to any performance oriented car.

With a good quality converter you can truly have your cake and eat it too. I remember having conversations like this with guys - I'd tell them my car had a 3200 stall converter in it and they'd start off with the "I'd never run something like that in my car" and just wouldn't listen even when I explained that it drove just like stock in normal driving.

OTOH, it's okay if people want to be close minded about this kind of stuff. That makes it easier for those of us in the know to impress them with the great track performance of our street cars and leave them scratching their heads trying to figure out how we do it...

The average car guy has no clue how a good convertor is supposed to work..I also run a Continental 10 inch "Jim Hand" special......Had it in service for 12 years now...Worth every penny...

[ponyakr]

"...The new norm is 10 second naturally aspirated pump gas street cars..."



Wow, it's the "norm" to have 10 sec street cars ! It may be the "norm" where you live. But in my area, there are lots of dedicated (race only) bracket cars still running 11's.

I can hardly imagine driving around on hard street tires, in a 10 sec car. Is this some sort of a status symbol for guys with the $$ to do it ?

I'm not badmouthing anybody. Hey, if I had more money, I'd spend most of it on racing Pontiacs. But I still would not try to drive a 10 sec car on the street. There are 12 sec cars that will make all the tire smoke you want. And street racing is illegal, ain't it ?

[i82much]

Originally Posted by ta man

Its around...check out the new best with 3.08 gearing thread..think its there.

Nice ride. I was really curious what intake and cam you were running. I have a Torker II and am considering trying an RPM intake and/or widening my lobe sep to a 112 or 114. Also considering a hydraulic roller or staying with a solid roller.

My car absolutely screams once it gets some RPM, but it is a little doggy just off-idle. I have a stick and you can kind of feel it want to pull the engine down when you pull out in traffic. Swapping from an open to a four hole spacer on the T2 helped but not as much as I'd like.

[Dave Bisschop]

Originally Posted by Skip Fix

Dave thanks for posting . Even though my RAIV motor liked the reverse split cam my E head 500" with a 268/272 solid roller liked tighter lash on the exhaust telling me it would have liked more on the exhaust. My 470/409 did not like more ratio on either side or tighter loose lash.

I think unless you put multiple cams in the same motor, try different ratios on the same motor, tighten loosen lash on the same motor you really don't know what it really likes. Why the stockers have shelves full of cams(can convertors )

I learned many years ago that just because you find a result in one combo doesn't mean it applies to others, that's what keeps things interesting and makes you realize you will never know it all which is great!!! I found with our 65 GTO race car years ago that the optimum ICL changed when I went from 1 3/4 to 2" headers. Just changing the headers didn't do much, but revisiting the cam timing showed the cam wanted to be backed up 4 deg from where it was optimum with 1 3/4".

I've been involved with several NHRA Stock Eliminator racers and they all use tighter lobe seps to produce some impressive power with unported heads, but a HUGE factor why these cars perform as they do is that everything is optimized in the entire drivetrain which requires $$$$. One customer with a legal 77 bird has gone 11.27 @ 117mph with a completely legal 350 Pontiac and only .363" valve lift, but I think he has more in the trans than the entire engine!! so you can't really compare what these cars do to your average street/strip car.

[Dave Bisschop]

Originally Posted by PAUL K

Good thread and a lot of good information. However, I feel you need to match the cam with the parts you are using and you will generally need a tighter lobe separation than 114 if you're looking for cutting edge performance. However, I cannot stress how important it is to match all the components! The new norm is 10 second naturally aspirated pump gas street cars.

In 2006 I was running my 80 T/A with a 9.1 compression 455, ported cast iron heads, 3.42 gears, tight 11" Coan 2800 rpm converter and a Comp hydraulic roller 242/248 with an 110 LSA. Weighing over 3900 lbs. the best ET was 11.35 @ 119.3 mph.

For the last 2 years I've been running the same 3.42 gears, the car has lost 100 pounds and uses 318 cfm E-heads, Torker II and a tight 10" converter with a solid roller 259 @.050 on a 108 LSA, I've only had it to the track 3 times but have run consistent 10.7 @125 mph.

A friend was running a 9.1 455 with E-heads, 10" inch converter and 3.55 gears in a '64 GTO weighing 3670 lbs. and has run 11.2 @ 119 mph using the dreaded Comp XR288HR which has a 110 LSA.

My brother ran a 9.1 compression 455 with 310cfm E-heads, a solid roller with 254 duration @ .050 ground on a 108 LSA, and went 10.8 @ 124 mph the first time out, using a tight 10"
converter, 3.70 gears and weighing 3720 lbs.

