Camshaft recommendations/opinions - 393, MORE QUESTIONS 10/14

[JWMcCrary]

Looking at a refresh of my engine over the winter. It's 15 years old with very low mileage but I'm guessing has sucked in too much grit/dirt during that time off road. Still runs like a scalded ape but has blow by and will smoke if you lay into the throttle. I recently picked up a 351W roller block that started life in 1994 bronco that I plan to use with the internals from my current engine. With that said I will need a roller camshaft, lifters, and I'm guessing probably pushrods.

Current engine details from build sheet: (copy & paste)
351W Engine Block(D9AE-6015-ED-18) & Stock 351W Rods
Bored 40 over, honed and prepped with torque plate
Block decked for squareness
Durabond Cam bearings
3.85 stroke crankshaft
ARP rod bolts 150-6004
Stock rods resized
Keith Black KB115 two eyebrow flattop pistons
Clearance Pistons and Block for Crank Throw
Perfect circle rings
King Main bearings
King Rod bearings
Rotating assembly balanced (50 oz Balancer and Flywheel)

Edelbrock RPM aluminum heads with comp cams roller rockers
Edlebrock Performer intake with open 1" spacer
Holley Terminator fuel injection
Holley dual sync distributor (EFI controls timing)
BC Bronco shorty headers with 2in/2 out single magnifllo

Other factors for camshaft selection:
C4 Auto transmission with Transgo Kit, also 15 years old but still performing great.
4.30 gears with D20 Tera Low + Cold Duck doubler
37" tires

My thoughts are to have the 351W roller block bored .040, new cam bearings, and all the prep work done to install the internals from current engine. Obviously replacing all the bearings and new rings. Have the heads checked/done with new valve seals. Plan to ditch the comp cam roller rockers as they are very noisy. I have a set of Trick Flow roller rockers that I hope will be better.

I purposely didn't mention the current cam/specs s thato what is suggested won't have any influence from the current setup. I will say this, it works fine offroad when using lower gearing. On the hwy in 2WD high with 4.30 gearing and 37" tires it has some bog from a standing start that can't be tuned out.

Thanks in advance for recommendations/opinions. I know there have been numerous threads about camshafts but there are not many engines exactly the same. I've emailed a couple of popular Camshaft companies for their input but so far haven't received anything back. Not in a hurry so hoping for several opinions to research and think about before deciding.

 

[73azbronco]

best bet would probably be the guy at fordstroker dot com, he built a great camfor my 347

 

[Madgyver]

I got a hydraulic roller in mines. Had to do some clearancing on the 69 block (C9OE)

 

[vintage bronco]

Go Custom Ed Curtis @ Flowtech Induction

 

[Rightpace]

That block is a 79 model according to the numbers. I saw you mentioned a 1994 year bronco, just clarifying. Don't over do it with a huge cam, even with the aluminum heads, intake and free flow exhaust, balancing the rotating assembly and precision machining are the most important part.

 

[Rightpace]

Look at cams with around 260 duration. After that you will need a stall converter.

 

[68ford]

My 438 Windsor has a comp solid roller with 245ish/255ish@.050. .619/.640 on a 110 lobe sep. Obviously the engine is bigger but it make awesome power as soon as you step on the accelerator any amount. Hits 500ft lb before 3000rpm. Max 565hp 5600 and 570TQ at 4300. Idle is pretty choppy, but off idle power is still really good

 

[rguest3]

JWMcCrary - Along with the engine rebuild, are you sticking with the 37" Tires and the 4.30 Gear? Not much RPM available to go along with a Cam thats too big.

 

[Broncobowsher]

I just look at that parts list and think that it is going to be a fairly high compression engine. A little bit of cam will be needed just to keep the cylinder pressures in check.

Have you ran the numbers for the compression ratio yet? I wouldn't be surprised if it was around 12:1. Flat top pistons and aluminum heads, stroker, 60cc heads (the spec I find for the Edelbrock RPM heads)

 

[JWMcCrary]

That block is a 79 model according to the numbers. I saw you mentioned a 1994 year bronco, just clarifying. Don't over do it with a huge cam, even with the aluminum heads, intake and free flow exhaust, balancing the rotating assembly and precision machining are the most important part.

Correct, the current non roller block is from 1979, will be building the 1994 roller block.

 

[JWMcCrary]

I just look at that parts list and think that it is going to be a fairly high compression engine. A little bit of cam will be needed just to keep the cylinder pressures in check.

Have you ran the numbers for the compression ratio yet? I wouldn't be surprised if it was around 12:1. Flat top pistons and aluminum heads, stroker, 60cc heads (the spec I find for the Edelbrock RPM heads)

Compression ratio should be around 9.5:1, that's what I was told, I never calculated it, not sure I even know how. I gave all the info to somebody in 2005 when I built the engine and they told me but I can't remember the exact calculation, I do remember it was under 10. I remember them asking for the head gasket info as well, which is FEL 1011-2

 

[JWMcCrary]

This is the cam that is in the engine now that was installed when built. I've always wondered if it was a little too big and based on the comments it sounds like it is right at or slightly above the maximum recommended.

Thinking I need to find the roller equivalent of this but certainly nothing bigger.

 

[rguest3]

The Cam you have now is really not that big at all for the 393ci. Slight Lope maybe? I was really expecting you had something with a lot more duration.

