again 273 wanna hear your opinions ...

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pishta said:
what 'long tube headers' do you plan to run?
Click to expand...
they are "custom made" by a friend of mine which is running a Hot Rod-shop here in Germany.
unfort. i´ve never made a detailed pic of them ... but this pic from a race 2 years ago will give you an idea about the length :)

11728738_911272968931413_3725614574097520646_o.jpg
 
See my responses in red.

lilredridinghoo said:
again i´m into throwing a 273 together (as my wife complained that the fish was to rude and not really driveable in normal traffic with the beefed up Magnum motor)

Honestly, you should teach your wife how to drive, instead of band aiding the situation. It will serve her well in the future, and you'll not have to remove the Magnum. But it sounds like you've made your mind up, so read on.

so decision were made the Magnum has to go and i will stick it into my Dodge D100 Truck next year.

so here are my plans i wanted to hear your opinions on that

this is given and it should stay as it is (money wise)

273 .040over
318 Heads with compcams Springs 901-16, bowl blended, opened intake runners to 340size, bit of portwork, polished chamber and polished exhaust runners.

Don't even worry about the port work. For all the work involved, it's not going to net much. This isn't a race motor. You've said your "tuning down" from a Magnum engine. No need to "tune up" the 273, because it's such a small displacement, you'll not see porting benefits until past 5K RPM, IMO.

Stock converter, 904er with shift kit, 3,91 rear with 26inch tall tires
600 cfm Holley with Vac.Sec.
longetube headers unrestricted mufflers 2,5inch dual exhaust

oil pan - windage tray:

standard oil pan + windage tray
deep 8quart pan without windage tray
or deep 8quart pan + windage tray

No need for all the hoorah with the oil pan. You're not building a race engine, so the stock oiling system, including the pan is perfect!

camshaft - 340 HPstock cam: should i go 4 degrees advanced or not ? think it could/would give me a bit more fun on the low end

4*- 6* would be a good "guess". That's a sizable cam for a 273 on the street, so any bottom end torque you can come up with will help. I would CERTAINLY advance it, though.

intake: i do have an 360° offenhauser single plane and i also have a stock 340 4bbl-iron beast i would tend to use the offy, as it was on the motor when i bought the Barracuda years ago, but the runners are 318 size, which will be fine for the small motor (but the heads are allready opened up to match 340 gaskets, will it hurt too much using smaller intake on wider heads ? Guess the otherway around would create more turbolences ??)

The Offenhauser piece is a good one. Since you have it, use it.

thanks
Click to expand...
 
Good response RRR.
Another option would be, though "illegal", to tame the 360 and disguise it as 273. Or does TÜV actually check block numbers?

Edit: with TÜV being our DMV, sorta...
 
normally - they don´t have a look, but sometimes they do... the problem then will be (or in case of an accident) i get serious issues because the German TÜV will hand over a note to the German IRS and they will get me hooked for tax fraud and also the insurance company will try to get hands on me .... restrictions and law enforcement are getting tigther every year... some years ago no one took notice of an old american car.... but nowadays too many young idiots are out there doing illegal street racing etc, and also TV-shows with more and more Muscle-Car-Storys made the officials more attentive than 5 or 10 years ago.

btw... my wife is not a bad driver she´s not affraid of a fast car... it´s just the very rough behavior of the very light Barracuda compared with that high-reving (and very fast reving) Magnum engine.

and as i allready have the correct paperwork to put that Magnum Motor in my D100 Truck and beeing absolutely legal. At the moment there is only a 225 Slant in it which has a lot of work to do with 35x12,5 tires. Therefore the Magnum will be the better engine for the Truck

stixx said:
Good response RRR.
Another option would be, though "illegal", to tame the 360 and disguise it as 273. Or does TÜV actually check block numbers?

Edit: with TÜV being our DMV, sorta...
Click to expand...
 
