Trying to get 300+rwhp....

mcbride66coupe

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Sep 18, 2004

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Wahiawa, Hawaii

Mar 31, 2005

#1

• Mar 31, 2005

• #1

Just purchased the Edelbrock RPM package (RPM Air-Gap intake) Do you think this will get my 302 close to 300 rwhp? Does anyone have this setup on there 302? Should I sell the RPM Performer cam and step up to a bigger one? It will be my daily driver...if I do step up will it take me below 13mpg highway? I have an AOD tranny gonna go with prob 4.10 gears. If i should step up my cam give me suggestions. Thanks

 

brianj5600

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Sep 19, 2003

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#2

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I am not a fan of ede carbs, but the rest looks good? Any idea what the cr will be with those heads? That could be another obstacle.

 

302 coupe

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#3

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you'd need about 350-360 horses at the fly to get 300 at the wheels. The RPM package, according to edelbrock, I think the list at 367 hp, so you should be ok. Also, if you got the heads with 64 cc chambers, your compression will take a hurting. I think the stock 289 heads were 54-55 cc chambers, so going to a 64 cc chamber would drop you nearly a full point in compression, down to about 8.4:1.

Personally, I would not run an edelbrock carb on it either. I've really taken a liking to 650 dbl pumpers on modified small blocks lately. The Eddy carb will likely work ok, but you'll need to get a calibration kit and have it dyno tuned for best performance, that holds true for any carb though.

 

Stang_1973

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Jul 13, 2001

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San Antonio, Tx.

Mar 31, 2005

#4

• Mar 31, 2005

• #4

Looks like a Mad little 302. Nice setup.
If you are completely ripping apart the engine, I would suggest you get some pistons. This will help against losing compression from the bigger chambers on the heads. I am not really biased on Edy vs. Holley, but from what I hear, Edy deos not get out of tune as much as Holley. I have a Holley, I know I need a tune soon.

If you get the 367 listed HP, you should be right around 300HP at the wheels, although I am not sure about the % loss through that AOD, i hear they can steal quite abit of power. But the Overdrive is nice, especially for a DD and gas prices.

 

mcbride66coupe

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#5

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The heads are 60cc, is this gonna cause me a big problem? If i do get new pistons, what would you suggest? How much does the compression ratio affect performance? Any suggestions are helpful, I have a month left and still have a GOOD chunk of change to spend on it so let me know that way I am sure all my priorities are right.

thanks
cheyenne mcbride

 

302 coupe

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#6

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With the 60cc heads, you should be in the high 8:1 range, maybe 8.8:1 or so. Not bad, per se, it would be very pump gas friendly, 87 octane wouldn't be a problem, but you will give up some power. If you get new pistons, you'll have to get the block bored and honed, get the pistons pressed on the rods, get new rings, rod bearings, etc., basically a complete shortblock rebuild. If your engine is fairly fresh, I'd leave it as is. There's maybe a 15-20 hp difference caused by the lower compression, versus say an enigne with 10:1 compression.

 

Bullitt

Packin' Heat

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#7

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rule of thumb for compression is 3% power increase per 1 point of compression.

an estimate, but it'll give you some idea.

 

302 coupe

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#8

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true, but since he has a cam that likes a little more compression, I figured the difference to be a little greater.

 

mcbride66coupe

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#9

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My engine was rebuilt less than 500 miles ago. If I changed to a little more aggressive cam, would that help make up the difference in HP from losing the compression? If I do bump up to a different cam what cam should I go with....that I can still stay at least 13 mpg highway?

 

6

'69Stang

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#10

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Compression...

The compression ratio with flat top pistons (+4cc), 60cc combustion chambers, and a .030 overbore should yield about a 9.43:1 compression ratio.

That's a decent sized cam to begin with so I don't think you want to go any bigger. If you want more power than think about a roller cam. This would help with the engine idle characteristics also.

 

brianj5600

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#11

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A thinner gasket would help if the pistons are below the deck. I've heard of .025" being safe piston to head clearance, mine are at about .033". If your pistons are .020, hg choice could help a lot.

 

12sec67

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#12

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• #12

i shaved my heads .030 THOUS. to obtain my 10.5:1 and still have plenty of clearance to valve to piston clearance.

also the 367hp obtained by edelbrock was also on a hydro rollor 5.0.

i used a 750 edelbrock on my set up for a while. at the track i used my special jets...i ran 12.6's with it with the drilled out .119 jets in the front and little bigger drilled out .119 jets in the rear for more fuel.

 

mcbride66coupe

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#13

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12sec67 What setup are you running as far as heads and intake etc....etc....If i go with the roller cam, what else do I have to change?

 

12sec67

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#14

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• #14

mcbride66coupe said:

12sec67 What setup are you running as far as heads and intake etc....etc....If i go with the roller cam, what else do I have to change?

Click to expand...

performer rpm's 2.02/1.60's with 1.6 rockers and a .512 lift cam. performer rpm intake and a 1" carb spacer with a 650db. flat top hyper pistons, windage tray, 8 quart pan, summit headers, underdrive pully kit, AOD aluminum driveshaft, 9" rear with trac-loc 4.11,

you would need to rework you block for roller lifters to use the roller cam and the lifter retainer and from what i understand it is cheaper to build a new one then try to change one over to roller.

 

12sec67

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btw- like the look of your car, it looks like my cousins- he is running a cowl hood with the same rims and lower stance and charcol gray

 

mcbride66coupe

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#16

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thanks for all the help....im worried that i wont be at 300rwhp....maybe i will just have to live with that for now and start a new setup in the future.

thanks

 

12sec67

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#17

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mcbride66coupe said:

thanks for all the help....im worried that i wont be at 300rwhp....maybe i will just have to live with that for now and start a new setup in the future.

thanks

Click to expand...

i would at least try to get some thinner head gaskets to boost you compression...

all you can do is try... your combo might get you there. i was hoping for at least 300rwhp/300ftlbs and i was also told i wasn't going to have the numbers i was going to get.

 

69Rcode_Mach1

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Apr 20, 2004

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Apr 1, 2005

#18

• Apr 1, 2005

• #18

I would just mill the heads, taking out the pistons will open up a can of worms if you are on a tight budget. You will need to hone the block, check for taper, possibly bore the block, hot tanking, get the rods magnufluxed and shot peened, ARP rod bolts, new bearings, engine would have to come out, and may run into other problems. The best way is to just do a full out bottom end up build up, but that all comes down to money. I took off the heads, found out I had 8:1 compression pistons in there from the previous owner. I am redoing the engine and will be eighteen this sunday. I have no cash to finish it up, trying to get a job, and am no longer living at home(parents are jackasses). All of this without a car, so ineed to get a beater car to drive till I finish the mach. I would recommend just milling the heads fornow and when you have enough money taking the engine out and finishing it from the bottom end.