My choice with the F4TE Roller Block, would be a Comp Cam XE266HR Roller Cam, Lifters and Timing Set. Similar to what you have now but more lift. Kind of the best of both worlds. Great torque and extra RPMs too.

Lunati VooDoo Roller Cams are worth a look at too.

Stepping up in Axle Gear will make a great improvement too. 4.88? Especially to help with the "Bog" you have now off the line.

 

[nvrstuk]

What Broncobowsher said... you really need to figure the CR! With flat tops, and who knows what CC heads you said from Edlebrock it would be hard to be under 10.5:1 or up to 12:1 CR.

This is imperative to know before asking for cam input. The .039" FelPro head gasket is also conducive to appr 12:1 CR.

I tried clicking on your cam spec link and it wouldn't link me to anything. Can you post the actual part or grind number?

People that suggest you need a big 5.0 cam in your 393 aren't understanding the many dynamics of a stroker... the main thing is even a small 393 stroker is over 30% larger than a 302!! You can't run a 302 cam in a 393 and expect any power! A 393 is essentially a BIG BLOCK so you need a big block sized cam in it- hope this makes sense.

A 393 is not going to lose or not have enough power with a bigger cam. What Wayne was saying earlier is not unreasonable at all. Having a 215-225 dur at .050" is WAAAAY too small. There is soooo much more than simple duration and lift but you need at least the high 230's duration and high 5's for lift (.555" lift at .050") to properly feed this thing ... or why build a stroker? Cam timing, valve opening timing, overlap all play huge parts.

Contact Ed at http://www.flowtechinduction.com/ via email and he will custom build at only a few dollars more EXACTLY what you tell him you want.

IF you contact Comp or whoever expect to get 3 different answers from 3 different "experts". You will ! Get the guys name and call back and get a different answer from the next expert. I did it 3 times and was blown away... called Ed and got what I asked for.


Your cam link didn't work. Could you post the Part number or grind number?

 

[Itsa67]

Go to the Jones Cam Designs website and fill in your info in the cam recommendations section. Mike will send you an email with his suggestion for one of his cams (that actually includes the basic specs). If nothing else this gives you an experts opinion on what would work best for your combo. Ed at Flowtech is really well respected as well. The correct cam will definitely bring a smile to your face.

 

[JWMcCrary]

Your cam link didn't work. Could you post the Part number or grind number?

I didn't post any links, I had a pdf attached with all the cam info.
Product Line:COMP Cams Xtreme 4x4 Camshafts
Summit Racing Part Number:CCA-35-239-3
Manufacturer's Part Number:35-239-3

I've been running this engine for 15 years, my goal here is to switch from a non roller block to a roller block and have a fresh engine. To do this requires a different camshaft. The camshaft above, hydralic flat tappet, which is in it and running right now, was recommended by the machine shop that built that short block in 2005.
Not intending to cheap out but have been happy with the engine and all my internals should be good, just need freshening up and new bearings and rings, have the heads freshened up, etc.
I think I'm finally convinced you guy's are right on the compression ratio, plugging what I know into a calculator I'm getting 11.3:1. But it runs good, just getting some blowby and a little smoke if get hard in the throttle.

 

[nvrstuk]

I clicked on the cam spec highlight, couldn't open until it downloaded on my computer then opened... anyway...

You need to have someone like Ed design a cam that will "bleed" off some of that compression unless you can have access to a much octane than is available at 99.9% of most gas stations.

Glad you checked out the numbers. I've spec'd out several 393's and with flat tops with valve reliefs and a typical OE cc chamber you are ... where you are...

Good luck on your build.

 

[JWMcCrary]

design a cam that will "bleed" off some of that compression unless you can have access to a much octane than is available at 99.9% of most gas stations.

This just mind boggles me. Been running pump gas for 15 years and it has always run fine. When I added the Holley EFi and the dual sync distributor I asked one of the guys at the counter at Summit about someone who could check things out for me after the install since I'm a novice at EFI. They recommended Big 3 Racing, very reputable place near Cleveland. After getting it all installed and running I took it to them and left for a couple of days. The only thing they changed was pull some high RPM timing out of it and verified the timing was in sync as RPMs increased. Rick Trunkett did the tuning himself and commented how well it ran, he's also the one who told me with the tire size in high range I would have to live with a little bog. With everything in low off road (approx. 82 to 1) it has always performed great. I've never had a situation where lack of power was the problem.
I guess numbers don't lie, but it has sure never ran like a high compression engine. Here are a few pics from 2005 when it was put together and still running today.

 

[nvrstuk]

Well, somebody did "something" to allow the use of regular 87 octane in a 11:1 CR old skool (not variable timing or any other cool latemodel modern day tech) engine.

I've built more than a few engines and many back in the leaded gas, 101 octane at the pump days and it's pretty much a given that 11:1 in an old skool engine needs an octane rating that is not available at the pump today.

 

[73azbronco]

I clicked on the cam spec highlight, couldn't open until it downloaded on my computer then opened... anyway...

You need to have someone like Ed design a cam that will "bleed" off some of that compression unless you can have access to a much octane than is available at 99.9% of most gas stations.

Glad you checked out the numbers. I've spec'd out several 393's and with flat tops with valve reliefs and a typical OE cc chamber you are ... where you are...

Good luck on your build.

This, mine has almost 12 cr, but well designed cam results in a dynamic more like 9.2, regular gas.