multi port fuel injected 363 c.i. sbc cam help!

[underpressure]

Hi Folks, this is the parts list for my current build.

350 chevy 4 bolt block bored to 4.030
scat ultralight crank stroked to 3.562 producing 363 c.i.
crower titanium rods, length 5.950
mahle flat top pistons w/ 5cc valve reliefs
afr 195 eliminator heads 65cc pocket w/ 2.05 i.v. 1.65 e.v.
crane 1.5 roller rockers. fel-pro head gaskets .041 thick
compression comes in right @ 10.46
the headers are ceramic coated block hugger 2 1/2'' & 1 5/8''
fuel supply is a edelbrock pro-flo 2 victor jr style manifold,
the electronics i'm using is the fast e-z efi multi port with 35lb injectors.
I'm planning on bolting this into a 3100lb 66' stingray coupe,
the car has a richmond 6 speed close ratio road race trans with a 2.77 1st and .62 overdrive. rear diff is 3.73 with a 25'' tall tire.
Opperating range 1800-6300 rpm.

Now we get around to the camshaft......any body got a bottle!
I should first outline the usage for the car, basically it's going to be for weekend trips and an occasional industrial parking lot flogging! I'm also looking to get some kind of mileage out of it, and make good power, so i'm not trying to achieve max dyno numbers, just want good power and instant rev's. still torn between a solid roller and a "short travel" hydraulic roller, just to keep the oil in the pan in high rpm's. It's similar to the 96' Lt4 but with more c.i., superior electronics, more injector, and better heads.

Well Folks...that pretty much sums it up! So if there's anybody that
would like to trade this for a new LS7?....oh sure! or can help me with some cam knowledge i surely would appreciate it! Thanks'.
Underpressure.

 

[grumpyvette]

lets look over the list and I will post a few links and comments

Hi Folks, this is the parts list for my current build.

350 chevy 4 bolt block bored to 4.030
scat ultralight crank stroked to 3.562 producing 363 c.i.
both the reasonably short stroke and the light titanium rods give you the potential to spin about 7300rpm, but both the heads cross sectional area and the need to get decent low rpm torque and street use makes that basically a non-issue, as your not going to be using a cam that gives you that full rpm potential, every component is a compromise in several areas, in this case your going to want to be a bit conservative because its going to be used far more on the street
viewtopic.php?f=53&t=343&p=16772&hilit=redline#p16772

crower titanium rods, length 5.950

mahle flat top pistons w/ 5cc valve reliefs
afr 195 eliminator heads 65cc pocket w/ 2.05 i.v. 1.65 e.v.
your choice in heads will make excellent mid rpm torque but its likely to be a bit restrictive over about 6000rpm, if max peak hp is the goal.
http://www.rbracing-rsr.com/runnertorquecalc.html
viewtopic.php?f=52&t=322
crane 1.5 roller rockers. fel-pro head gaskets .041 thick
compression comes in right @ 10.46

I get closer to 10:1 after doing the math which is better in this case for a street combo
http://www.rbracing-rsr.com/compstaticcalc.html
viewtopic.php?f=52&t=727
viewtopic.php?f=52&t=1070
http://www.crower.com/valve-timing-chart/
http://www.kb-silvolite.com/calc.php?action=comp2

the headers are ceramic coated block hugger 2 1/2'' & 1 5/8''
not knowing your true header primary length makes the calculations a bit less precise but its certainly not something I can,t make an educated guess at
http://www.pontiacracing.net/js_header_length1.htm
viewtopic.php?f=56&t=185

fuel supply is a edelbrock pro-flo 2 victor jr style manifold,
the electronics i'm using is the fast e-z efi multi port with 35lb injectors.

35 lb injectors will more than likely limit you to just under 500hp
viewtopic.php?f=55&t=1200

I'm planning on bolting this into a 3100lb 66' stingray coupe,
the car has a richmond 6 speed close ratio road race trans with a 2.77 1st and .62 overdrive. rear diff is 3.73 with a 25'' tall tire.
Opperating range 1800-6300 rpm.

