Early A mild 360 build

[Jakenks]

Good morning all, I recently came upon a 65 Barracuda in decent shape that I'm putting back on the street. The 273 4 barrel (according to the fender tag) is long gone and I'm now working with a late model (80s?) 360 with the Holley version of the Carter two barrel from that era. This is hooked up to a 904 auto box (assume stock converter) and an 8.25" rear axle with a 3.23 ratio (approx). What I want is to increase the go power a bit, street only, this car will never see the strip. The engine runs through cast iron manifolds and I don't have plans for headers at this time. I have an Edelbrock Streetmaster intake and an Edelbrock 600 CFM carb that I could use. What I'm interested in is a recommendation for a camshaft that would help out the performance within the parameters noted. I have some ideas, but have never spec'd a cam for a small block mopar. I'll be changing valve springs with whatever cam I choose. Depending upon recommendations, I am ok with milling the heads and or using a thinner gasket to bump up compression a bit.

I look forward to any suggestions.

 

[Plymouth 65]

Good morning all, I recently came upon a 65 Barracuda in decent shape that I'm putting back on the street. The 273 4 barrel (according to the fender tag) is long gone and I'm now working with a late model (80s?) 360 with the Holley version of the Carter two barrel from that era. This is hooked up to a 904 auto box (assume stock converter) and an 8.25" rear axle with a 3.23 ratio (approx). What I want is to increase the go power a bit, street only, this car will never see the strip. The engine runs through cast iron manifolds and I don't have plans for headers at this time. I have an Edelbrock Streetmaster intake and an Edelbrock 600 CFM carb that I could use. What I'm interested in is a recommendation for a camshaft that would help out the performance within the parameters noted. I have some ideas, but have never spec'd a cam for a small block mopar. I'll be changing valve springs with whatever cam I choose. Depending upon recommendations, I am ok with milling the heads and or using a thinner gasket to bump up compression a bit.

I look forward to any suggestions.

Make sure to check the torque converter crankshaft register diameter. The 65 904 used the small diameter register. The 360 crankshaft register is larger diameter. You can either use a bushing or buy a later model 68 and up torque converter. Depending on the camshaft you select you may also want a higher stall converter. In that scenario, I would recommend purchasing the larger diameter register converter. At minimum I would recommend you use the stock 360 4 barrel camshaft. The carburetors with that cam should be 650 cfm max. 65'

 

[Plymouth 65]

Make sure to check the torque converter crankshaft register diameter. The 65 904 used the small diameter register. The 360 crankshaft register is larger diameter. You can either use a bushing or buy a later model 68 and up torque converter. Depending on the camshaft you select you may also want a higher stall converter. In that scenario, I would recommend purchasing the larger diameter register converter. At minimum I would recommend you use the stock 360 4 barrel camshaft. The carburetors with that cam should be 650 cfm max. 65'

One more thing, if you go with the larger diameter register converter you will have to change the input shaft, pump, and clutch hub in the 65 904 transmission. The early 904 62-67 used the small diameter input shaft.

 

[AJ/FormS]

Will there be hiway cruising involved?
If no, the fastest,cheapest,easiest road to a bit more go-power is TM,Torque Multiplication. Get some 3.73s or better and have BIG fun.

What manifolds are on that 360? they may be a choke.

 

[lroman]

Good morning all, I recently came upon a 65 Barracuda in decent shape that I'm putting back on the street. The 273 4 barrel (according to the fender tag) is long gone and I'm now working with a late model (80s?) 360 with the Holley version of the Carter two barrel from that era. This is hooked up to a 904 auto box (assume stock converter) and an 8.25" rear axle with a 3.23 ratio (approx). What I want is to increase the go power a bit, street only, this car will never see the strip. The engine runs through cast iron manifolds and I don't have plans for headers at this time. I have an Edelbrock Streetmaster intake and an Edelbrock 600 CFM carb that I could use. What I'm interested in is a recommendation for a camshaft that would help out the performance within the parameters noted. I have some ideas, but have never spec'd a cam for a small block mopar. I'll be changing valve springs with whatever cam I choose. Depending upon recommendations, I am ok with milling the heads and or using a thinner gasket to bump up compression a bit.

I look forward to any suggestions.

As far as cam selection goes, IMO, your best bet would be to call a manufacturers tech line and tell him what you have and where you want to be. Those guys can tailor a specific cam just for your needs. You might also call a builder that is mostly familiar with the small blocks like Hughes Engines, MRL Performance or Mancini Racing and take advantage of their experience rather than throwing it out for conversation. They might even have something on the shelf that fits your needs. Good luck with your project.