For many years most of the street/strip stuff we built was 108-110 lobe seps and we made good power, but when we started going to wider lobe seps over 15 years ago we found we could get much better driveability, way less "stink" out the tail pipes and extend the rpm range, this was with flat tappet solid lifter cams. For most of the solid roller race stuff we still used 106-108 as we only had cast cranks to work with but once the forgings became available we started going to wider lobe seps and in a lot of cases less duration and ended up with more power and quicker ET's at the track with more rpm capability. I feel a lot of the gains we've seen with the wider lobe seps also has to do with the increased efficiency with the cylinder heads. No doubt you can make some great power with the tighter lobe sep cams (we ran a 104 LSA in our 65 GTO), but I found at some point you will hit a wall. I disagree with your statement that today's cutting edge performance is made with tighter lobe seps, the guys making big NA power are using wide lobe sep cams and turning big rpm to make the power they do and this isn't specific to Pontiacs.

I do agree with you 100% that whatever route you decide to take matching all the drivetrain components is critical to achieving optimum performance. This typically takes time at the track to sort out all the details, ta man is a good example of that. You can't just keep throwing parts at something if you never optimize what you already have and make incremental changes which in some cases might make things go backwards before you can go forward, but if you make too many changes all at once you will never really know which ones are helping or hurting.

[Skip Fix]

I think Paul was just saying with today's better flowing heads it is not that hard to get a 455 Pontiac in the 10s and even be a fairly mild streetable car. My pump gas motor in the 78 TA can do it with good air(the hard part in Houston) and my light wheels no spare 3750 lbs. It is easily reproducible and even has a HFT cam that pulls plenty of vacuum for power brakes. 320 cfm round port E heads, Torker II I did spend a lot of time blending and had to raise the roof, out of the box Holley 850 DP-one jetting leaner, 2" Hooker Super comps into a 3" X and mufflers and full tailpipes. 9" slicks and a 10" Continental Convertor. No Caltracs, slapper bars just some front half biased springs.

[PAUL K]

Originally Posted by ponyakr

"...The new norm is 10 second naturally aspirated pump gas street cars..."



Wow, it's the "norm" to have 10 sec street cars ! It may be the "norm" where you live. But in my area, there are lots of dedicated (race only) bracket cars still running 11's.

I can hardly imagine driving around on hard street tires, in a 10 sec car. Is this some sort of a status symbol for guys with the $$ to do it ?

I'm not badmouthing anybody. Hey, if I had more money, I'd spend most of it on racing Pontiacs. But I still would not try to drive a 10 sec car on the street. There are 12 sec cars that will make all the tire smoke you want. And street racing is illegal, ain't it ?

I gave up running BF goodies when my car broke broke into the 11's.

As far a spending money I agree with you , but there have been a lot of sets of $500 billet valve covers sold! Although I've never bought any.

The status symbol we are seeing around here is 1000 horsepower to the rear wheels!

[ponyakr]

"...The status symbol we are seeing around here is 1000 horsepower to the rear wheels!"



Yeah, I can see where that would come in handy if a ricer pulled up beside you, and revved up his engine.

[PAUL K]

"I disagree with your statement that today's cutting edge performance is made with tighter lobe seps, the guys making big NA power are using wide lobe sep cams and turning big rpm to make the power they do and this isn't specific to Pontiacs."



I agree, the trend is to spread the lobe centers on high RPM big power engines and extend the exhaust duration. I was thinking of this when I was typing my original post, but that is mostly for high rpm race engines.

I have not seen many Pontiacs running in the ten's with 114 LSA's, if there are some examples out there I would like to hear about your combinations. Please list them.

[Dave Bisschop]

Originally Posted by PAUL K

"I disagree with your statement that today's cutting edge performance is made with tighter lobe seps, the guys making big NA power are using wide lobe sep cams and turning big rpm to make the power they do and this isn't specific to Pontiacs."



I agree, the trend is to spread the lobe centers on high RPM big power engines and extend the exhaust duration. I was thinking of this when I was typing my original post, but that is mostly for high rpm race engines.

I have not seen many Pontiacs running in the ten's with 114 LSA's, if there are some examples out there I would like to hear about your combinations. Please list them.

I'm not suggesting everyone run out and slide 114 lobe sep cams in their engine. The reality is lobe sep isn't really what we should be looking at as overlap, valve opening and closing events is really what should be looked at and the lobe sep ends up being what it is, but of course when spec'ing a cam and choosing the lobes to run part of placing the cam order is to specify what LSA the cam should be ground on, trying to remember all those events off the top of your head for bench racing discussion would get a little confusing. About 95% of my customer base is street/strip guys, about 6-7 years ago when the economy was booming we had a lot more customers building higher end larger engines, but most still wanted pump gas as they wanted to drive their cars on the street.

