engine combination

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jeffs67dart

jeffs67dart

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just wondering if cubic inches and compression ratio is enough to support the cylinder heads I'm buying. alright I have a 360/380 hp mopar crate engine in my 67 dart. I took it to the drag strip and it ran 13.28 and I was hoping for more, I know with some tuning I might have gotten a little more but probably high 12's at the most so of course I want more, was going to supercharge (still might later) it but decided to change heads and cam instead. I bought edelbrock performer rpm and going to take them to modern cylinder head for a full cnc port job and replacing the cam. the camshaft I'm thinking of going with is a comp cams hydraulic roller with 236 and 242 duration @.050 an .544 and .541 lift with 1.5 rockers but I'm going to be using 1.6 rockers so the lift will be close to .600. just wondering what you think of the cam selection and if 360 cubic inches and 9.0:1 compression will work ok with those heads (the heads on the engine now are 62cc and the edelbrocks are 58cc so I should have a little more compression). what do you think?
 
Uh, WHUT? What do you have for trans / rear gear / tires? Converter?

A 380 hp ought'a be faster than THAT
 
you might want to check with MCH about the cc on the heads after the CNC...the chambers cc will be larger then before the heads were CNC...
 
Double agree, tire size, transmission, gear ratio. What was your reaction time, your 60ft time. What was your speed. 13 seconds, hope you was running 1/4mile. What was the rpm's at the end of the track?
 
Probably should have changed the car first. whoops.
 
it has a 904 trans with a 8 3/4 sure grip rear with 3.91 gear, with 255/60r15 mickey Thompson drag radials. I thought it should be faster to. also it has tti step headers with a 750 double pumper holley. my 60 foot time was 1.90 and my trap speed was 103. but even if it runs mid 12's I want to go faster and I already bought the heads so just wondering if the heads and cam will make goo power with my combination. I would like to run mid to high 11's if possible. and I made 3 passes and they were pretty consistant.
 
It missing something in the tune up is my guess. It's at least 5 mph slow from what it should run unless the car weighs 3800#. I'll guess a fuel delivery issue, maybe timing. Hard to say, could be really fat. Post the entire timeslip, all incrementals.

IMO with it tuned, pulling and launching right, it should run a high 11 in the 108-112 range. The high end of that MPH range

Throwing money at it is not the best approach. Find out why it's not performing. Putting more power/dollars to a poorly performing rig, just gets you a more expensive poorly performing rig. Just my opinion.

Here's an example. 71 demon 360, 9.5:1, stock heads with 1.94 valves, xe268h, LD340, OOTB 750DP, headers, 2500 converter, 2.94 gears. It ran 105 mph at 4500DA and was still fat. Had more in it. That engine made 347 hp on a dyno.
 
was the 347hp to the wheels or flywheel? theirs no way this his car will run high 11's with the combination I have now. I did read in a hot rod magazine where they put this same engine in a 65 valiant and it ran 12.49 (basically same car I have) but it had fender headers and better exhaust. I'm sure I can get a little more out of my combination but not in the 11's like your saying. when I change heads and cam was planning on a dyno tune before taking it to the track (would try to make changes at track but most of the time you can only get in 3 to 4 passes in). I want this car to easily run in the 11's
 
Had cars with less than what you have now run 11's. 347 at the flywheel. If it had 347 at the wheels and ran 105, it would have been a dog.

ET is chassis and converter. Reminds me of my friends 11.20 car that runs 132mph. He wants more hp. LOL Only change I might make to the engine would be putting a dual plane (air Gap) on it if it has a single plane intake now.

60' good for ET, crappy for MPH. Have at it and good luck.

Tell me you have less than this combo? One of the many I know.