Now we get around to the camshaft......any body got a bottle!
I should first outline the usage for the car, basically it's going to be for weekend trips and an occasional industrial parking lot flogging! I'm also looking to get some kind of mileage out of it, and make good power, so i'm not trying to achieve max dyno numbers, just want good power and instant rev's. still torn between a solid roller and a "short travel" hydraulic roller, just to keep the oil in the pan in high rpm's. It's similar to the 96' Lt4 but with more c.i., superior electronics, more injector, and better heads.

Well Folks...that pretty much sums it up! So if there's anybody that
would like to trade this for a new LS7?....oh sure! or can help me with some cam knowledge i surely would appreciate it! Thanks'.
Underpressure.

personally after looking over what your trying to do and the parts your using Id go with this cam, its true that there are cams that would give a bit more peak HP but this should match your goals rather well, ID install it straight up, (4 degrees retarded from DOT-to_dot indexed, which should get your dynamic compression in a reasonable range for high test gas octane levels if you use a 160F T stat and a good cooling system, and keep the fuel/air ratio in the 12.8-13:1 range for max torque

COMMENTS? QUESTIONS?
is this a great deal different than what most cam techs have suggested?

 

[Indycars]

Hi Folks, this is the parts list for my current build.

350 chevy 4 bolt block bored to 4.030
scat ultralight crank stroked to 3.562 producing 363 c.i.
crower titanium rods, length 5.950
mahle flat top pistons w/ 5cc valve reliefs
afr 195 eliminator heads 65cc pocket w/ 2.05 i.v. 1.65 e.v.
crane 1.5 roller rockers. fel-pro head gaskets .041 thick
compression comes in right @ 10.46
the headers are ceramic coated block hugger 2 1/2'' & 1 5/8''
fuel supply is a edelbrock pro-flo 2 victor jr style manifold,
the electronics i'm using is the fast e-z efi multi port with 35lb injectors.
I'm planning on bolting this into a 3100lb 66' stingray coupe,
the car has a richmond 6 speed close ratio road race trans with a 2.77 1st and .62 overdrive. rear diff is 3.73 with a 25'' tall tire.
Opperating range 1800-6300 rpm.

Underpressure.

What's your quench height going to be with that rotating assembly?

What's the part number for those Mahle pistons?

 

[grumpyvette]

hes said the rods are 5.95" length and hes using pistons designed for 6" rods, now I assumed a few things during the calculations, but I don,t think the results will be that far from reality, so with a 3.560: stroke and a nominal 9.023 deck ypu get 9.023-1.78"(stroke) -minus 5.95" rods =1.302-- plus .041(gasket thickness) or 1.343 between piston pin and cylinder head
and a 1.250 compression height for a .090 or so quench (not great but many factory engines run similar clearances
http://www.jegs.com/i/Mahle/644/SBC250030F05/10002/-1

you might be shocked at all the info in links and sub-links

viewtopic.php?f=52&t=4081&p=11104#p11104

viewtopic.php?f=50&t=6853

 

[Indycars]

hes said the rods are 5.95" length and hes using pistons designed for 6" rods, now I assumed a few things during the calculations, but I don,t think the results will be that far from reality, so with a 3.560: stroke and a nominal 9.023 deck ypu get 9.023-1.78"(stroke) -minus 5.95" rods =1.302-- plus .041(gasket thickness) or 1.343 between piston pin and cylinder head
and a 1.250 compression height for a .090 or so quench (not great but many factory engines run similar clearances
http://www.jegs.com/i/Mahle/644/SBC250030F05/10002/-1

If he is spending the kind of money it takes to buy the parts listed, he shouldn't accept a .090" quench.

If he is getting 10.46 static CR, then his quench distance has to be near .041" and a deck clearance of zero.