We spent a bunch of time and money doing R&D on 535-541 pump gas combo's using Marcel's 541 shortblock as a test mule. In the end his engine with a set of our wide ports and a 276/286 @ .050" 114 lobe sep cam, ported 4500 Victor intake etc. produced 826hp on pump gas with 10.8 to 1 compression. He put the engine in his 81 Lemans street car and ran as quick as 9.68 @ 140ish mph with a race weight of 3920lbs (car still has PW, full interior etc.). The car was very difficult to get down the track with more aborted runs than good ones as he typically ran it at street legal events on 10" slicks, but when the track was good it did run a bunch of 9.70's-80's. Not a great true street combo so we are working on a new combo with a big hyd. roller that should still put the car into the 9's with good conditions but be a lot more street friendly.

Before the 541 Marcel ran a 10.6 to 1 468 with a set of 310cfm hand ported E-heads, 271/279 @ .050 .675"lift 112 lobe sep solid roller in his 81 Lemans which had a race weight at that time of around 3800lbs, the car ran consisitent mid 10's with a best of 10.43 @ 127+mph and he drove the car on the street a lot at that point.

A few years ago a customer with a stock weight, stock wheel well 66 GTO wanted to have a super low maintenance engine to run in the mid 10's. He wasn't concerned with pump gas and actually preferred to run race gas as he was worried about the quality of fuel at the pump so we built a 505 with flat top pistons and a set of our 340-350cfm E-heads and ported 4150 Northwind intake. For a cam we used a 252/262 hyd. roller .608"/.638" gross valve lift 114 lobe sep with 857 hyd. roller lifters (old style), Compression is a hair over 12 to 1. Intake is topped off with a Pro Systems 1000cfm HP 4150 carb. The engine effortlessly made 752hp on the dyno and shifted @ 5800rpm lays down 10.0's 10 teens and if he shifts it at around 6400-6500rpm runs into the 9's. This is right off the trailer and there hasn't been any need to do any tweaking since the car is only legal for 10 flat. He runs a TH400 4000 stall ATI conv. and 3.73 gears with a 28" tall slick, race weight is around 3500lbs. This same combo at 461-474ci using a stock block and 10.75 to 1 would easily run mid to low 10's also.

These are just a few I can think of off the top of my head. I wasn't disputing that you can run quick with the tighter lobe seps, but a street/strip car with wider lobe sep cams (read less overlap) will run cleaner and have a broader less peaky rpm range.

[PAUL K]

Originally Posted by Dave Bisschop

I'm not suggesting everyone run out and slide 114 lobe sep cams in their engine. The reality is lobe sep isn't really what we should be looking at as overlap, valve opening and closing events is really what should be looked at and the lobe sep ends up being what it is, but of course when spec'ing a cam and choosing the lobes to run part of placing the cam order is to specify what LSA the cam should be ground on, trying to remember all those events off the top of your head for bench racing discussion would get a little confusing. About 95% of my customer base is street/strip guys, about 6-7 years ago when the economy was booming we had a lot more customers building higher end larger engines, but most still wanted pump gas as they wanted to drive their cars on the street.

We spent a bunch of time and money doing R&D on 535-541 pump gas combo's using Marcel's 541 shortblock as a test mule. In the end his engine with a set of our wide ports and a 276/286 @ .050" 114 lobe sep cam, ported 4500 Victor intake etc. produced 826hp on pump gas with 10.8 to 1 compression. He put the engine in his 81 Lemans street car and ran as quick as 9.68 @ 140ish mph with a race weight of 3920lbs (car still has PW, full interior etc.). The car was very difficult to get down the track with more aborted runs than good ones as he typically ran it at street legal events on 10" slicks, but when the track was good it did run a bunch of 9.70's-80's. Not a great true street combo so we are working on a new combo with a big hyd. roller that should still put the car into the 9's with good conditions but be a lot more street friendly.

Before the 541 Marcel ran a 10.6 to 1 468 with a set of 310cfm hand ported E-heads, 271/279 @ .050 .675"lift 112 lobe sep solid roller in his 81 Lemans which had a race weight at that time of around 3800lbs, the car ran consisitent mid 10's with a best of 10.43 @ 127+mph and he drove the car on the street a lot at that point.