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Talking about solid lifter cams,Here is why I said that I would get one; The solids have faster rate clearance ramps. This allows you to install one size bigger cam, without the cylinder pressure loss, usually associated with that amount of.050 duration
Another way to look at it is;with the same advertised,you can have the next larger sized .050

Here is an example, purely hypothetical;
a 262/268/110 cam, might have, as a
FTH ,216/[email protected]. But same cam as a solid, might have
Solid 224/229.. That's a difference of 8/7,
and one cam size is generally considered to be 7*
________________________________________
Now from the other side, if you wanted a 216/222 cam, a FTH might be 262/268. But the solid might be 255/261, again 1 size difference. Now, because the ..050s are same, they make very similar absolute power. But the advertised numbers will affect the idle, the fuel consumption,and the Part Throttle performance.

To get a sense of that 262 vs 255, let's install these two, in the same 273 with no other changes, again at split-overlap, and lets make them 110LSAs. And I'm just gonna capture the important numbers from the Wallace Calculator, as; Scr/Dcr/Psi/VP.
>So with the FTH, I get;
8.0/6.62/125/82 This would be very weak.But with more Scr, I get
9.6/7.90/157/104 And still more
9.9/8.14/163/108 Here the pressure is maxed out for 95Ron, and you might have to run 98 for WOT work. So this is as good as it gets with a FTH.
> Next ,the solid; I get;
8.0/6.79/129/88 Again , weak, but better than with the FTH
9.6/8.11/163/111 About as good as it gets
9.9/8.36/169/115 Too much pressure now,for available fuel!
So now look at the Scrs, where the pressure is maxed out at 163psi. Notice the numbers are 9.9 for the FTH and 9.6 for the Solid.
If your 273 came in at 9.6Scr, and you installed the FTH, you would be sacrificing 6psi and more importantly 111/104= a loss of 6.7% in VP, and that's a heavy loss for a 273.
But if your Scr came in at 9.9 you couldn't even run an
equivalent-at-.050 solid, because the pressure would be too high.
___________________________________________________
Ok so lets say you have decided that a solid is the way to go. Let's talk about LSA. Say you like the 216/222 cam. You could theoretically get that on any LSA from about 115 down to 102. That's about 2 cam sizes or peak power difference of 400rpm.But let's see what happens to the pressure. Again at split-overlaps.

The solid, above, was a 110, as were all of those,so copy/paste
9.6/8.11/163/111 About as good as it gets
9.6/7.85/156/102 This is at 115LSA, and
9.6/8.50/173/124 this is at 102LSA
Notice that all are at 9.6Scr. But look at the pressure differences from 156 to 173. So you can see that the pressure needs to be sorted out for each cam. Notice also the VPs from 102 to 124! that would be the difference from a loser combo at 102, to barn stormer at 124.
So lets reset the pressures to about 163 and see what happens., I get
9.9/8.09/162/106 with the 115...................loser, but mellow for Mrs.Red
9.6/8.11/163/111 About as good as it gets, and
9.2/8.15/164/118 with the 102...............winner for you
Check it out, 118 is now 3 units higher than the stock 273 with the optimized cylinder pressure, So finally the bottom end is now at least no weaker than stock. But the power has moved way up in the rev range, to make use of those 3.91s and the OVERLAP has increased from 20* with the 240/112 cam, all the way to 54* with this 255/102 cam.

but wait, the VP is now 3 units higher. Hmmmmmmmm, you could move up one more cam size, and top up the Scr and .......oh never mind lol, it's for Mrs.Red......right? lol
Ok wait, I had to see
9.3/8.16/164/117, This with 258/264/102 in at 101, and now 57* of overlap, so power peak moved up again a wee bit.And with the Rpm came a few more ponies.
but wait, the VP is still greater than 115,the stock optimized 273. Hmmmmm
9.25/8.12/163/116, with a 262/268/102 in at 101,for 61* of o/lap,and more rpm
Oh, Gee, room for one more,lol
9.55/8.17/164/113,with a 266/272/102, in at 101, for 65* O/lap, and more rpm
Doh,
Plug that into your desk-top dyno! woodgha
 
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AJ/FormS said:
Talking about solid lifter cams

Here is why I said that ; The solids have faster rate clearance ramps. This allows you to install one size bigger cam, without the cylinder pressure loss, usually associated with that amount of.050 duration
Another way to look at it is;with the same advertised,you can have the next larger sized .050

Here is an example, purely hypothetical;
a 262/268/110 cam, might have, as a FTH ,216/[email protected]. But same cam as a solid, might have 224/229.. That's a difference of 8/7, and one cam size is generally considered to be 7*
________________________________________
Now from the other side, if you wanted a 216/222 cam, a FTH might be 262/268. But the solid might be 255/261, again 1 size difference.