Engine 1 has a quench of .090" (.049 + .041)
Engine 2 has a quench of .041" (0.0 + .041)

 

[underpressure]

Thank you for the response grumpyvette and indycars, "great" technical info! you guy's really know your doodoo! grumpvette was right on the money with the piston that i'm using, it is mahle part #sbc 250030f05 intended for a 6" rod. I made up the .050 short on the rod with the additional stroke on the crank.
Funny story on those rod's, i went to a swap meet to find something good and affordable. When i spotted those titanium's sitting under a table. I asked the guy what they were for and he said he did'nt know, he found them in the trunk of a car that they towed into their yard!...well...what do you want for em'?....$50.00,
so i offered him $40.00....true story!
I sent them to crower for inspection, they gave them a clean bill of health and sent them back!
I mocked-it up with a piston in each corner and had .023 on the deck, so i had it milled to exact "0" deck. Now... using a .041 gasket i may be running too close for comfort, also looking at the compression figures, 10.46 is right on the edge of pump gas compatibility. It might be a good idea to throw a thicker head gasket in there and serve a dual purpose.
In respect to the cam company's, i completely agree with you, they go from one end of the scale to the other! depending on who you talk to! Those cam spec's you crunched out for me look real good, although i may have to change it if i drop the compression, what do you think?
Thanks.... Underpressure

 

[Indycars]

Thank you for the response grumpyvette and indycars, "great" technical info! you guy's really know your doodoo! grumpvette was right on the money with the piston that i'm using, it is mahle part #sbc 250030f05 intended for a 6" rod. I made up the .050 short on the rod with the additional stroke on the crank.
Funny story on those rod's, i went to a swap meet to find something good and affordable. When i spotted those titanium's sitting under a table. I asked the guy what they were for and he said he did'nt know, he found them in the trunk of a car that they towed into their yard!...well...what do you want for em'?....$50.00,
so i offered him $40.00....true story!
I sent them to crower for inspection, they gave them a clean bill of health and sent them back!
I mocked-it up with a piston in each corner and had .023 on the deck, so i had it milled to exact "0" deck. Now... using a .041 gasket i may be running too close for comfort, also looking at the compression figures, 10.46 is right on the edge of pump gas compatibility. It might be a good idea to throw a thicker head gasket in there and serve a dual purpose.
In respect to the cam company's, i completely agree with you, they go from one end of the scale to the other! depending on who you talk to! Those cam spec's you crunched out for me look real good, although i may have to change it if i drop the compression, what do you think?
Thanks.... Underpressure

Don't you feel just a little bit guilty talking him down, just to save another $10.

Are you going to replace the rod bolts or did Crower inspect them also? Just curious.....what did Crower charge for the inspection?


I don't know about Titanium, but if they are the same as Steel rod, then.......
I would NOT think .041" is too close, but you could go to a thicker gasket by .010" if you would feel more comfortable. This would also lower your static CR to 10.19 from 10.44. You really don't need a lower compression when considering pump gas and possible detonation. Your dynamic CR is plenty low at 7.32 on engine #2. You can run a DCR of 8.0 to 8.25 and be pretty safe, but Grumpy would have the best advice on the DCR.

 

[grumpyvette]

Id be more inclined to swap to a different FORGED piston than to add more duration to the cam
a FORGED piston with a 12cc-14cc dish top would certainly make the compression ration more pump gas friendly, as would a bit of machine work on the combustion chambers to both smooth the surface and increase the combustion chamber volume, so you might want to as AIR FLOW RESEARCH about the cost and availability of RE-machining the heads to the larger 75cc combustion chamber size they offer , or selling the current heads and getting the newer larger combustion chamber heads, which might be cheaper to do or even swapping heads to a different brand

http://www.airflowresearch.com/index.php?cPath=24_29

EXAMPLE

http://www.profilerperformance.com/raci ... -23-degree

http://www.airflowresearch.com/index.php?cPath=24_33

http://www.brodix.com/heads/ik.php

http://www.summitracing.com/search/?key ... 7%20&dds=1

 

[Indycars]

Id be more inclined to swap to a different FORGED piston than to add more duration to the cam
a FORGED piston with a 12cc-14cc dish top would certainly make the compression ration more pump gas friendly, as would a bit of machine work on the combustion chambers to both smooth the surface and increase the combustion chamber volume, so you might want to ask AIR FLOW RESEARCH about the cost and availability of RE-machining the heads to the larger 75cc combustion chamber size they offer , or selling the current heads and getting the newer larger combustion chamber heads, which might be cheaper to do or even swapping heads to a different brand

Do you really think there might be a problem with detonation on pump gas with a DCR in the 7.15 to 7.32 range???

