Cam selection help

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OldmanRick said:
Your right Justin, if a solid was used, with some of your heads:D, and that cam was in it's zone, it would be more stout then the one i was talking about. I'm just making the assumption that these courses are fairly short with slow corners. When John gets some runs in and we get some feedback, i may change my mind.
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I didnt mean to say it'd be better or worse, just my pick...Im no guru and i dont know everything, thats for sure.lol

I keep thinking that he should have more gear for this, why is that..:joker:

I would really like to know what the heads flow though...
If he put my stickers/logo on his car...id do work on the heads for free.
 
The 2nd gear only led me to believe it's a majority low speed, lower rpm course. I really don't know about this stuff either, but it's fun to talk about and learn something. That sticker/sponser deal sounds like a plan. :D
 
OldmanRick said:
Your right Justin, if a solid was used, with some of your heads:D, and that cam was in it's zone, it would be more stout then the one i was talking about. I'm just making the assumption that these courses are fairly short with slow corners. When John gets some runs in and we get some feedback, i may change my mind.

P.S. We may be splitting hairs here on the power. The Dillinger chassis parts may make the real difference.:thumbrig:
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Thanks Justin and Rick. I value your opinions a great deal. Not much of an engine guy here, but eager to learn. Rick for the time being I plan on running street tires and I'm sure the chassis can handle it, but when I go to sticky slicks then I will be installing a cage and tying everything together. You know how it goes, break something and make it stronger. Not talking about my parts of course. LOL
 
I think if gear braking and stock convertor are needed, I'd go with a steeper rear axle ratio. Somethign like a 4.10:1. I haven't raced SOLO but a buddy's father was a tech inspector for SCCA for years and in the past had some insight. You are on and off the power a lot and almost never in high rpms. You're better having some gear not only to pull harder low down but also to maintain the rpm range in middle gears.
I'd also go with a solid flat tappet stictly for torque and midrange. Either the 270S or XS268S Comps.
The FL lobes are a great lobe and I've used them a few times in stroked applications where you have the head/port for it. But in terms of low and midrange with a basically stock port, weak exhaust port, and long rod - I think the Max Area low lift lobes might be a better choice. The cam can be ground with less overlap and even though they are a faster rate of lift, they are a little "later" in terms of when they reach max lift. That puts the piston in a better spot to pull harder during the max lift. Just a thought anyway...
 
moper said:
I think if gear braking and stock convertor are needed, I'd go with a steeper rear axle ratio. Somethign like a 4.10:1. I haven't raced SOLO but a buddy's father was a tech inspector for SCCA for years and in the past had some insight. You are on and off the power a lot and almost never in high rpms. You're better having some gear not only to pull harder low down but also to maintain the rpm range in middle gears.
I'd also go with a solid flat tappet stictly for torque and midrange. Either the 270S or XS268S Comps.
The FL lobes are a great lobe and I've used them a few times in stroked applications where you have the head/port for it. But in terms of low and midrange with a basically stock port, weak exhaust port, and long rod - I think the Max Area low lift lobes might be a better choice. The cam can be ground with less overlap and even though they are a faster rate of lift, they are a little "later" in terms of when they reach max lift. That puts the piston in a better spot to pull harder during the max lift. Just a thought anyway...
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Wow thanks Moper, actually the 270S calls for the same valve springs that I have already on the heads. They have been machined for these springs already. It may be an option.
 
flowed an intake port today.
cfm @28 4'' bore w/clay radius
.100-67
.200-124
.300-175.5
.400-222
.450-225
.500-217-216\/
Definite shape issue
The peak about hits 227-230cfm around the .470 lift...but it's too shaky/turbulent to be able to hold on. the ports are polished to hell.

gonna work the turn some and then just rough the rest of it a hair and retest.
 
1wild&crazyguy said:
flowed an intake port today.
cfm @28 4'' bore w/clay radius
.100-67
.200-124
.300-175.5
.400-222
.450-225
.500-217-216\/
Definite shape issue
The peak about hits 227-230cfm around the .470 lift...but it's too shaky/turbulent to be able to hold on. the ports are polished to hell.

gonna work the turn some and then just rough the rest of it a hair and retest.
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Yikes Justin. Those are pretty sad numbers. Why does it fall off after .400"? I am anxious to see what you can do.
 
Badart said:
Yikes Justin. Those are pretty sad numbers. Why does it fall off after .400"? I am anxious to see what you can do.
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i dont see many heads doing better without the roof kink taken out, also the bowl is perfectly round and mirror finished and the short turn isnt laid back at all really besides a hair of straightening near the straight wall portion.

were these heads originally 1.88 versions?
that would explain it right there, another thing people need to know is starting out as 1.88 heads there is way more work than one would think to get them just to 230cfm just cutting to 2.02. this is a good example why all the rag mags report such **** numbers...cause they start out as 1.88 and just cut the 2.02 and only blend or round the transition to the throat, if mags would flow factory 2.02 x or j heads, the numbers floating around as hear say would be 228-230 STOCK and not 190's 0r 205
 
i laid it back at the turn, and worked the straight wall turn, also a lil bit of the farside bowl but only on the straight wall side, pocketed it more, left the rest alone.
I dont like the valve job, there is micro lip at the seat, i cant fk with it or it will another valve job...which is what i do to get that .300 number into shape.

new numbers after 20 min of work

cfm @28 4'' bore w/clay radius

.100-75.8=76
.200-132.7=133
.300-187.2
.400-232.6=233
.450-246.7=247
.500-249.1
.550-238.8=239

you just round them to the nearest, but i like giving exactly what i read number wise.

conclusion...way better now, and real good for not even touching the roof kink.
 
