Combination for a peppy 340

[1MeanA]

The '68 4 speed cam is less than $200 but Oregon can grind you anything you want. Your cam choice will be limited by compression.

 

[junkyardhero]

Hoping that’s all of needs.. rings, bearings, polish the crank.. but if it needs more than a hone, I’d put some .040 over KB pistons in it. It should have a healthy level of compression while running in 93.

leave it at the discretion of your machinist, but ALWAYS take the least amount possible.

caveat: unless 20 over pistons are prohibitively expensive for the application or whatever.

 

[FlamesAreWicked]

leave it at the discretion of your machinist, but ALWAYS take the least amount possible.

caveat: unless 20 over pistons are prohibitively expensive for the application or whatever.

Once they take some measurements for size and taper, then we can figure what the course of action will be. Many have told me a good hone and rings should do the trick. I’m just not banking on being that lucky lol. If so, even better. Since it’s already .030 over, if a hone doesn’t take care of it, hopefully another .010 bigger would.

 

[autoxcuda]

So this was a complete assembled motor? Was it run before? Was that 484 cam in it and broken in?

Careful of the machinist. They get paid to "machine" stuff. From the few pictures posted it looks really clean. A .002 ridge/taper or even less... just run it. I've had machinist say, it may puff some smoke at WOT. For a motor with hardly any ridge at the top on thrust areas only. Looking back, should not have rebuilt it.

 

[FlamesAreWicked]

So this was a complete assembled motor? Was it run before? Was that 484 cam in it and broken in?

Careful of the machinist. They get paid to "machine" stuff. From the few pictures posted it looks really clean. A .002 ridge/taper or even less... just run it. I've had machinist say, it may puff some smoke at WOT. For a motor with hardly any ridge at the top on thrust areas only. Looking back, should not have rebuilt it.

It was an assembled running long block. When the intake was pulled, some moisture gotten into a couple of cylinders. Prior to my purchase and unbeknownst to the seller. Not catastrophic but it will need some work. The seller did give a sizable amount back due to the unforeseen state of it. The engine builder will tear it down, get what machine work it needs done at the machine shop, and it’ll get new rings and bearings at a minimum. If the measurements check out that a hone will bring it back then fine. If not, then possibly opening it up from .030 over to .040 over may be on the table. The cam I measured was in the engine when I bought it and is well broken in. I didn’t buy a freshly rebuilt engine with no run time. It came out of a running and driving car. This whole chain of events was unexpected and I’m trying to make the most of it.

 

[RustyRatRod]

Careful of the machinist. They get paid to "machine" stuff.

That's the God's truth right there.

 

[crackedback]

If the cam is the hyd 484 on 108, keep it. If it is the 114 doorstop pile o'**** unit, get a different camshaft. Depending on final compression, put that 108 cam in anywhere from 100-104 and run the snot out of it.

You have a 4 speed car so in gear drag is not an issue.

If you can bust out a die grinder, blend/clean up the bowls/short turn if doing machine work to the heads.

Air gap and a good 750 carb, headers, good ignition curve and it will sound great and be a solid low 12, maybe high 11 second engine in a good chassis.

JMO

 

[fishmens67]

As usual, people make things way harder than they have to be. Mopar had an easy recipe for this and it was a screamer.

That was then, this is now.
a stock 340 is a tame mouse in today's world, the 318 of yesteryear.

 

[RustyRatRod]

That was then, this is now.
a stock 340 is a tame mouse in today's world, the 318 of yesteryear.

No. It was a 340 then and it's still a 340.

 

[autoxcuda]

That was then, this is now.
a stock 340 is a tame mouse in today's world, the 318 of yesteryear.

There's some truth to that. 300 hp or even modified to 400hp isn't what it used to be.

2015-2024 Hemi auto Challengers post 13.7 1/4mi times. I daily commute 66 miles round trip in one.

 

[RustyRatRod]

When it comes to wants and needs.. the lines can be blurred quickly. I’m sure the stock 68 340 4spd cam is a great piece. I don’t have any interest in using one.