Everything I've read on this forum is in the 8.0 DCR range. Please explain what's different in this situation.

 

[underpressure]

Thank you for the response grumpyvette and indycars, "great" technical info! you guy's really know your doodoo! grumpvette was right on the money with the piston that i'm using, it is mahle part #sbc 250030f05 intended for a 6" rod. I made up the .050 short on the rod with the additional stroke on the crank.
Funny story on those rod's, i went to a swap meet to find something good and affordable. When i spotted those titanium's sitting under a table. I asked the guy what they were for and he said he did'nt know, he found them in the trunk of a car that they towed into their yard!...well...what do you want for em'?....$50.00,
so i offered him $40.00....true story!
I sent them to crower for inspection, they gave them a clean bill of health and sent them back!
I mocked-it up with a piston in each corner and had .023 on the deck, so i had it milled to exact "0" deck. Now... using a .041 gasket i may be running too close for comfort, also looking at the compression figures, 10.46 is right on the edge of pump gas compatibility. It might be a good idea to throw a thicker head gasket in there and serve a dual purpose.
In respect to the cam company's, i completely agree with you, they go from one end of the scale to the other! depending on who you talk to! Those cam spec's you crunched out for me look real good, although i may have to change it if i drop the compression, what do you think?
Thanks.... Underpressure

Don't you feel just a little bit guilty talking him down, just to save another $10.

Naaa!....it cost me 10 buck's to get in!

Are you going to replace the rod bolts or did Crower inspect them also? Just curious.....what did Crower charge for the inspection?

Well...what they thought was the best thing to do was to strip them, and run them through a complete inspection just to insure they were in good condition, after that they re-plated the large end. Evidently titanium doesn't get along with itself or other metals, they also replaced the bolts. Price...$500.
Still....not bad, Total Cost....$550. including my ten bucks to get in!

I don't know about Titanium, but if they are the same as Steel rod, then.......

Dave Crower told me to treat them just like steel rods.

I would NOT think .041" is too close, but you could go to a thicker gasket by .010" if you would feel more comfortable. This would also lower your static CR to 10.19 from 10.44. You really don't need a lower compression when considering pump gas and possible detonation. Your dynamic CR is plenty low at 7.32 on engine #2. You can run a DCR of 8.0 to 8.25 and be pretty safe, but Grumpy would have the best advice on the DCR.

 

[grumpyvette]

your making me think that maybe my dcr calcs are wrong, heres what I used, the cam card indicates that the intake closes at 44 degrees past TDC, (@ .050 lift) so you add 15 degrees to that to find valve close point, hes got 10.4:1 static compression, ......it won,t be the first or last time IM wrong!
yes the car will most likely run just fine on high octane gas with few problems, but it will be close to getting into detonation if the coolant temps run hot or you get bad fuel if my calculation figures are correct.
and just to be clear, Ive built and run engines with that high of calculated DCR in the past and most of them ran great, but a few eventually did develop problems over time, so its not like its going to explode on start-up its just that youll need to always run high test and watch the coolant temps and ignition advance curve
http://www.kb-silvolite.com/test/calc.php?action=comp

 

[Indycars]

your making me think that maybe my dcr calcs are wrong, heres what I used, the cam card indicates that the intake closes at 44 degrees past TDC, (@ .050 lift) so you add 15 degrees to that to find valve close point, hes got 10.4:1 static compression, ......it won,t be the first or last time IM wrong!

No need to estimate the IVC angle, it says right in the specs. That would be the difference between our calculations, you used 60 and I used 79.

 

[grumpyvette]

yes your correct, I missed that,and yes thanks for pointing out the simple math error, he should be fine!
THANK YOU!
ITs always nice to have someone point out the potential errors BEFORE the build gets into the parts purchase stage
I went back and checked all the other math and that was the only real screw up so the rest is valid

were not here to do much anything other than help each other improve our knowledge , and avoid errors and no ones perfect, but we all can and do provide a great deal of useful info and experience.