 

[AJ/FormS]

keep in mind that making power always takes rpm.
If your current cam powerpeaks at 4500rpm; with 3.23s and 25.5inch tires, this is about 43mph.
The next bigger cam will make more power, but it will come at a cost of about 200rpm higher, now 45mph,and so on.
Whereas 3.73s will bring the current power-peak down to 37mph! (still 4500rpm), and
4.10s will bring it down to 34mph!
The 2.74 low-gear,A998 and 3.73s will bring the power-peak down to 33mph!

Gears bring not only the mph of peak power down, but also all the other mphs in between will have more power, as well as those after.
There is no other modification that you can do to your engine that will do this, short of supercharging it.

Now, gears work by multiplying your engines torque.
Lets say you currently have 320ftlbs at 3400rpm. With your current 904 and 3.23s this works out to 320 x 3.23x2.45=2532 ftlbs peaking at 32mph.
Lets say you went with an A998 and 3.73s. This would work out to 320 x 3.73 x 2.74 =3270ftlbs, now at 25 mph. You see how that works? You now have a peak that is 3270/2532= plus 29% and it comes in at 32/25= 28% sooner!And all mphs will enjoy this torque boost.
Get yourself a 2400 or a 2800TC, and you will forget all about a bigger cam for a good long time. Oh, and a SureGrip, cuz that 2bbl is gonna boil both rear tires, nevermind just one.

Anyway, I know you asked about cams but, with the stock compression ratio in that 360, almost any cam you put into it will be a disappointment, until the gears and TC go in, so you might as well start with gears and a TC,IMO.

keep in mind the above increase of 29% and 28% sooner.
The next bigger cam might get you 5% more power, at the rpm of peak power, and it will come in about 5% later,in terms of mph. A cam 4 sizes bigger with compression, and support works keeping up, might get you 4x 5% =20% more power at the rpm of peak power, which will now also be some 20% later up the mph band or about 50 mph now. Yes there will be a power increase in the lower mphs as well, but no where near as significant as gears. And in fact without a TC upgrade, the power below 2000rpm will actually be significantly less, and even worse if the compression is not also brought along.

So these are your options;
29% more power 28% sooner, giving up the hiway cruise comfort.
OR; 5% more power and 5% later, or up to say 20% more power, coming in 20% later, and a soggy bottom end. Then to get rid of the soggy part, Gears and TC; again giving up the hiway cruise comfort.
There is a third option;
It's called compromise, and almost everybody does it.
You have a lightweight A. It comes in about 400 pounds lighter than the next generation. This is already about an 11% advantage. Meaning you need only 89% the power we need for equivalent go-power. That is over 2 cam sizes. Guess what size cam is in that 360 2bbl engine? Ok I'll tell you; almost the perfect cam for that engine.
So, all you need is to release the power a little sooner. The A998has a 2.74 low gear in it that is 12% better than the A904. This will let you keep the 3.23s, cuz the equivalent A904 gear would be 3.23 plus 12% or 3.61s. So that would let you keep the hiway cruiser gear of 3.23. Or you could go with the A999 and 3.55s and reap a double helping of TM, yet the A999 has a loc-up TC that is worth maybe 100 rpm at 65mph.Plus the A999 has a slightly higher stall.These changes will release the power that you have slightly earlier, a compromise.
The icing on the cake would be a 4bbl and a free flowing exhaust. This combo doesn't need headers, but you are gonna need the best manifolds available and big primary pipes, from the logs to the mufflers.Alternatively a pair of expansion chambers under the front seats . And finally, put some valve springs on it to hit 5500 or so.(you probably want to at least check the bearings).
Trebleg can help you with the manifolds.
After that, you will have to do a little tuning to get everything synced up.
This combo will cruise at 2770 with 25.5 tires, and the TC locked.And will rocket off the line with 23% more take-off TM. And will carry first gear to over 40 mph. The loc-up TC is about 2250 vs 1700 on the current stocker. This too will release a few more ftlbs to get you going.
Good luck with whatever you decide.

 

[Jakenks]

Will there be hiway cruising involved?
If no, the fastest,cheapest,easiest road to a bit more go-power is TM,Torque Multiplication. Get some 3.73s or better and have BIG fun.

What manifolds are on that 360? they may be a choke.

There will most likely be some highway cruising done. 3.73s are fun though. The manifolds look like typical A Body manifolds for a V8. headers would be better, but I'm not sure I want them, given the difficulty putting them on an early A.