People do indeed love to spend your money for you.. and this isn’t exclusive to the car community. A fun street car can be interpreted many ways. It can vary person to person considerably. Some people’s idea of a fun street car is a 800hp+ late model mustang/challenger/camaro. Other people may see a 140hp Miata as one.. neither route is wrong..

When I used to be up to my eye balls in guitars and amps.. people would talk about buying the nicest of custom shop guitars priced in $8k-10k range and beyond and own several. $10k guitar amp that would be loud enough for the stage at Woodstock and have a wall of them. Yet they played in their garage or basement. They’re not in a band and they don’t get paid to play.

While I won’t be living at the track with this thing, it will get used for more than idling through the local cars and coffee meet. It won’t be as egregious a Lambo owner who only takes their car out to the local starbucks 2-3 times a year but I digress

Guess we’ll just see how this combo works.

Spend your money? You did come here asking about a "peppy 340 combo", right? Certainly you're not expecting to get it done for free. A reground cam has several advantages including cost and the fact that Chrysler cam cores are hardened to the core, so rehardening isn't necessary. Good luck with whatever you choose, but don't complain about people "spending your money" when that's exactly what you asked for.

 

[RustyRatRod]

If the cam is the hyd 484 on 108, keep it. If it is the 114 doorstop pile o'**** unit, get a different camshaft. Depending on final compression, put that 108 cam in anywhere from 100-104 and run the snot out of it.

You have a 4 speed car so in gear drag is not an issue.

If you can bust out a die grinder, blend/clean up the bowls/short turn if doing machine work to the heads.

Air gap and a good 750 carb, headers, good ignition curve and it will sound great and be a solid low 12, maybe high 11 second engine in a good chassis.

JMO

Don'tchya hold back now. lol

 

[James Clews]

Back in the seventies I had a 340 with 11.5 comp (forged pistons) with the mopar performance 292/510 cam in it and it idled really nice with a six pack induction. It would pull down low in second gear from about 600rpm with the accelerator flat down and just pull away until the secondaries came in with an almighty rush! fast forward to about 2010 and I built my 410 stroker and used that 292 510 style cam and I hated it. That thing didn't really smooth out until about 2500 rpm. What was the difference?
The 1970s cam was on a 114 lobe centre and the new one was on a 106 centre line.
I took that cam out and rebuilt my motor with a custom grind hyd roller 238/241 @ fifty on a 112 c/line.
My car is a really nice car now and runs low elevens @ 120mph and does not buck and jump about with my 5 speed manual transmission and is really good on fuel, returning 23 mpg on a run. so to say that 114 centreline cam is a piece of crap alarms me because not everyone likes a car that behaves really badly until the revs get up, some of us want not only a car that performs but is also pleasant to drive and live with!

 

[crackedback]

Back in the seventies I had a 340 with 11.5 comp (forged pistons) with the mopar performance 292/510 cam in it and it idled really nice with a six pack induction. It would pull down low in second gear from about 600rpm with the accelerator flat down and just pull away until the secondaries came in with an almighty rush! fast forward to about 2010 and I built my 410 stroker and used that 292 510 style cam and I hated it. That thing didn't really smooth out until about 2500 rpm. What was the difference?
The 1970s cam was on a 114 lobe centre and the new one was on a 106 centre line.
I took that cam out and rebuilt my motor with a custom grind hyd roller 238/241 @ fifty on a 112 c/line.
My car is a really nice car now and runs low elevens @ 120mph and does not buck and jump about with my 5 speed manual transmission and is really good on fuel, returning 23 mpg on a run. so to say that 114 centreline cam is a piece of crap alarms me because not everyone likes a car that behaves really badly until the revs get up, some of us want not only a car that performs but is also pleasant to drive and live wi

11.5 and a 114 might work. that 114 cam is garbage IMO in a true stock 9.7 compression 340.

Put the wider in a stroker, fine... inches eat up the 112-114.

