349 CI on the cheap

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70dartman,
This is the baseline cam that I came up with .540/300 255 @ .050 108 CL

HP flywheel --- HP net --- TQ flywheel --- TQ net

586 @ 6500 --- 457 --- 511 @ 5000 --- 458 Baseline cam

544 @ 6500 --- 442 --- 508 @ 4500 --- 448 this is cam 1

533 @ 6500 --- 436 --- 506 @ 4500 --- 443 this is cam 2

608 @ 7000--- 462 --- 510 @ 5500 --- 456 this is cam 3
 
BJR,
In your original post you had a compression ratio of approximately 12:1 to get these kind of HP and TQ numbers. If you were to drop down to say a 10.5:1 compression and use a more streetable cam, of your choice, what kind of numbers would you be coming up with? I would also assume that you would have to go to a little smaller carb in this case. I am not one to worry to much about how much of a bear it would be to drive as I prefer manual steering and brakes anyway, but I was thinking more along the lines of using pump gas.

Jack
 
Jack,
Using the pistons that I found in post 47 the compression would be 9.98:1 and with 93 octane pump gas and a .480/280 hyd. cam with a .055 gasket and 68 cc heads.

HP flywheel --- HP net --- TQ flywheel --- TQ net

511 @ 6500 --- 402 --- 480 @ 4500 --- 409
 
70, my thoughts were keep the cam small for a couple reasons. First, IMO, it shouldnt be reved. Why go bigger, pushing the peaks higher and making things more peaky when you shouldnt be revving it anyway (my opinion). Second, by not getting too wild in the cam, you dont have to modify any existing piston dome or releif for piston to valve clearance. Go bigger, you will. That's more $$.


BJR, That was exactly what I hoped you were envisioning. I just dont have it in the book I have that was printed by TRW in the 80s...lol. So that would be even less $$. On using the open chambers to make a positive deck quench engine...Have you actually tried that before? I have a .060 over 440 I am still making slow progress on when I have time. The biggest issue is the roof of the chambers, and the shape, are not consistent. So every hole, I have to clay the piston dome (KB quench domes) with the head in place, and work until it's reasonably flat. They have to be polished, because some of the surface casting roughness takes up .015" of that qunech..lol. Basically, it's a huge PITA, and not something I would call budget unless the skill level of the builder is worth nothing. For my stuff, that's the case. But for others' I'm doing it for..that's not. Poor execution by Mopar ruins a good idea...lol.
 
Those are impressive numbers for a streetable 318 block and the small valve 360 heads. This would be with the piston positive decked and thinner head gaskets to create quench would it not?

Jack
 
Moper,
For trying the above deck engines we have done this for a number of years, and yes your correct in that the chambers are different for each one, but because of machining, the heads the end cylinders are generally the smallest and the center two are the largest.
As for doing the work in the chambers, I didn't worry too much about this as for the street and mild performance applications and pump gas. I wasn't useing a race engine for street use and being street use the engine limits are much more tolerable and forgiveing.
I did a 400 CI engine this way a few years ago and ran it for 3 years with .020 out of the block, steel shim gaskets and low compression 440 pistons as there the same height as the high compression 383 pistons and are smaller than the 400 in bore size so the overbore lent it self nicely to the 400 @ .030 or .040, or .060. This engine made 535 HP with a .480 hyd. cam and a M-1 intake, 490 ft lbs of TQ and ran 7.0's @ 98 MPH. I also did a 360 .030 over with the pistons out .030 and did the heads as we have talked, and it ran 7.40's in a 3400+ lbs car. Also with the NOS it ran 6.90's with a 150 shot. This car has been running now for over 5 years.
My engine is on the stand as I had the front half of the car changed to a pro stock strut front suspension, as I did a wheel stand and destroyed the factory one that I had under the car, but it beats replaceing the hard to find body panels. I recieved the car from the chassis shop on saturday and I put a 402 CI engine back in as it makes 70 more HP and 50 more ft lbs of TQ than the 404 I had in there.
 
Coyote Jack said:
Those are impressive numbers for a streetable 318 block and the small valve 360 heads. This would be with the piston positive decked and thinner head gaskets to create quench would it not?

Jack
Click to expand...


Jack,
Actually the piston is .001 down with .030 off the deck and a .055 gasket and 68 cc heads.
 
Roberson_Tech said:
You have to give credit to BJR to come up with a new combo that is cheap and makes good Horse Power. Nice to see someone thinking and leading and not just following.
Click to expand...


Thanks! For the kind words.
 
BJR
I hate to keep asking you to work...LOL...But can you try these same cams w/ u head and 2.09 intake w/ 1 7/8 in header and a 2' header w/ the cams advanced 4 degrees ?....Lee
 
Thanks for the pm....I got mine working...I appreciate all that you have done...Lee
 
70dartman,
Run these flow #'s through your computer with the 1.88/1.60 valves, 168 cc's intake and 64 cc exhaust.

lift --- int./ext.

.100---96/89
.200---185/133
.300---229/181
.400---248/196
.500---283/201
.600---285/206
.700---281/207

does your program give efficentcy, if it does check out how they are, for stock castings.
 
I've been so busy that I havent had time to finish mine, all the parts are here but just don't have the time to assemble it right now. I should have it finished shortly.
 
Thats what you get for helping everyone out. LOL. Now finish that dam thing already.lol.I Still need to call you about my heads and build. I will be doing that shortly. Hope all is well with you BJR.
 
Yes everything is well here but right now I'm 5 + weeks behind in business, so be as patient as you can be, I'll get it done soon enough and let everyone know what it does.
 
Ive actually DONE the 349 / 360 crank stroker build...but it wasnt all plain sailing.

First...I used some forged TRW SP2260 slugs and shaved the crowns down .100th...I ended up with very little P-V clearance.

I have this problem with mine - I can't run a cam over .500 lift.

I used some specially welded 318 heads, but had to take the chambers to 63 cc to avoid RIDICULOUSLY HIGH compression.

So what I have now is:

10.8:1 comp
318 heads (63 cc open chamber)
and can only run a .495 lift cam.


I d really appreciate it if BJR or Moper can help me with the following:

What KB Forged slug can I use witha 360 rod that will keep my comp up around 10:1, but give me the P-V clearance I need to run a .540 lift cam?

Diamonds are NOT on the agenda because of cost.

Hope you can help?
 
dont you have to re harden your crank after a certain amount of grind. do you know the cost of nitrating(however you spell it) i think thats how you harden steel..
 
I think you mean the surface of the crank. They called nitraide or something like that.
You can have it done if you wanted to.
 
BJR Racing said:
Most cranks are tha same hardness all the way through whne they are manufactured.
Click to expand...

GEEEESSS,
My spelling sucks what the he** was I thinking........lol hardness is only .020-.030 thick so any grinding is going to remove the original hardness.
 
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