To get a sense of that 262 vs 255, let's install these two, in the same 273 with no other changes, again at split-overlap, and lets make them 110LSAs. And I'm just gonna capture the important numbers from the Wallace Calculator, as; Scr/Dcr/Psi/VP.
>So with the FTH, I get;
8.0/6.62/125/82 This would be very weak.But with more Scr, I get
9.6/7.90/157/104 And still more
9.9/8.14/163/108 Here the pressure is maxed out for 95Ron, and you might have to run 98 for WOT work. So this is as good as it gets with a FTH.
> Next ,the solid; I get;
8.0/6.79/129/88 Again , weak, but better than with the FTH
9.6/8.11/163/111 About as good as it gets
9.9/8.36/169/115 Too much pressure now,for available fuel!
So now look at the Scrs, where the pressure is maxed out at 163psi. Notice the numbers are 9.9 for the FTH and 9.6 for the Solid.
If your 273 came in at 9.6Scr, and you installed the FTH, you would be sacrificing 6psi and more importantly 111/104= a loss of 6.7% in VP, and that's a heavy loss for a 273.
But if your Scr came in at 9.9 you couldn't even run an
equivalent-at-.050 solid, because the pressure would be too high.
Click to expand...

How about a Isky E-4? My 273 had 9.68 static compression and the E-4 specs are as follows. .425 lift 260/260° 216/216° @.050. 108° lobe center.
 
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All this dynamic compression stuff is giving me a headache. LOL. The Comp 270S is lopey but very tame in a low compression 318 I am running in my short-box A-833 O/D truck these days. 224*@.050", 110LSA, .468" lift. I run the lash at .018/.022" hot but you could open it up to .028/.032" if it was too rough idling in a 273. That E-4 Isky would be a sure-fire stable idle with some authority, but not very choppy. A friend has one in a similar 318 to mine and it's stocker-smooth when warm, idling.
 
Bighead440 said:
All this dynamic compression stuff is giving me a headache. LOL. The Comp 270S is lopey but very tame in a low compression 318 I am running in my short-box A-833 O/D truck these days. 224*@.050", 110LSA, .468" lift. I run the lash at .018/.022" hot but you could open it up to .028/.032" if it was too rough idling in a 273. That E-4 Isky would be a sure-fire stable idle with some authority, but not very choppy. A friend has one in a similar 318 to mine and it's stocker-smooth when warm, idling.
Click to expand...
Yep!
 
Yepp, it causes headache ... but i think i got thepoint behind it... Unfortunately it's very complex to do those calculations and AJ/FormS deserves my greatest respect.
Thanks foor showing me that the 340 cam wouldn't fit.
Maybe i will simply take the 318 stock cam but it would also be interested to know the results for the SSI11309 cam. But calculation will not work as i only have duration LSA and lift.
 
toolmanmike said:
How about a Isky E-4? My 273 had 9.68 static compression and the E-4 specs are as follows. .425 lift 260/260° 216/216° @.050. 108° lobe center.
Click to expand...

In at split overlap(44*),or 108* for an ICA of 58*
Static compression ratio of 9.68:1.
Your dynamic compression ratio is 8.07:1 .
Your dynamic cranking pressure is 161.70 PSI.
V/P (Volume to Pressure Index) is 108...................... 108 ..
On the money Mike

In at 106, for an ICA of 56*. 2* advanced
Static compression ratio of 9.68:1.
Your dynamic compression ratio is 8.17:1 .
Your dynamic cranking pressure is 164.30 PSI.
V/P (Volume to Pressure Index) is 112 ........................112 ..
They say 165psi is about the max pressure for pump gas, so this looks about as good as it gets for this combo.This is a single-pattern cam, so to take max advantage of that smallish overlap, she wants to be close to straight up, so in at 106 is perfect. Good job man!