A few years ago a customer with a stock weight, stock wheel well 66 GTO wanted to have a super low maintenance engine to run in the mid 10's. He wasn't concerned with pump gas and actually preferred to run race gas as he was worried about the quality of fuel at the pump so we built a 505 with flat top pistons and a set of our 340-350cfm E-heads and ported 4150 Northwind intake. For a cam we used a 252/262 hyd. roller .608"/.638" gross valve lift 114 lobe sep with 857 hyd. roller lifters (old style), Compression is a hair over 12 to 1. Intake is topped off with a Pro Systems 1000cfm HP 4150 carb. The engine effortlessly made 752hp on the dyno and shifted @ 5800rpm lays down 10.0's 10 teens and if he shifts it at around 6400-6500rpm runs into the 9's. This is right off the trailer and there hasn't been any need to do any tweaking since the car is only legal for 10 flat. He runs a TH400 4000 stall ATI conv. and 3.73 gears with a 28" tall slick, race weight is around 3500lbs. This same combo at 461-474ci using a stock block and 10.75 to 1 would easily run mid to low 10's also.

These are just a few I can think of off the top of my head. I wasn't disputing that you can run quick with the tighter lobe seps, but a street/strip car with wider lobe sep cams (read less overlap) will run cleaner and have a broader less peaky rpm range.

Thanks for posting, good info. I'm not surprised at all the big inch engine responded well to the wider LSA, also not surprised the higher compression engine liked it. Years ago we were running a 455 with an UltraDyne 271/279 .426 LL cam on a 110. When we switched to 108 LSA the car picked up a solid tenth and a half and almost 2 mph.

As far as the last combo mentioned you think a 462ish engine with 10.75 compression would run low ten's with a 252/262 cam?

[Dave Bisschop]

Originally Posted by PAUL K

Thanks for posting, good info. I'm not surprised at all the big inch engine responded well to the wider LSA, also not surprised the higher compression engine liked it. Years ago we were running a 455 with an UltraDyne 271/279 .426 LL cam on a 110. When we switched to 108 LSA the car picked up a solid tenth and a half and almost 2 mph.

As far as the last combo mentioned you think a 462ish engine with 10.75 compression would run low ten's with a 252/262 cam?

There are so many variables that will affect performance, your cam swap obviously showed that the 108 LSA was better suited to the rest of the combo. Does that mean if you had made other changes in the combo that the 110 LSA could have been quicker than the 108? When you did the cam swap did you keep the ICL in the same position? It all goes back to what you said earlier that matching the components is critical. With all the info out there it's fairly easy to get into the ball park, but there are a ton of "grey" areas that require tweaking to get things optimized.

I do believe that a 3500ish lb car all dialed in could run bottom of the 10's with the last combo. Will that happen first time out? I doubt it. Good discussion, if a guy could just do R&D all day everyday!!! Unfortunately that doesn't pay the bills.

[ta man]

Originally Posted by i82much

Nice ride. I was really curious what intake and cam you were running. I have a Torker II and am considering trying an RPM intake and/or widening my lobe sep to a 112 or 114. Also considering a hydraulic roller or staying with a solid roller.

My car absolutely screams once it gets some RPM, but it is a little doggy just off-idle. I have a stick and you can kind of feel it want to pull the engine down when you pull out in traffic. Swapping from an open to a four hole spacer on the T2 helped but not as much as I'd like.

I'm actually doing an intake swap from a untouched Torker 2 to a portmatched Performer Rpm...results will be coming.I've ran the Torker 2 for a few years,last year added a Wilson four hole tapered spacer.It picked up a half a tenth or so versus an open spacer.A normal four hole spacer was the slowest.It will be interesting how the Rpm performs overall..may take a bit to figure out what spacer it likes.I also opening up the Torker 2 intake then reinstalling and running it against the rpm on the same day.

Oh and its great seeing Dave Bisschop posting.....Dave ,Marcel and my wife are the reason why my car runs like it does!A set of surprise heads under the Christmas tree does wonders for performance!

[PAUL K]

Originally Posted by Dave Bisschop

There are so many variables that will affect performance, your cam swap obviously showed that the 108 LSA was better suited to the rest of the combo. Does that mean if you had made other changes in the combo that the 110 LSA could have been quicker than the 108? When you did the cam swap did you keep the ICL in the same position? It all goes back to what you said earlier that matching the components is critical. With all the info out there it's fairly easy to get into the ball park, but there are a ton of "grey" areas that require tweaking to get things optimized.

I do believe that a 3500ish lb car all dialed in could run bottom of the 10's with the last combo. Will that happen first time out? I doubt it. Good discussion, if a guy could just do R&D all day everyday!!! Unfortunately that doesn't pay the bills.

Yes, you are right about someone else paying the bills, while R&D is done!