What's the OP got... not 11.5:1 Carry on

 

[FlamesAreWicked]

Spend your money? You did come here asking about a "peppy 340 combo", right? Certainly you're not expecting to get it done for free. A reground cam has several advantages including cost and the fact that Chrysler cam cores are hardened to the core, so rehardening isn't necessary. Good luck with whatever you choose, but don't complain about people "spending your money" when that's exactly what you asked

I was sharing what my plans were and I had two cams in mind that I was considering. I did ask about lifter manufacturers but, no, I wasn’t asking for people to spend money for me.

 

[Dartswinger70]

Does anyone know the deal at Oregon cams? I sent a core to them they said it no good then said they can sell me one I sent $$$ info and haven't heard anything am I supposed to call or will they call me?

 

[Illahe]

Some may know I picked up a 71 340 for my 68 Dart. It’s at the engine shop to be gone through. While trying to avoid the snowball effect I’m looking at some parts I may upgrade to “while I’m at it”. It’s a slippery slope. It currently has 587 J heads and I measured it having 2.02 intake valves. It’s .030 with silvolite 68-72 pistons. Also roughly measured it having a .484 lift cam. Talking about it with the engine guy, if I keep the stock heads, I could, if not definitely, be looking at some cost to refresh them. It got me thinking that it would be an opportunity (or excuse lol) to step up to the Edelbrock 60175 340 heads. They’re 65cc and made for a hydraulic roller cam. Also I was looking at a Howards hydraulic roller cam.. there’s two I’ve been looking at. I have 3.55 gear and a 4spd. Rpm air gap intake will be used and a Holley 670 avenger carb. Doug’s headers will also be used.

First one is .235/.243 @ .050 with .530/.530 lift on a 109, 2000-5700 rpm range

Second one is .243/.251 @ .050 with a .530/.515 lift on a 109, 2400-6000 rpm range

I think the little difference between the two comes down to the rpm range you prefer.. the first one being more ideal overall. 340s can spin but I’m not much of a track goer anymore.

Intended use is a fun street car. I live out in the boondocks so any sort of city driving will be in podunk towns around here. Car shows, cars n coffee, and cruise nights sprinkled in there.

I plan to use morel roller lifters as I think it’s basically what Hughes sells and they look the same as what Howard’s uses.. anyone know from experience if they’re the same? Or just buy the morel ones specifically?.. the carb will be a little small for optimum potential but I have it and I thought I’d use it. Ought to be a world of difference from the stock 318 and BBD setup lol

TF heads are the ones to have but they are more expensive and I wouldn’t be utilizing their full potential anyhow. If ever it sees the strip, it’ll be just to see what it can do for shiz and giggles. Anyhow, I look forward to having in the car by the time the Louisiana blaze has given us a break for the year.

Call Kevin at Schneider Cams, and run a SFT. The Howards SFT 238*/238* .558 on 108 lsa in a 9:1 360 69 4spd Dart with 3.55:1 and 275/60/15. Went 14.3 at 101.3 blazing the tires out of the hole. Stock heads are done under .5" lift, and the cam was done at 5400. Get some area under the curve with a SFT.

 

[mopowers]

Does anyone know the deal at Oregon cams? I sent a core to them they said it no good then said they can sell me one I sent $$$ info and haven't heard anything am I supposed to call or will they call me?

I bet you'd get better information by calling them vs posting a question about it online. I've always had good luck calling them during business hours.

 

[Dartswinger70]

I bet you'd get better information by calling them vs posting a question about it online. I've always had good luck calling them during business hours.

Yeah I know I just don't wan to be that PITA customer / guy I gave then my payment info I figured they'd let me know when it ships etc. Ill call before too long I think its going on 6 weeks or so.

 

[mopowers]

Yeah I know I just don't wan to be that PITA customer / guy I gave then my payment info I figured they'd let me know when it ships etc. Ill call before too long I think its going on 6 weeks or so.

I hear ya. No one wants to be that annoying customer. But after 6 weeks, I'd have no problem giving them a call to check status. They'll be happy to help ya out. Who knows, maybe there was a misunderstanding or something and they are waiting on you for the green light.