In 4* advanced at 104*,for a ICA of 54*
Static compression ratio of 9.68:1.
Your dynamic compression ratio is 8.28:1 .
Your dynamic cranking pressure is 167.18 PSI.
V/P (Volume to Pressure Index) is 115...................... 115 ..
Probably too much for pump gas

This E-4 cam has 44* of overlap, just like the 340 cam. But unlike the 340 cam; in at 106, it has 120* of extraction, so in steady-state point to point traveling, it should get pretty good fuel mileage. Spec wise, it's almost identical to the 360 2bbl cam, but with 8* more intake duration, and the new LSA gives it 44* overlap, to the 32* of the 360. So with headers working that 44*, it should bring a nice bump in power once wound up.

Here they are side by side;
..................int/ exh/psi/ pwr/Lsa/0-lap/install
1) the E-4; 260/260,124/120/108/44 in at 106
2) 360-2v; 252/260/122/118/112/32 in at 112
3) 340-4v; 268/276/114/106/114/44 in at 112
4) custom; 268/276/122/114/106/60 in at 104
You see that 106 extraction,of the 340 cam? that's mostly why this cam sucks gas.You see that custom#4 cam,It's the same 340 cam but with the LSA closed up to 106LSA.Now the extraction is up to 114,getting close to the 360-2v's 118, and we mostly all know what to expect from the 360 cam.
And the E-4 has another couple of degrees of extraction.
 
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lilredridinghoo said:
Yepp, it causes headache ... but i think i got thepoint behind it... Unfortunately it's very complex to do those calculations and AJ/FormS deserves my greatest respect.
Thanks foor showing me that the 340 cam wouldn't fit.
Maybe i will simply take the 318 stock cam but it would also be interested to know the results for the SSI11309 cam. But calculation will not work as i only have duration LSA and lift.
Click to expand...
That's all the Wallace Calculator needs. Sock-it-to-me. All I do is punch the numbers in, and try to interpret the results.
 
AJ/FormS said:
In at split overlap(44*), for an ICA of 58*
Static compression ratio of 9.68:1.
Your dynamic compression ratio is 8.07:1 .
Your dynamic cranking pressure is 161.70 PSI.
V/P (Volume to Pressure Index) is 108...................... 108 ..
On the money Mike

In 4* advanced at 104*,for a ICA of 54*
Static compression ratio of 9.68:1.
Your dynamic compression ratio is 8.28:1 .
Your dynamic cranking pressure is 167.18 PSI.
V/P (Volume to Pressure Index) is 115...................... 115 ..
Probably too much for pump gas
Click to expand...
Yes, I did advance it a couple degrees. I usually run 92 octane non alcohol Premium with no issues. I have ran 87 but I didn't hot rod it. The shop that did the heads polished the chambers which may help. Those closed chamber 273 heads are pretty efficient with a little work. Thanks for the update.
11_14_0.JPEG
041600951718[01].jpg
041600951719[00].jpg
 
Another thing that seems to help is tight-Q. I have successfully run as little as .028 with hypers and aluminum heads, at a minimum cooling system temp of 205*F, and a free-flowing exhaust. My latest combo has run .034,since 2004, about 100,000 miles.
 
Sorry to hi-jack this post but...what are the current specs on your car and engine A J?
 
ir3333 said:
Sorry to hi-jack this post but...what are the current specs on your car and engine A J?
Click to expand...
Well it's a 367 with KB107s. It's been decked to get 10.9Scr and .005 pop-up for .034 Q with .039gaskets.She's got a Milodon 7qt roadrace pan with their tray and pick-up, that I run just 5 qts in.
Heads are OOTB aluminum Eddies,with Hughes springs 1110s IIRC, which I shimmed up a tad to get 7200 out of her.
The cam is an old Hughes HE 3038AL FTH with specs of 276/286/110 and .050s of 230/237.. and Mopar 1.6rollertipped only arms for lifts of .549/.571. and 1/2 turn lifter preload.Well they were,lol. There's a couple of tickers in there now.
I run her at 205*F, a hi-flo system and a Thermostatic clutch on a 7-blade hi-attack steel fan.
I run fresh cold air straight down thru the hood-mounted filter,no scoop,thru the 750 DP,and into the AG .
She runs TTIs and their full-length dual 3inch mandrel-bent pipes,thru Dynomax 3-pass muffs, no crossover.
I run a 3.09low-A833 with a GVOD behind it, that I use as a splitter, and 3.55s out back.