 

[grumpyvette]

underpressure??

well what are YOU thinking here!
what if anything have you decided?
what did others suggest and whats your take on all this?

 

[underpressure]

Hi grumpyvette, well.....i'm thinking i have too much compression in this thing, and i should probably reel it in a little bit. So it look's like i have a couple of option's, i could use a cam that's cut on a 113 lsa and higher duration numbers to bleed off some compression, i'd lose some low end performance and possibly be a little choppier than i'd like it to be. Or i could pull the heads off this puppy and put the .051 thick gasket's in and drop it down around 10.2.
The crane cam that you spec'd-out looks great!, and probably would get descent fuel mileage! Leanin' more towards mileage about now, we are already looking @ $5.00 a gallon out here in ca.
Early on in this build i talked to every cam company known to exist!
I ended up buying a cam from isky, they spec'd it out for the fuel injection that i'm installing on this engine.
cam spec's are 286/290, 241/245@ .050 lift is .558/.558
intake opens @ 33 before tdc and closes @ 73 after bdc.
exhaust opens @ 75 before bdc and closes @ 35 after tdc.
cam is cut on a 110 lsa and lift numbers are for 1.5 rockers.
Now.... knowing a little bit more about efi and the vacume requirements needed to support it, i dont' believe this cam is going to work very well! Is it a $427. and 35 cent paper weight?
What do you think?....Thanks....underpressure.!

 

[grumpyvette]

that cam sounds like its designed for making near max power levels with far less thought going to its drive-ability, and nearly zero to getting good mileage, now remember probably 80% of the guys buying cams want to maximize peak power levels.
I eventually tried 14 cams in 3 different 383 engines in my corvette before I found what for me was the best compromise between horsepower and drive-ability

we all need top make compromises in selecting parts, because I spend 99% of my time driving on the street,theres no question that three cams were exceptional, all were hydraulic roller cams
crowers 00471 made excellent power over the mid and upper rpms and acceptable drive-ability and it would make a great choice in a lighter weight car

cranes 119681 made excellent upper rpm power and acceptable the mid range but acceptable drive-ability was not there

cranes 119661 made excellent mid rpm power and acceptable upper rpms power and acceptable drive-ability so thats what I eventually selected, because I had a nitrous system on the car for race use.

but that was in my combo , and what I might call acceptable may not match your idea and its not your combo or car and there were significant differences
viewtopic.php?f=32&t=430

 

[underpressure]

Hi grumpyvette, Thanks' again for the info! Looking over the numbers on those cams, and seeing the results that they delivered, you can clearly see how duration dictates how the engine is going to perform at different rpm's. If a 110 lsa is not going to hurt the fuel mileage, and overall performance with the efi, i think i'm going to send the isky off to crower and have it ground to that 471 spec.
What do you think?...underpressure.

 

[grumpyvette]

Id keep the isky cam for future use or trade value and just buy the crower 00471, by regrinding it youll lose the isky cams use and value and by the time its reground and shipped both ways you won,t save that much in total cost, plus your very likely to have a very small base circle, Id just store, or sell the isky and buy the crower.

are you aware crower has cams on sale frequently in the clearance area, you might find one thats very similar, its worth looking thru, inventory changes frequently

http://www.crower.com/clearance/camshafts.html/

 

[Indycars]

Hi grumpyvette, well.....i'm thinking i have too much compression in this thing, and i should probably reel it in a little bit.

If you are worried about the compression ratio, changing the camshaft will have not effect the static compression ratio. But it will change your Dynamic CR.

The Crower cams specs above don't directly state the IVC angle, but it can be calculated.

IVC = Lobe Separation Angle - (Adv or Retard) + (Intake Duration / 2) - 180

IVC = 110 - (+4) + (286/2) - 180
IVC = 106 + 143 - 180
IVC = 69 Degrees ABDC

Below are the three camshafts that Grumpy mentioned directly above.



Just wanted to make sure you were considering the whole picture, I will get out of the way now.

 

[grumpyvette]

as always, thats VERY IMPRESSIVE! indycars, thanks for posting