Cam selection

[bluezone]

I jus received my stroker Short Block back from the machine shop... Now it's time to get the top end together.... I will like for this car to be a nasty street machine & a good track car..

I wanna pull the most out of this Stroker... I will Love to get 700+ to the ground...

Alot of people told me to run a 215/220.. But I have seen some guys running larger cams...

Engine~ 109 "30 over" Gridle with Billet Caps
Cam~ ?????
Turbo~ Billet Turbonetics 76mm BB
Fuel~ Fast System
Heads~ GN1 Aluiminum Heads "Race Port"
Intake~ Champion

 

[jpwalt1987]

I have a 218/218 .540 lift billet roller on my 231. My heads flow "really well"

 

[TurboTR]

Well, pretty much like any other engine, the cam needs to be sized for what you plan to do for optimal results. Do you plan to shift at 6000, or? As the car gets faster it wants to rpm more through the traps too. So gear ratio, cam, converter all play a roll here. A 28" tire with 3:42 rear makes a pretty nice combo for a fast street strip car, running about 6500'ish rpm into the high 130 to 140 mph or so trap speed range. A 210'ish hyd lifter cam being pushed like 6500 rpm through the traps? Way undersized for that for example IMO. And pushing it for hyd valvetrain to boot. Even a 218 hyd is pretty tiny here. When you get into the mid 10's zone and faster the engines really can wake up with better cams (and valvetrain). Assuming you plan to go at least 130 mph trap speed I'd say a minimum of 224 roller lobe would be the right choice here. 232 or 236 if you plan to go mid/upper 130's or faster.

And don't neglect the pushrods either. Buick v6 pushrods are relatively long (approaching 9"), and the usual 5/16" dia pushrods really flop around in there, especially the exhaust side. It's well worth it to take the time and effort to fit a much stronger pushrod, like say a 3/8" to 11/32" single taper from Manton Racing for example. Or even an 11/32" straight, if that's all you can fit through the head.

Needless to say, solid lifters makes a far better match at higher engine speeds too.

Just some thoughts.

TurboTR

 

[tonysmach]

I am building a stroker also but with GN1 heads (unported) and Champion stock ported intake. turbo will probably be a 6765. I am leaning towards a 215/220 cam. So for your build, seems like a 224/224 would be appropriate.

 

[bison]

What crank and rods?

 

[NCTURBOS]

You don't need to push 6500+rpm through the traps to run mid-9's @ 140+mph. You also don't need a very big cam either... Valvetrain control is important, IMO...


K.

 

[bison]

You don't need to push 6500+rpm through the traps to run mid-9's @ 140+mph. You also don't need a very big cam either... Valvetrain control is important, IMO...


K.

+1. converter selection is more important than cam selection.

 

[bluezone]

I'm running Scat H Beam Long Rods. As far as the Converter I have no clue yet... I will be running a Turbo 400 Trans... I will love to shift at around 6000 rpm or more... I wanna run Low 9's...

 

[quickt]

Removed 215/220 installed DLS 218 and picked up .6 and 8 mph. Went from 10.20 to 9.60s with nothing other than cam and spring change. I am sure Glad Tommy did not listen to "Cam does not matter" or "Converter is more important than the Cam"
Total combo matters. If you have an engine that makes power over a broad range you will still fly without the perfect converter. Cam your engine wrong and you will need to perfect converter to make it work.

 

[tonysmach]

Removed 215/220 installed DLS 218 and picked up .6 and 8 mph. Went from 10.20 to 9.60s with nothing other than cam and spring change. I am sure Glad Tommy did not listen to "Cam does not matter" or "Converter is more important than the Cam"
Total combo matters. If you have an engine that makes power over a broad range you will still fly without the perfect converter. Cam your engine wrong and you will need to perfect converter to make it work.

what heads and intake were you running? Was it a stroker?

 

[quickt]

what heads and intake were you running? Was it a stroker?

Tom is running 234" with old MA heads and converter slipage in the teens.

http://youtu.be/d9_HyJDGvio

Tom is in the Left Lane

 

[tom robison]

I am glad lonnie got me in the right direction, can't wait to see what it will do when we turn it up There is only a few people on this boardd I would listen to when it comes to my car and Lonnie is one of them.

 

[Nick Micale]

You don't need to push 6500+rpm through the traps to run mid-9's @ 140+mph.......

You are correct, he will need MORE than 6500 RPM to get mid-low 9's. :smile:

Please let me know how you have managed to do this, as the low 9 GN's I know personally are over 7000 RPM at that level and a lot more cam that has been suggested here.

I fully agree with Lonnie that the "total combo" is most important, especially at this level. This applies to the entire car, not just the drivetrain.

 

[Ed Valvo]

Converters do make a huge difference. I've got one in my car so efficient that "if" my car could take me to 140 mph at 6500 RPM, I'll still be on a 26" tire and 3.42 gears.

 

[quickt]

Converters do make a huge difference. I've got one in my car so efficient that "if" my car could take me to 140 mph at 6500 RPM, I'll still be on a 26" tire and 3.42 gears.

Ed I think you might be missing the Point. Of course converter is an important part of a combo. But most defiantly not the only part.

If a converter could fix everything and cam did not matter. Why would we ever remove a stock cam?

Toms car is just one example of a cam that makes power and produces RPM. He has a crap converter and still runs 140. With a good converter we believe he will go mid to upper 140s and low 9s. With his old 215/220 that everyone seems to think is a great piece. Best he could muster is 132mph with higher boost and more efficient converter. That cam just did not make the steam to get it done. The math is not there. Every car we have taken that cam out of has gone faster with something else.