Currently I'm running
Static compression ratio of 10.9:1.
Your dynamic compression ratio is 8.72:1 .
Your dynamic cranking pressure is 178.73 PSI.
V/P (Volume to Pressure Index) is 153

Combo has gone 93 in the 1/8th.

This same combo has run the 292/108/508lift cam with an Scr of 11.3
And also run a Hughes HE 2430AL, also at 10.9 Scr.
This one ran at;
Static compression ratio of 10.9:1.
Your dynamic compression ratio is 8.96:1 .
Your dynamic cranking pressure is 185.09 PSI.
V/P (Volume to Pressure Index) is 164 .
This was my favorite.... because of the BB-like torque, and the phenomenal fuel-mileage it made. This was my DD for 4 or more years. A 164VP is very powerful at low rpm
 
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Bighead440 said:
All this dynamic compression stuff is giving me a headache. LOL. The Comp 270S is lopey but very tame in a low compression 318 I am running in my short-box A-833 O/D truck these days. 224*@.050", 110LSA, .468" lift. I run the lash at .018/.022" hot but you could open it up to .028/.032" if it was too rough idling in a 273. That E-4 Isky would be a sure-fire stable idle with some authority, but not very choppy. A friend has one in a similar 318 to mine and it's stocker-smooth when warm, idling.
Click to expand...

Now you see what I'm up against. Nobody listens to experience. It's "what's this calculator say"? Rather than listen to someone whose put together so many engines that they can make a better recommendation than any calculator ever could. Talk about a headache alright.
 
OMG! AJ! Relax!

My Saxon friend, IMO, for an excellent driver, use the 318 cam. Mildly warmed up, as in barley noticeable, the 360 cam.
I myself would do the 360 cam.
 
I’m old school and have used the 340 cam many times with good results in 273-318s. The power was there, but the gas mileage was a little lacking. I ran 3.23 and 3.55 gears with a P245/60R14 rear tire. Used a stock 340 converter in a built 727. Most of the time 14-18 mpg. Of course that was when gas was cheap. Kim
 
We put that exact cam (270S) in the 273. Too big (imo). Love the sound blah blah blah but engine is coming out and another small block
Bighead440 said:
All this dynamic compression stuff is giving me a headache. LOL. The Comp 270S is lopey but very tame in a low compression 318 I am running in my short-box A-833 O/D truck these days. 224*@.050", 110LSA, .468" lift. I run the lash at .018/.022" hot but you could open it up to .028/.032" if it was too rough idling in a 273. That E-4 Isky would be a sure-fire stable idle with some authority, but not very choppy. A friend has one in a similar 318 to mine and it's stocker-smooth when warm, idling.
Click to expand...
going in. Pending tc and gear choice( I'm running 323) you could be disappointed.
 
Something different just creeped into my mind. .. anyone ever used a 318 hughes whiplashcam in a 273?

Just wrote Hughes Engines, whether it would work ( waiting for an answer from them now )
 
It will work if you make it work. Correct springs, You may need to machine the valve guides for clearance with that lift. And don't forget valve to piston clearance. You will need a converter and like they recommend at least a 3:55 gear. It won't have much vacuum (If you have poser brakes) and it will idle like a top fueler. It is not necessarily a mild cam for a 318. It will be rougher in a 273. Because it's hydraulic you will need the correct pushrods and I would recommend adjustable rockers.
 
I just put an XE262 in a 273 I am working on. Runs great, at least on the stand. Idles at 650, really snappy with no load, 901-16 springs, Comp off-the-shelf pushrods. The whole cam package was under $340 and no machining required.
here are times to really science out a combination. But for a car that is being detuned this is being way overthought. Way WAY overthinking in some cases. My $.02 anyway.
 
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