 

[LO23M8B]

Build it stone stock with the four speed cam and headers. Done.

With a rod upgrade and a full 10.5 to 1.

 

[AJ/FormS]

I have a 360 with closed chamber heads, and factory 318/bushed rods. My pistons are .007 pop-up, and I run the FelPro 039, for a Q of .032. I have run as low as 028.
With Alloy heads I have run up to 195 psi, cylinder pressure, still on 87E10.
I currently run a 230/237/110 cam, But, I liked the previous 223/230/110 cam way better, and it gave me gangbuster fuel-economy. I've been waiting almost 20 years for this cam to give up, but it's like the Energizer Bunny, it just keeps going and going.

The point I am trying to make here is to not let SCR scare you with alloy heads. I have run as high as 11.3 with no detonation on 87E10, which is all this engine has ever run.
My guess is that for a streeter, every 15 or so psi is worth at least one cam size in top-end power. Ergo, with 195 psi, you can drop at least one maybe two cam sizes, over what you had to run at 165.
What this means for a streeter is that you can set your car up to be super torquey with 3.23s, and maybe less gear, and still have a car that goes 106 in the quarter, likely in the 12s.
I mean, My combo proves it.
With a manual trans, the advantage of bottom-end torque means that once in Second gear, you can pretty much leave it there, all day.

If yur running hypers, I highly recommend that you do some research as to ring-gaps. I put mine in at a factor of .0065 per the instructions, which was .026inch.
I had nothing but overheating issues that summer which I could not solve in the usual ways. That winter, I pulled the engine out, tore it down, and replaced the rings, This time I used ring-factors of 0085 Top, and .0075 Second; which was .034 top/.030 Second. I left the oil-ring alone.
That solved the overheat.

 

[LO23M8B]

I have a 360 with closed chamber heads, and factory 318/bushed rods. My pistons are .007 pop-up, and I run the FelPro 039, for a Q of .032. I have run as low as 028.
With Alloy heads I have run up to 195 psi, cylinder pressure, still on 87E10.
I currently run a 230/237/110 cam, But, I liked the previous 223/230/110 cam way better, and it gave me gangbuster fuel-economy. I've been waiting almost 20 years for this cam to give up, but it's like the Energizer Bunny, it just keeps going and going.

The point I am trying to make here is to not let SCR scare you with alloy heads. I have run as high as 11.3 with no detonation on 87E10, which is all this engine has ever run.
My guess is that for a streeter, every 15 or so psi is worth at least one cam size in top-end power. Ergo, with 195 psi, you can drop at least one maybe two cam sizes, over what you had to run at 165.
What this means for a streeter is that you can set your car up to be super torquey with 3.23s, and maybe less gear, and still have a car that goes 106 in the quarter, likely in the 12s.
I mean, My combo proves it.
With a manual trans, the advantage of bottom-end torque means that once in Second gear, you can pretty much leave it there, all day.

If yur running hypers, I highly recommend that you do some research as to ring-gaps. I put mine in at a factor of .0065 per the instructions, which was .026inch.
I had nothing but overheating issues that summer which I could not solve in the usual ways. That winter, I pulled the engine out, tore it down, and replaced the rings, This time I used ring-factors of 0085 Top, and .0075 Second; which was .034 top/.030 Second. I left the oil-ring alone.
That solved the overheat.

Were ring ends butting?

 

[AJ/FormS]

Were ring ends butting?

Now that's a really really great question.
That was winter of 2000/2001, and
I can't actually remember looking anymore.
I just went straight to file-fitting the new rings, and afterwards
the engine actually ran too cool. ........ so I assumed, I had been right.
My plan was to go look at the rings later, but I can't actually remember doing that.
Dang good question.
I think I kept the rings; I can't recall ever throwing them away. I guess I aughtta go find them and look!
My bad.
I'll be back,...........

 

[RustyRatRod]

With a rod upgrade and a full 10.5 to 1.

Why? To waste money? No need for different rods.