Do your home work guys. Spend a few minutes on the Phone. If you are looking for the magic WIZ BANG cam here on the board you will be disappointed. During your research you will find that most combos need something different.

 

[SHADOWII]

I agree w/.......

Well, pretty much like any other engine, the cam needs to be sized for what you plan to do for optimal results. Do you plan to shift at 6000, or? As the car gets faster it wants to rpm more through the traps too. So gear ratio, cam, converter all play a roll here. A 28" tire with 3:42 rear makes a pretty nice combo for a fast street strip car, running about 6500'ish rpm into the high 130 to 140 mph or so trap speed range. A 210'ish hyd lifter cam being pushed like 6500 rpm through the traps? Way undersized for that for example IMO. And pushing it for hyd valvetrain to boot. Even a 218 hyd is pretty tiny here. When you get into the mid 10's zone and faster the engines really can wake up with better cams (and valvetrain). Assuming you plan to go at least 130 mph trap speed I'd say a minimum of 224 roller lobe would be the right choice here. 232 or 236 if you plan to go mid/upper 130's or faster.

And don't neglect the pushrods either. Buick v6 pushrods are relatively long (approaching 9"), and the usual 5/16" dia pushrods really flop around in there, especially the exhaust side. It's well worth it to take the time and effort to fit a much stronger pushrod, like say a 3/8" to 11/32" single taper from Manton Racing for example. Or even an 11/32" straight, if that's all you can fit through the head.

Needless to say, solid lifters makes a far better match at higher engine speeds too.

Just some thoughts.

TurboTR

If high rpms are going to be needed to get to your goal of low 9's, 224, 236, etc.
Ever hear an old adage that stated, "Too much knowledge can make one "mad"?
I believe the more knowledgeable board members have experienced it. they are all saying the same thing "Combo, Combo," w/Bison in support of Ncturbo's implying moderation of cam choice w/use of tighter(less slippage) convertor. And Nick supporting Lonnie's go bigger cam suggestion, while needing a better convertor for the "combo".
Now it's all clear as mud, right?:biggrin: Hey don't forget us little guys!:frown: And I need a new pump Lonnie.

 

[lazaris]

Ed I think you might be missing the Point. Of course converter is an important part of a combo. But most defiantly not the only part.

If a converter could fix everything and cam did not matter. Why would we ever remove a stock cam?

Toms car is just one example of a cam that makes power and produces RPM. He has a crap converter and still runs 140. With a good converter we believe he will go mid to upper 140s and low 9s. With his old 215/220 that everyone seems to think is a great piece. Best he could muster is 132mph with higher boost and more efficient converter. That cam just did not make the steam to get it done. The math is not there. Every car we have taken that cam out of has gone faster with something else.

Do your home work guys. Spend a few minutes on the Phone. If you are looking for the magic WIZ BANG cam here on the board you will be disappointed. During your research you will find that most combos need something different.

Some great advice right there.

 

[TurboDave]

You are correct, he will need MORE than 6500 RPM to get mid-low 9's. :smile:

Please let me know how you have managed to do this, as the low 9 GN's I know personally are over 7000 RPM at that level and a lot more cam that has been suggested here.

I fully agree with Lonnie that the "total combo" is most important, especially at this level. This applies to the entire car, not just the drivetrain.

Great points, and I think if I were building a combo like the OP's, and with his goals in mind, I would likely lean heavilly toward a 224 roller (solid?), and attempt to find someone that could build a perfect match converter for that. Of course this assumes he has the heads and intake that can support such a cam.

 

[quickt]

If high rpms are going to be needed to get to your goal of low 9's, 224, 236, etc.
Ever hear an old adage that stated, "Too much knowledge can make one "mad"?
I believe the more knowledgeable board members have experienced it. they are all saying the same thing "Combo, Combo," w/Bison in support of Ncturbo's implying moderation of cam choice w/use of tighter(less slippage) convertor. And Nick supporting Lonnie's go bigger cam suggestion, while needing a better convertor for the "combo".
Now it's all clear as mud, right?:biggrin: Hey don't forget us little guys!:frown: And I need a new pump Lonnie.

I am not saying bigger cam. I am saying the right cam for the job. If your goal is mid to low 9s your engine needs to make power. You can then tweek your converter to add the icing. I am not sure how to be much clearer.

Your in luck we done several pumps last week. Call me on tuesday.

 

[NCTURBOS]

You are correct, he will need MORE than 6500 RPM to get mid-low 9's. :smile:

Please let me know how you have managed to do this, as the low 9 GN's I know personally are over 7000 RPM at that level and a lot more cam that has been suggested here.

Going from the OP's very first post to this thread I wasn't picturing him wanting a low 9-sec. "street car". There are a very few limited number of stock block '109 true street cars running around in the low 9-sec. range. And yes, to get there it takes a complete combination, and I'm not just talking under the hood either...

My statement was more based on two true street cars that I have been involved with recently:

Car #1 runs 9.6x's at 139+mph with a DLS 210/210 duration hydraulic roller and a PTC non-lock converter. The car has never been twisted near as high as you mention.

Car #2 runs 9.4x's at 143+mph with a DLS 218/218 duration hydraulic roller and a PTC non-lock converter. This car as well has never seen close to the rpm range you mention.


K.