360 started as a .040 over Napa rebuilt short block. I took it apart to check everything. I had the block decked (deck .015 head 63cc., gasket .028, compression 10.51)reversed the cast dished pistons on the rods and put in good rod bolts and had the rods resized. Manley cam .443 lift [email protected] lobe seperation was around 108. J heads pocket ported with 2.02 int. valves and 273 adj. rockers, LD340 intake with a 1" 4 hole spacer, Vac. 750. For exhaust heddmen 1 5/8" headers, 3" exhaust with ultra flows ending at the axle. 904 with a Dayco 2,400 stall converter and 8 3/4 with 3.91's the slicks were*8"x*26"x*14". Suspension consisted of 6yl. bars and comp. eng. adj. shocks in the front and 002/003 superstock springs with Mopar perf. 50/50 xtra long shock in the rear. The car was a 70Valiant*4*door it weighed 3,320 with me in it. With an*electric water pump*drive, 5/16" fuel line with holley mech. fuel pump and a homemade fresh air intake (dryer*hose and a dual snorkle air cleaner)the best run was 11.96/113 but it typically went 0's and teen's in decent air. Typical 60'was low 1.70's. With a looser converter maybe around 3,500 stall it probably would have gone 11.70's or 80's.
 
Big cam and heads aren't a good combo for 9.0-1 compression. Zinging the heck out of it "might" help. But as most have stated, there should be more in what you have.
Race only or dual purpose?
 
it's a street car, may take to track 3 or 4 times a year. the torque converter is a hughes 10", 3000 stall. maybe I will save these heads and build a better short block with more compression to put these heads on and tune my set up to get better times
 
that does seem slow for the 380hp crate motor. The 2009 drag pak 5.9l challengers ran in the mid to low 11's at 3250lbs and they actually had a cam with a .480 or .490 lift at the valve. numerous other a-bodies in the mopar action magazines over the years ran n the mid 11's with the 380 crate motor. Wish I could find where I put all those old mags. Pretty good set up info in them for the crate engines heck I even remember seeing the locomotion in one from the early 2000's
 
jammied said:
that does seem slow for the 380hp crate motor. The 2009 drag pak 5.9l challengers ran in the mid to low 11's at 3250lbs and they actually had a cam with a .480 or .490 lift at the valve. numerous other a-bodies in the mopar action magazines over the years ran n the mid 11's with the 380 crate motor. Wish I could find where I put all those old mags. Pretty good set up info in them for the crate engines heck I even remember seeing the locomotion in one from the early 2000's
Click to expand...

You are correct that a properly tuned 360/380 hp Magnum crate, drivetrain & chassis can get into the 11's, but it's not easy. Hot Rod(?) magazine did a crate shootout between the big 3, and got a 360/360hp Commando equipped Duster into the high 11's with a lot of bolt-on work.

However, the 360 drag Pak Challenger 5.9 is a different 360 combo, including higher compression and fuel injection, among other things. The few that have been run in the Stock class are deep in the 10's. Thanks for the mention, but since 1999 my 360's have always been based on the 360/300hp Commando. I've run 11 teens @ 3,540+ lbs, but that's after years of refining and optimizing many legal Stock class mods. Despite the results, I don't know if I'll ever get it to it's "full" potential (If time and $$$ wasn't a concern.)

Best thing to do is refine what is in place instead of trying to buy more horsepower. One can have 500 HP and not be able to get it into the 11's if everything else isn't working together. But being mostly a street car, there will be compromises that will limit it's full potential.
 
WOW I had no idea that you got your car that quick but I remember being impressed with it! I have found the drag pak computer and wiring harness for a little under a $900 so that will prob be my next build wish I could find the cam specs for it
 
You are correct that a properly tuned 360/380 hp Magnum crate, drivetrain & chassis can get into the 11's, but it's not easy. Hot Rod(?) magazine did a crate shootout between the big 3, and got a 360/360hp Commando equipped Duster into the high 11's with a lot of bolt-on work.
Click to expand...

Yup, that was Hot Rod Magazine in 1993. The Duster didn't go faster than 12.17 @110 (corrected or altitude) though.
 
stixx said:
Yup, that was Hot Rod Magazine in 1993. The Duster didn't go faster than 12.17 @110 (corrected or altitude) though.
Click to expand...

You're probably right. But I thought I read somewhere that they barely got into the 11's after some more work after the article came out. I have the article "somewhere", but don't remember where the high 11's info came from.
 
I agree with that's there more in your combo with some work. However if you are wanting to go faster then go ahead with your planned upgrades.