 

[Jakenks]

One more thing, if you go with the larger diameter register converter you will have to change the input shaft, pump, and clutch hub in the 65 904 transmission. The early 904 62-67 used the small diameter input shaft.

everything is already done and installed by the PO. Supposedly, that is taken care of, but of course I'll check it all out.

 

[Jakenks]

As far as cam selection goes, IMO, your best bet would be to call a manufacturers tech line and tell him what you have and where you want to be. Those guys can tailor a specific cam just for your needs. You might also call a builder that is mostly familiar with the small blocks like Hughes Engines, MRL Performance or Mancini Racing and take advantage of their experience rather than throwing it out for conversation. They might even have something on the shelf that fits your needs. Good luck with your project.

I will most likely do that, but there is a wealth of practical application experience here that it is likely someone may have had or done a minor project like this. It is always great to hear what actually worked for others, and there seems tto always be more than one solution to a situation.

 

[lroman]

keep in mind that making power always takes rpm.
If your current cam powerpeaks at 4500rpm ; with 3.23s and 25.5inch tires

AJ, you're talking apples and oranges. Peak torque and peak horsepower are two different animals. You peak horsepower is dependent on torque X RPM divided by a constant (5252). Your torque generally peaks in the mid 3000 range. Small ports make for good low end velocity and thus better cyl. filling and better response. In reality, how many times do you have a chance to hit your red line if you just have a street car. I guess you could....buy why?

 

[AJ/FormS]

hi

AJ, you're talking apples and oranges. Peak torque and peak horsepower are two different animals. You peak horsepower is dependent on torque X RPM divided by a constant (5252). Your torque generally peaks in the mid 3000 range. Small ports make for good low end velocity and thus better cyl. filling and better response. In reality, how many times do you have a chance to hit your red line if you just have a street car. I guess you could....buy why?

I am not confused.

 

[1969reddart]

Anyway, I know you asked about cams but, with the stock compression ratio in that 360, almost any cam you put into it will be a disappointment, until the gears and TC go in, so you might as well start with gears and a TC,IMO..

Low compression 360's are easily capable of mid to high 13 seconds in the quarter mile in an A body. They make great little street engines and run on crap gas. This can be accomplished with a mild cam, 3.23 gears, stock converter and good flowing exhaust.

 

[AJ/FormS]

Low compression 360's are easily capable of mid to high 13 seconds in the quarter mile in an A body. They make great little street engines and run on crap gas. This can be accomplished with a mild cam, 3.23 gears, stock converter and good flowing exhaust.

Good morning all, I recently came upon a 65 Barracuda in decent shape that I'm putting back on the street. The 273 4 barrel (according to the fender tag) is long gone and I'm now working with a late model (80s?) 360 with the Holley version of the Carter two barrel from that era. This is hooked up to a 904 auto box (assume stock converter) and an 8.25" rear axle with a 3.23 ratio (approx). What I want is to increase the go power a bit, street only, this car will never see the strip. The engine runs through cast iron manifolds and I don't have plans for headers at this time. I have an Edelbrock Streetmaster intake and an Edelbrock 600 CFM carb that I could use. What I'm interested in is a recommendation for a camshaft that would help out the performance within the parameters noted. I have some ideas, but have never spec'd a cam for a small block mopar. I'll be changing valve springs with whatever cam I choose. Depending upon recommendations, I am ok with milling the heads and or using a thinner gasket to bump up compression a bit.

I look forward to any suggestions.

 

[Jakenks]

I've though about the 68 four speed 340 cam or maybe the auto box version. Opinions?

 

[273]

What AJ/Forms is saying. Is gears give you the most bang for the buck.

Take my car for example 400 hp create engine with 2.96 gears. I was majorly disappointed in its performance until I left it in first drove it up to 40 mph then floored it that I got any sense of the power it has.

I bet a stock or semi stock 360 with 4.10 would walk all over it at in town speeds.
Even though I have more power and a pretty broad power curve.

When I swap in 3.91 I'll be able to experience the power from a stop all the way to 40-60 before I have to let off the gas and more in the 1/4 mile.

As for peak torque vs hp. Peak hp is where your car is most powerful above and below it power falls off but less so below. All the torque curve tells you about your engine is what the under the curve hp looks like.

 

[Jakenks]

The gearing position is valid, except I don't want to change gears. I plan on driving some distances on the highway with this car, so I'd choose not to change a gear. Don't get me wrong: I've run some very strong cars back in the day, and gearing is an essential part of a strip car, or street strip. I'm shooting for something less than that. I want a cam that will give me better than the stock two barrel cam and carb setup can without going with a cam that requires a gear change. I'm sure they're out there.