I wonder if a set of rhoads lifters would allow your cam to work, reportedly take out 10-12 degrees of duration?? just a thought
 
Start a thread,with your combo listed.In certain situations ,they work.Thay way,we can help you best.
 
Tomorrow ill do more and see about 260's, if its ok with badart..lol
I can simply take the roof kink out, and/or work the straight wall/short turn more.
All about how far he wants to go...

to the guy asking about a cam and these toads lifters...start your own thread, and btw..im sick of hearing about bandaid lifters.lol... old hat ****. Just run a dual plane and/or some real gear and learn how to tune and set valve lash on a solid
 
1wild&crazyguy said:
Tomorrow ill do more and see about 260's, if its ok with badart..lol
I can simply take the roof kink out, and/or work the straight wall/short turn more.
All about how far he wants to go...

to the guy asking about a cam and these toads lifters...start your own thread, and btw..im sick of hearing about bandaid lifters.lol... old hat ****. Just run a dual plane and/or some real gear and learn how to tune and set valve lash on a solid
Click to expand...

Wow thanks Justin. Flowing 260s sounds good to me, but I'm an idiot when it comes to to head flow and cam shafts. I plan on running quite a bit more gear than I originally posted, well at least have a couple of different chunks to swap out at the track if need be. I plan on running a Holley 750 with vacuum secondaries (are the vacuum secondaries going to be an issue?) I have messed with holleys quite a bit, swapping springs, jets, pv, squirters and what not. Once the car is together and running decent I plan on scheduling some chassis dyno time and finish up the tuning there. I figure that will be money well spent.

The car is coming right along. Car is gutted and engine and trans is coming out this weekend and will be installing the cage and doing a little more metal repair. Building a sub floor in the trunk and installing the fuel cell and battery in the trunk
 
"that would explain it right there, another thing people need to know is starting out as 1.88 heads there is way more work than one would think to get them just to 230cfm just cutting to 2.02."

x2 - as the rest of the posts say...
Normally when I replace the valves I bring the seats up and out - so I go with 2.02 if they are 1.88s, or 2.05s if they were 2.02s. I will also:
- Do a 5 angle valve job - this provides the main bowl hogging and also unshrouds the chamber
- Rework the bowl with minor attention to the guide boss - I don't eliminate it - just reshape a little.
- Round and lay back the SSR slightly.
- Gasket match the opening and blend in past the pinch, enlarging the pinch area. I do not touch the floor
- I do not polish - in some spots it's left at the carbide burr finish others I'll hit with a coarse sand roll.
 
moper said:
"that would explain it right there, another thing people need to know is starting out as 1.88 heads there is way more work than one would think to get them just to 230cfm just cutting to 2.02."

x2 - as the rest of the posts say...
Normally when I replace the valves I bring the seats up and out - so I go with 2.02 if they are 1.88s, or 2.05s if they were 2.02s. I will also:
- Do a 5 angle valve job - this provides the main bowl hogging and also unshrouds the chamber
- Rework the bowl with minor attention to the guide boss - I don't eliminate it - just reshape a little.
- Round and lay back the SSR slightly.
- Gasket match the opening and blend in past the pinch, enlarging the pinch area. I do not touch the floor
- I do not polish - in some spots it's left at the carbide burr finish others I'll hit with coarse sand roll.
Click to expand...

In regards to starting with 1.88 heads
Yep, you can get 240 easier either staying with the 1.88 or 1.94 than 2.02 'though that's about it' UNLESS you do like you mentioned with the five angle serdi cutter as to open the throat up a bunch, let alone the turn needs a lil less laying back cause it doesnt start out as steap and over hanging as it get after a stone age vj. I will say this though...if u really know shape, you can still make quicker work of it than a novice.
I leave it all rough, see my lil trick is to use a dulled beat up cutter to finish with and leave an almost as cast finish ;)...another is a coarse 2" flat stone roller, that really roughs it for slowing it down..
Now if u have factory 2.02 heads....u are ahead , the factory actually does a good job opening them up, they already do 225-230 cfm...and as a side note, that's when u have to ask why u would pay1400 dollars to run ootb aluminum heads that only go 240's. Only worth it if u port them! LOL
 
Exh numbers for Badarts heads as i got them.
w/1.60
-lift--cfm
.200-73
.300-123
.400-146
.500-154
.600-160

After opening the bowl up, smoothing the roof kink and re shaping the short turn.
-lift--cfm
.200-92
.300-135
.400-155
.500-171.3
.550-175
.600-185
 
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