We ran the 110 LSA for two seasons and tried changing the cam timing several times. It liked tight lash, 1.6 rockers over the 1.5s it ran best about 5 degrees advanced and was running 10.5 @ 127. We swapped the cam and installed it 5 degrees advanced and started with the tight lash. Off the trailer we went mid 10.3 @129. We played with that for a couple of seasons. It didn't make much of a difference moving the cam timing around but it still liked the lash tight so we switched to a UD 275/283 on a 108 and picked up again. Now the engine liked 103 ICL and the lash at .026. We played around with that for a while and ran 10.1 @ 131 mph. The engine was put to the side and after a few years I just freshened it and installed a Comp 280/284 .440 LL cam ground on a 105. I hope to get a chance to test it in my brothers 70 Firebird this year but we are into June already and still behind. I also degreed the old 275 UD so we can swap them easily in the car if we feel we want backwards.

[Cliff R]

"I'm not suggesting everyone run out and slide 114 lobe sep cams in their engine. The reality is lobe sep isn't really what we should be looking at as overlap,"

+2

I saw several posts where folks posted nice number with tighter LSA, but NONE of them were 260 duration advertised cams and 220's @ .050"....NOT going to happen. Those little cams are, and always have been PISS-POOR choices for these engines, at any compression ratio.

What simply happens here is that you take a HUGE undersquare engine, that's already trying to make ALL the power right off idle, then put a cam in it that tries to make it better at what it already does best. Top that off with the excellent cylinder filling abilities of these "short seat timing" cams, and you have just built yourself a Pontiac 455 "turd".

I've had quite a few of these vehicles brought up here to tune, and ALL of them had the same symptoms, "quirky" idle, "stinky" shi@ coming out the pipes, octane sensitive, and did NOT like "normal" timing and fuel curves. Not to mention they didn't make any kind of impressive power, and were DONE before 5000rpms, even with really good flowing heads on them.

I don't know who's been keeping score here? But going from 428hp @ 4900rpms to 514hp at 5900rpms, and 516ft lbs tq to 559ft lbs, better idle, less stinky shi@ out the exhaust, etc is a nice improvement from only changing ONE PART.....IMHO......Cliff

[tpssonic]

"I don't know who's been keeping score here? But going from 428hp @ 4900rpms to 514hp at 5900rpms, and 516ft lbs tq to 559ft lbs, better idle, less stinky shi@ out the exhaust, etc is a nice improvement from only changing ONE PART.....IMHO......Cliff"

I'll toast to that.

Good to hear Dave post as well- I really enjoyed working with him on my build.

Thanks everyone for posting their experiences and knowledge- great thread.

[Cliff R]

+2, love to see Dave take the time to post on here as well. It's always great to see lots of good tech stuff posted, even if it's "googled" up, but even better when it comes from one of the guys who's really making it happen with these things. I like Dave's approach to making power, you can research this stuff to death, but at some point you've got to get your hands dirty and try stuff out to see what works and what doesn't.

We talk on occasion thru emails, but both of us do this for a living so have to spend most of our time in the shop to keep the bills paid and mama happy! I'm blessed with having really good help so it frees me up to spend a little time each day on the Forum. Dave has a full plate with stuff falling off all sides of it, and I think he may be a "one man show" at this point, or close to it?......Cliff

[72LuxuryLeMansLa.]

Originally Posted by Dave Bisschop

I'm not suggesting everyone run out and slide 114 lobe sep cams in their engine. The reality is lobe sep isn't really what we should be looking at as overlap, valve opening and closing events is really what should be looked at and the lobe sep ends up being what it is, but of course when spec'ing a cam and choosing the lobes to run part of placing the cam order is to specify what LSA the cam should be ground on, trying to remember all those events off the top of your head for bench racing discussion would get a little confusing. About 95% of my customer base is street/strip guys, about 6-7 years ago when the economy was booming we had a lot more customers building higher end larger engines, but most still wanted pump gas as they wanted to drive their cars on the street.

These are just a few I can think of off the top of my head. I wasn't disputing that you can run quick with the tighter lobe seps, but a street/strip car with wider lobe sep cams (read less overlap) will run cleaner and have a broader less peaky rpm range.

Dave,

I know it is difficult to boil it down to generalities because each combo is specific, but is there a range for street overlap vs. street/strip vs. strip only that novices can use? For instance I told you I wanted to make in the area of 450hp with my daily driver 433(4"stroke .030" over 400 block) with iron heads and intake, also using RARE manifolds instead of headers and you said the Stump Puller was the cam. In my calculator it has 63.5° of overlap. Would 75° of overlap be way too much? Is ther a sweet spot for manifolds vs. headers? What does it take to figure out how much overlap?

Thanks much for spreading the wisdom!