 

[1969reddart]

Cam suggestions for a 360

 

[273]

Just keep it simple.

Near stock long block with 650 carb, 340 or similar cam and duals.

No point going over 9.1 cr and if running headers step up to comp xe262h cam.
If you can port that would be a bonus or EQ's

 

[rumblefish360]

hi

I am not confused.

You do that to me every time you reply with a freaking novel and that one was off topic in a big freakin way.

Answer the question!
The question asked!
Not with WHAT YOU THINK the answer should be.
Christ all mighty!

 

[rumblefish360]

Answering the original posters question!

3.23 gear and I'll assume a stock tire and to keep it cheap, stock torque converter though thats flexable...

218/@.050 intake duration
Exhaust can be the same but the split cams work well also.

Comp Lunati Crane all have a decent off the shelf cams that will work really good and at this duration, you can keep the stock converter or go for an additional 1,000 more rpms

 

[AJ/FormS]

Look, the stock cam puts the Dcr down in the basement at something like 6.85@125 psi, at 1300 ft as at Witchita KS. It already needs a loose TC and gears just to get out of it's own way........So almost any cam you put into it will just make the bottom end worse.
So now in goes the 218* which is maybe a 262/110advertised, and the ICA goes from 54* to 57*and the DCr goes to 6.5@122psi. So now the bottom end is even soggier. To get off the line will require maybe 2600 or a 2800 TC with those lazy 3.23s. And it will take off very little better than it does now with a 2250.Of course if she is currently saddled with a 1750ish TC, that 2800 would show a good improvement. But again, gains will be small as the rpm rises, and cylinder pressure keeps pace with it as the VE is rising;Until the torque peak is reached at maybe 3800rpm/34mph. From there to the Power-peak of maybe 5000, the new cam will make more power. How much? well considering the CI manifolds, and the low VE of the combo, I'll guess 20/25 hp tops. And 5000rpm is now 46mph.
But here's the deal; with the current 318TC, power will actually be considerably lower from take off to maybe break even at 2600/24 mph. So your ET from zero to 24mph will be slower. Then that 218 will start to make power, so that by 3800rpm/34 mph it will be making a bit more power . So somewhere between 24 and 34mph ET-breakeven will occur. I'll guess 28mph. Now that 218* with the 4bbls WOT will scream its way to 5500@50 mph.So, the ET from 28mph to 50 will be quicker, cuz those 20 peak hp are finally getting a workout.
For me, this situation would be completely unacceptable.I would just do the 2800TC first, and let the 2bbl stock-cam,360 spool up another 1000 rpm to be much closer to the torque peak.This will already be a good kick in the azz from zero to 34 mph, right where you want it; and that big 2bbl is good to about 34mph anyway.
The next step would be a free-flowing exhaust, to set yourself up for the 4bbl.
Next I would install the 4bbl, and get that to kick in as early as she'll take it. Baring wheelspin,the zero to 34mph-ET, with the 4bbl, is not gonna change much, but it's gonna sound like it. If you do get some wheelspin, then the ET may be noticeably reduced.
Once all that is done, then, THEN, she's ready for a small cam.
If you do the cam first, in that lo-Scr engine,you are just setting yourself up for disappointment. Been there done that.And so have many,many others, including some right here on FABO.
But I just gotta reiterate; With an 8.0 Scr, and a Dcr of 6.5@122psi (with a 262cam;[email protected]), this 360 is waaaaaaaaay below it's game. This 262/110 cam wants 10.0Scr to get a Dcr of [email protected] you will have a screaming quick engine.

 

[gregsdart]

From your comments, I would not go very big on cam, and keep the 3.21 gears, if that is what you have. Any deeper on the gear and high speed cruising will generate lots of rpm and more noise. Cam choice should be kept to something close to a stock 340 cam, or only a couple of degrees total duration more. A newer design cam will help performance, but I would be careful on selecting a cam that will have excellent street life; lobes with rate of lift that will last a long time similar to a stock cam. Premium pump gas and matching higher compression will help increase torque a bunch. Get the distributor recurved to bring in timing a bit earlier; be careful here, a mild cam needs less rate of advance than a bigger cam. Initial timing should be higher than stock, total advance shortened to match this change. Cold air to the carb and a 160 thermostat will help. A stock 318 high stall converter (if there are choices) would be my choice. Cheap and effective. Carb size sounds good, but I like a Thermoquad on a stock TQ manifold for great cheap power, or go Edelbrock RPM or similar. Be sure and learn about efficient exhaust systems. A great combo is very easily strangled by one seemingly minor mistake hear.

