493 Stroker Cam and Intake Selection

[nstyle73]

493, so 4.15 stroke, .030 over. I have heard the single plane thing about FI, especially the Holley, but I have seen a couple builds using the FITech units with dual planes while achieving good results. I also have several people telling me not to run FI, but that is a definite at this point. Anyway, I spoke with Hughes about porting the RPM and they are much more reasonable than I expected after seeing their website and checking the Wilson website. About a week-ish turn around right now. I also found a post by IQ52, who I have gained respect for over the years of his non-pompous posts concerning engine building, involving a very similar combination's dyne numbers that I would be delighted to replicate. Unfortunately I can't find the thread now, but it was a 10.3:1 stroker with aluminum heads with both a Torker II and Ported RPM compared. He listed the cam as well and the RPM made peak torque around 3600, something like 640 ftlbs and peak HP near 6K in that same 625-640 range. The Torker (albeit maybe not the best single plane, but a streetable one) was shifted much higher with not a significant gain.

 

[Bobo]

 

[nstyle73]

Guess I should have used the search button before posting this thread to begin with . This post is from IQ52 to a different member in a previous thread (the 40230733 is a mechanical roller 249/255 @0.050, .585/600" @0.050):

"I think you would find either cam exciting in your car. Here is a 496 with RPM heads flowing 306cfm @ .600". We were using a Torker II single plane, a 2" spacer, Q950 and running 10.3:1 on 91 octane. Oh, and the 40230733 camshaft. 2nd column is the same engine with a ported RPM dual plane intake and no spacer.

RPM..........TQ/HP............Ported Edelbrock RPM intake

3000..........530/303.....................540/309
3200..........554/337.....................570/347
3400..........591/383.....................614/398
3600..........612/419.....................639/438
3800..........613/443.....................638/462
4000..........615/468.....................639/486
4200..........613/490.....................628/502
4400..........616/516.....................611/512
4600..........617/540.....................607/531
4800..........614/561.....................607/554
5000..........623/593.....................609/579
5200..........620/614.....................614/608
5400..........614/631.....................597/614
5600..........602/642.....................590/629
5800..........584/645.....................578/638
5900..........582/654.....................570/640
6000..........564/645.....................550/628
6100..........552/641.....................533/619
6200..........549/649.....................539/631
6300............na/na.......................518/621

The owner runs it on the street with the Torker II, 3.23 gears and a 4-spd. Loves it."

 

[nstyle73]

The TF240 heads are rated by TF at 326cfm and 253cfm at 0.600" for reference

 

[wyrmrider]

The TF240 heads are rated by TF at 326cfm and 253cfm at 0.600" for reference

On the Lunati I think I'd run some 1.6 rockers on the intake- get it higher than the exhaust- what were they thinking?
I'd run the Edelbrock on the street I do not like to give up 25 foot lbs in the mid range
I think I'd start with those head flows and match the cam to them
I like inverse flank rollers- that would allow me to drop the Intake to around 240 with a similar lift curve where it counts and more lift with the rockers- but that's TBD
do you have a complete flow list for those heads - how do they flow at lower lifts- do they get with the program early?

 

[nstyle73]

Jones Cams came back with this:
242/245 @.050"
.375"/.370" Lobe Lift
114 LSA

Both Comp and Jones suggested the 1.6 rockers. That puts this cam right around 0.600"/0.592, or 0.562/0.555" with 1.5 for comparison to the other cams. The 114LSA was surprising, doesn't this give up some of the bottom end torque? but a better idle vacuum? 112 seems to be about as wide as most of the box manufacturers offer so that is a plus, Crane being the other one I have seen. Cost was equivalent there. Most modern performance engines run a wide LSA and its beneficial to fuel injection with its minimal overlap.

 

[451Mopar]

Jones Cams came back with this:
242/245 @.050"
.375"/.370" Lobe Lift
114 LSA

Both Comp and Jones suggested the 1.6 rockers. That puts this cam right around 0.600"/0.592, or 0.562/0.555" with 1.5 for comparison to the other cams. The 114LSA was surprising, doesn't this give up some of the bottom end torque? but a better idle vacuum? 112 seems to be about as wide as most of the box manufacturers offer so that is a plus, Crane being the other one I have seen. Cost was equivalent there. Most modern performance engines run a wide LSA and its beneficial to fuel injection with its minimal overlap.

The cam spec numbers are just a way of specifying the intake and exhaust open and close points.
That Jones cam looks decent for this. The larger intake duration will help reduce dynamic compression for pump gas with the higher compression ratio. The wider LSA reduces overlap which is easier for the computer to read the map sensor. It also spreads the torque curve out over a wider range, but normally the torque curve is less peaky.
The Jones cam LSA should not hurt bottom end torque, the installed position (intake centerline) would make a bigger difference in the bottom of the torque curve. You may be down a little bit of torque in the mid/upper RPM range?
What is the recommended Installed Intake Centerline? +2 or +4 (112 or 110?)
FWIW, the Jones 242/[email protected]" with 114 LSA, overlap = 15.5 degrees using the 0.050" duration numbers. The Comp 236/[email protected]" with 110 LSA has 19 degrees of overlap.

 

[nstyle73]

Several things about that cam pique my interest, including the LSA and the intake lift being greater than the exhaust. Obviously the actual cam profile is proprietary so those standard numbers are not the entire story but when really looking at the cam specs for Mopar big blocks, most "box" cams are narrower LSA, I assume to get that idle sound, and the exhaust lift being greater than the intake. I am still waiting to hear back from Dwayne Porter and Howards Cams. I have learned a lot about cams if nothing else and about the differences of a Mopar vs Chevy. A friend has a 396 Chevy with a large Isky cam and little to no vacuum and he showed me the specs, 280/[email protected]" and I forget the lift, but they were not surprising numbers compared to the duration.