If I were in your shoes and were stepping up the first thing I'd do would be measure the piston to deck height and cc the piston so I would know exactly what chamber volume I needed to get the compression ratio needed. Personally I'd want 10.8-11.0 to 1, that cam in a 9.0 or 9.5-1 engine is a recipe for disappointment. Plan on buying or having you converter re stalled

I ran a similar built 340 several years ago. The cam was a Hughes hydraulic flat tappet with almost identical specs. Ported Edelbrocks, 11.4-1, Weiand X-Cellerator, Quick Fuel 750, TTI 1 5/8- 1 3/4 step headers, 727 with a 9.5" converter that flashed 5000. The car ran pretty much the same with 3.91s or 4.30. It ran 7.24 in the 1/8 and 11.61 in the 1/4 at 3240# on pump 93 with a mechanical fuel pump and factory 5/16 fuel lines. I'm sure the 1/4 mile numbers would've been better with a decent fuel system. It would 60' in the low 1.50s.
 
Locomotion said:
You're probably right. But I thought I read somewhere that they barely got into the 11's after some more work after the article came out. I have the article "somewhere", but don't remember where the high 11's info came from.
Click to expand...

That is accurate. I spoke with a good number of racers running the 360/380 create engine. In an A body race car they were running low 12's to high 11's. No to the peoples here, re-read that and notice the key word, "Race Car." In other words, gutted, high gears and stall with slicks and skinnies.

The OP has a lot of good goodies on the car. But your weight, gear and tire selection is a hinderance. Swapping to an Edelbrock head is a movein the right direction and a benefit if you can get that compression ratio up. And yes to the 1.6 rockers. TAKE advantage of that heads flow!!!

Do remember that this create engine is not a race engine. The cam is a nice street grind that should beable to perform well. Not great

I'm at sea level. How about yourself?
 
Just my thoughts and opinion. There is easily a full second of et left on the table with your current combination. Now it more than likely is going to take a more money to get it quicker. If my memory serves correct a 3800 stall converter is in the ball park for your combination. Also checking and adjusting driveline angles would help a lot if they are not correct. How big is the air filter that you are using? Guess if it were me get the details correct on the combination and to its full potential then start throwing money at a bigger top end.

So here is my list

1. atleast a 14x4 air filter
2. a good 3800 converter
3. check driveline angles
4. tune timing curve

Get what you have into the low-mid 12's high 11's isn't out of reach for it. Then to get into the mid to low 11's a pair of 2.02 eq iron rams will get you there a vacuum secondary carb would probably help just depends on how good the dp you have now is set up. The engine you have now should run low 12's high 11's when setup. Then drop a pair of heads on it.
 
rumblefish360 said:
That is accurate. I spoke with a good number of racers running the 360/380 create engine. In an A body race car they were running low 12's to high 11's. No to the peoples here, re-read that and notice the key word, "Race Car." In other words, gutted, high gears and stall with slicks and skinnies.

The OP has a lot of good goodies on the car. But your weight, gear and tire selection is a hinderance. Swapping to an Edelbrock head is a movein the right direction and a benefit if you can get that compression ratio up. And yes to the 1.6 rockers. TAKE advantage of that heads flow!!!

Do remember that this create engine is not a race engine. The cam is a nice street grind that should beable to perform well. Not great

I'm at sea level. How about yourself?
Click to expand...

Was it the 65 Valiant? The one with 3.55's and no mention of a converter and a 8-9" tire from what I reacall. It was over 3300# This one?

hrdp_9810_16_o+1965_plymouth_valiant_engine_swap+blasting_off.jpg


Had street cars with less that would put a whopping on it...

IIRC, Ron Silva's valiant ran 11.70's with a 360/380 engine.
 
sounds like an induction issue. i ended up having someone look at my set up and ended up being the carb out of whack. i have the same motor but with unported edelbrock heads with 1.7 rockers. ive ran a best of high 11 @ 113. your combo sounds right you just need to dial it in
 
that is the article I saw in hot with the valiant. like I said I know theirs some left but 11's would be very hard to get. google horsepower/quarter mile calculator and put in 380 horsepower and 3300 to 3400 lbs. with me in the car and see what it says. it don't say 11's period. you guys must be super tuners. my original question wasn't about my current combo but if the eddy heads and bigger cam will work well with the lower compression and 360 cubes. and like I said earlier I may supercharge this later so the lower compression is good.
 
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