 

[Jakenks]

From your comments, I would not go very big on cam, and keep the 3.21 gears, if that is what you have. Any deeper on the gear and high speed cruising will generate lots of rpm and more noise. Cam choice should be kept to something close to a stock 340 cam, or only a couple of degrees total duration more. A newer design cam will help performance, but I would be careful on selecting a cam that will have excellent street life; lobes with rate of lift that will last a long time similar to a stock cam. Premium pump gas and matching higher compression will help increase torque a bunch. Get the distributor recurved to bring in timing a bit earlier; be careful here, a mild cam needs less rate of advance than a bigger cam. Initial timing should be higher than stock, total advance shortened to match this change. Cold air to the carb and a 160 thermostat will help. A stock 318 high stall converter (if there are choices) would be my choice. Cheap and effective. Carb size sounds good, but I like a Thermoquad on a stock TQ manifold for great cheap power, or go Edelbrock RPM or similar. Be sure and learn about efficient exhaust systems. A great combo is very easily strangled by one seemingly minor mistake hear.

All very good suggestions. Thanks. I am in contact with Oregon Cam Grinders regarding grinding me something similar to the 340 four speed cam or the auto cam, though I have found a Federal Mogul cam that is the same grind as the auto grind. The car has dual exhausts, exiting in front of the rear wheels, not a huge size, more rather similar to what was available in the 70s. Not certain if that will stay, but I'll experiment with that. The carb and manifold are things I have around the garage and since this is a low bucks set up, I think I'll try them. Most likely will add a one inch spacer to the mix to ensure that the secondaries open fully (because of teh plenum design).

 

[Jakenks]

That cam is by Speed Pro (part of Federal Mogul):
"Chrysler 318, 340 and 360 Hydraulic camshaft, 1500-4500 rpm range, 279 intake/ 290 exhaust adv. duration, duration @ .050 of 210 intake and 220 exhaust, Vavle lift of .429 intake and .442 exhaust, Lobe C/L is 114.

Matches Chrysler's 340 - 275 HP camshaft part# 2899206."

Chrysler 318,340,360 Hydraulic Camshaft by Speed Pro from Northern Auto Parts

 

[nm9stheham]

That cam is by Speed Pro (part of Federal Mogul):
"Chrysler 318, 340 and 360 Hydraulic camshaft, 1500-4500 rpm range, 279 intake/ 290 exhaust adv. duration, duration @ .050 of 210 intake and 220 exhaust, Vavle lift of .429 intake and .442 exhaust, Lobe C/L is 114.

Matches Chrysler's 340 - 275 HP camshaft part# 2899206."

Chrysler 318,340,360 Hydraulic Camshaft by Speed Pro from Northern Auto Parts

I personally would NOT go with that cam. That cam has too much advertised duration and slow ramps for your low compression 360. In fact, the large delta between advertised and .050" duration was no doubt done partly to make sure that the DCR of the 340 was not TOO high (to avoid detonation problems from bad gas and poor maintenance); the long advertised duration 'bled off' some of the dynamic CR.

The 340 static compression ratio was around 1.5 points higher than the 360 that you have, and so the 340 could handle the longer duration without the DCR going down into the toilet and the low RPM torque going with it. Low RPM torque will be important for your pure street cruising use, so I think the cam above is a mistake for how you describe the engine and car use.

Go with a newer, faster ramp cam and keep the advertised duration down around 262 or 256. Keep the lift down to .440" or so, so that you can use stock retainers (and even springs if you don't rev it very high). If you do want to rev it some, then get the manufacturer's matching set of springs. Single valve springs with dampers with around 100 lbs closed seat pressure or a bit more will do nicely.

I would like the 2nd smallest Lunati Voodoo cam for this: PN 10200701. Or a Crane H-260-2. Or Racer Brown EH-8. All are hydraulic flat tappet types. Comp XE has a similar grind. Install these cams either do-to-dot or even with a few more degrees of cam advance if you want even more low RPM grunt. (The above 2 cams come with 4-5 degrees cam advance already ground in. )

A new timing chain is a must, and getting something like the Mancini MRE262 set with the +/-4 degree crank sprockets is a decent deal that would allow you to set cam advance if you like. Make sure to measure and set the cam timing! 2 degrees change/error is noticeable; 4 degrees makes a significant change in engine behavior.