 

[451Mopar]

I would not be concerned about the exhaust lift. Most likely a exhaust specific lobe profile?
I think many of the cams we normally see are using a similar lobe profile for both the intake and exhaust, and with the exhaust having more duration, it usually has more lift but really dont need the extra lift because the exhaust is under higher pressure at max lift.
The exhaust lobe needs to open against both the valve spring pressure and the pressure in the cylinder. A 1.82" head exhaust valve has an area of 2.6", so the lobe/lifter/pushrod are opening against 2.6 x cylinder pressure + valve spring seat pressure. This is why some run a lower ratio rocker arm on the exhaust.

 

[62 Dart Convertible]

The 114LSA was surprising, doesn't this give up some of the bottom end torque? but a better idle vacuum? 112 seems to be about as wide as most of the box manufacturers offer so that is a plus, Crane being the other one I have seen.

Lower LSA = more overlap = less vacuum and bottom end.

 

[nstyle73]

http://www.hotrod.com/articles/camshaft-shootout-lobe-separation-angle-tested-explained. The rest of the short block has Ross flat top pistons, Scat crank, Scat H beam rods, Melling HV63 oil pump and soon to be a Jones Cam. Up top with the TF240's are Crane 1.6 Roller Rockers. I spoke with Jones Cams today and ironed out the few questions I had. The cam requires a Mellanized distributor drive gear ($65 ish) which is apparently common for hydraulic rollers from billet steel, but should work with the valve springs in the TF240's. We discussed the retrofit roller lifters but he did not currently have a recommendation as he said many of the common names are selling the same Morel lifter under their brand name, of which there is a street version and a race version (5W oil), no intermediate performance version. He was not sure about Comp as they apparently changed manufacturers in the last year or so. Crower, Isky, TF, Crane, Howards and Comp offer lifters, some of these are high end offerings, but if the other ones are all from the same manufacturer...... Howards and Lunati physically appear to be Morel, based on their website pictures. TF, Edelbrock and Comp appear physically the same. Isky and Crower are both higher end offerings, price wise.

 

[451Mopar]

http://www.hotrod.com/articles/camshaft-shootout-lobe-separation-angle-tested-explained.

That article could have been so much better. If you read farther down they show that the cams intake centerline was changed to the LSA number, which explains why they had different cranking compressions, and also why the wide LSA cam had less low end than the narrow LSA cam. If they wanted to show the changes based only on LSA, they should have maintained the same intake install centerline.

 

[383man]

Myself I run the Indy dual plane intake on my 493 and I like it. Its like the RPM intake but has bigger ports and runners. Using an 850 DP mine has run 10.70's through the full exh on pump and driven to the track. On my cam I went with a custom flat tappet from Dwayne Porter and it is 264 & 270 @ .050 WITH .585 & .592 LIFT AND A 110 LSA. I have it on a 106 ICL. Ron

 

[nstyle73]

Sounds like a stout engine, hard to argue with those times. That is a good point on the Indy intake, I may check into that.

 

[nstyle73]

Looks like that manifold might be too tall for my Ramcharger, one place says it is 0.25" shorter than the RPM and Hughes Engines Website shows it being 6" tall at the front edge. Guess I need to break out a ruler.

 

[m79ded]

The TF240 heads are rated by TF at 326cfm and 253cfm at 0.600" for reference

Tested 2 sets of TF240's and they were very close to their advertised numbers. Came in at 316 and 318 @ 600. Very decent head but some turbulence was discovered. On the subject of cams I would like an opinion of Street Solid rollers? I was told that they do not have a good service life due to the lack of oil @ idle low speeds. Is that true? I'm sure it depends in the lifters? Can anyone elaborate on this? I would like to go to a Solid roller setup because I would like more out of my engine. I was shying away from hydraulic rollers because I've heard too may gripes about valve train stability in the higher rpm's

 

[451Mopar]

My old 451 had a street type solid roller cam [email protected] duration, 0.613" lift, and the regular style comp roller lifters (not the pressure fed ones) and I ran it for 10-years with no problems, but maybe only 30,000 miles combined street and drag racing. Engine dropped an intake valve (head of intake valve broke off) after 10 years, but the lifters looked fine when I took the engine apart.

 

[not so famous bob]

Myself I run the Indy dual plane intake on my 493 and I like it. Its like the RPM intake but has bigger ports and runners. Using an 850 DP mine has run 10.70's through the full exh on pump and driven to the track. On my cam I went with a custom flat tappet from Dwayne Porter and it is 264 & 270 @ .050 WITH .585 & .592 LIFT AND A 110 LSA. I have it on a 106 ICL. Ron

View attachment 554967

--------------------------what gears and tires? what weight ?

 

[383man]

--------------------------what gears and tires? what weight ?

I am running 4.30's using a 30 x 9 tire. Car weighs right about 3725 lbs with me in it. I turn about 3200 rpm at 60 mph on the highway with my 727 and a Dynamic 9.5 converter. Ron

 

[not so famous bob]

I am running 4.30's using a 30 x 9 tire. Car weighs right about 3725 lbs with me in it. I turn about 3200 rpm at 60 mph on the highway with my 727 and a Dynamic 9.5 converter. Ron

View attachment 555976

COOL, NICE CAR . Had a 63 once.