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Author Topic: 361  (Read 2522 times)

Jason Goldsack

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« Reply #15 on: January 23, 2011, 04:13:07 AM »

Anyone have any luck with the MP porting templates that are sold... I could use them on the 516's...

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Jason

(Eileen)1965 Chrysler Windsor, 361/727/2.76 16.49 @ 86 mph

Steve

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« Reply #16 on: January 23, 2011, 07:31:10 AM »

Jason. . .Read over the thread in engine tech about modifying a small block.
http://www.moparfins.com/forum/forum_posts.asp?TID=3069
 
POLARACO2011-01-23 12:31:46
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Jason Goldsack

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« Reply #17 on: January 23, 2011, 09:21:55 AM »

ok

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Jason

(Eileen)1965 Chrysler Windsor, 361/727/2.76 16.49 @ 86 mph

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« Reply #18 on: January 23, 2011, 11:56:57 AM »

http://www.moparmusclemagazine.com/techarticles/engine_challenge/mopp_1005_2009_amsoil_mopar_muscle_engine_challenge_laroy_engines_promax_performance/photo_12.html
 
Here is a perfect picture to show what a combustion chamber of a closed chamber should look like. This is the LaRoy engine that made 723hp out of a 451 stroker 400, more than 1.6hp per cubic inch, and only 1hp less than the winner with a 500cubic inch stroker, but look at how clean this chamber is and then tell me that lip is a good thing.
 
http://www.moparmusclemagazine.com/techarticles/engine_challenge/mopp_1103_amsoil_mopar_2010_engine_challenge_dyno_contest/photo_16.html
 
Look at the pistons and combustion chambers of these small block heads, you will see grunge and clean spots, including some "washing" on the surfaces, tons of work to fix this problem, but well worth the effort. It is an example of what the flow problem is, and what it takes to fix, and the results are more than worth the time. We are talking these engines could show greater than 50hp/lb-ft increases just by fixing these little problems. And the smog numbers go down, not up, and mileage will go up, not down. How can one argue with that?
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Steve

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« Reply #19 on: January 23, 2011, 02:55:10 PM »

Ed   You totally lost me with that  The head doesn't look like anything was done to it
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Jason Goldsack

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« Reply #20 on: January 23, 2011, 03:29:33 PM »

I think I better worry about fixing the leaf springs, put some gear in it and put the HP Manifolds on it first..

Started right up this morning.. no choke....it was -22 C ...


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Jason

(Eileen)1965 Chrysler Windsor, 361/727/2.76 16.49 @ 86 mph

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« Reply #21 on: January 23, 2011, 04:26:10 PM »

Quote from: POLARACO
Ed   You totally lost me with that  The head doesn't look like anything was done to it

The small block heads that are clean are not touched at all. The LaRoy article and the couple chamber pictures you can see the "edging" at the middle of the cylinder, which is a sharp raised lip,  when not removed does some major restriction that has consequences with flow and burn. With the lip removed you can see the metal that was removed because it will remain looking like that for a million miles, and you can see the flame/burn pattern goes over about 95percent of the combustion chamber itself, and it will remain as clean as it is in the picture forever because the burn is better, as in more efficient.
 
 
Here is the back side, meaning the piston with a raised dome. Notice the clean edge at the top, notice the garbage on the back side and notice the outside edge is clean. This is basically a reverse of the combustion chamber and it is not right. This is one reason I don't like domed pistons, but there is the ability to fix this as well to reduce the garbage carbon build-up, which is fuel that is burning but at a much lower compression ratio and after the piston is down in the bore, which is a total waste of using a dome to increase compression. If the raised dome is rounded so the flame can travel around the top of the dome and keep burning at a higher compression, the piston would be cleaner, much more power would be made, and the efficiency would go up, and it can run on lower octane without a problem (higher octane produces more power, just like engines used to when running higher octane, you used to notice the difference, now you don't) not down, which is why the higher compression engines run better at higher rpm vice lower rpm.  This is an extreme example inside a 3.3 CanAm Mopar engine, one of 50 produced at the inception of the 3.3 (early 80s I believe), so this 300hp engine could actually produce more than 375hp and an increase of torque if it were done correctly.
 
Send pictures of combustion chambers, any chamber, and I will describe what needs to be done to fix the chamber or piston to make it more efficient. Remember, most engines are described at about a 65percent efficiency, which is sad when it takes so little to get them into the 85-95percent efficiency range.
 
dana442011-01-23 21:39:19
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Steve

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« Reply #22 on: January 23, 2011, 05:03:10 PM »

I think I know where you are talking about. . .   But that was not the case on those 65 heads
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« Reply #23 on: January 23, 2011, 05:28:27 PM »

Are you saying the '65  heads were open chamber heads? There is still a lip on all the closed chamber heads. Ford, Chevy small block, all of them with the exception of the early Hemi heads (the 426 can gain out of piston edging/massaging), the rest of the Hemi heads are all sealing head gasket problems as I recall, and the new Hemi 5.7 etc., has this same chamber problem on them ( the sparkplug pockets in the head throw the flame to the opposite plug and that is wrong, there is still quench edges that need to be rounded or "edged" for some extra gains that are noticeable), all the quad valve heads have problems, and the list goes on. I egdged the head on my 2.4 PT Cruiser and the torque increase is definitely noticeable, equivalent to the amount of power she used to have empty and is now the same with 500lbs in her (very identifiable on hills and at lower rpm power levels) and having to shift on those big hills. I also lost the "jump" at 3000rpm, you know, where the engine has to rev up to to have power, gone, she pulls all the way to redline without huffing hard above 5000rpm and she is all stock down to smog requirements of California. She is cleaner than the bottom average for smog limits, so can't go wrong there, either. 
 
Have you ever had anyone tell you a small block 283 sounded like a big block Mopar? I have. Including being able to pull the front end off the ground of my 39 Nash after it was done with this 283. I can set off car alarms outside when idling by alarmed cars. One of the reasons I stopped driving the Nash to work actually.
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Rich

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« Reply #24 on: January 23, 2011, 05:55:46 PM »


My whole point about using the 452's over the 915's is who is going to go to all the trouble of porting the 915's and then put in a cam with more than .480" lift in a tiny little 361? That would be a complete waste of time and money. If you're going to go to all that trouble you better have some cubes to go with it!!
I think he's better off with a mild cam, HP manifolds and a good 2.5" exhaust system using the stock 452 heads.
krautmaster2011-01-23 22:57:03
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« Reply #25 on: January 23, 2011, 06:32:25 PM »

I don't like running greater than .480ish on the street with a hydraulic cam either, a little hard on the lifters and drivability on the street, roller cams are different because you can have a shorter duration.  Me, I would run the 915 heads on the 361 all day long over any open chamber heads, what with the short stroke and lower compression with the 452 heads.
 
I have a 361 myself, guess I will just have to build her up myself and see what I can do with a 4.125 inch piston, might go with 440 rods and crank, come up with a 401 stroker right from the start. There are SB Ford and Chevy (and Olds) pistons that can work with a little bit of finesse.
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Jason Goldsack

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« Reply #26 on: January 24, 2011, 03:13:06 AM »

Right now it has a 383 Magnum cam in it and seems to work not to bad.. but with the weight I'm thinking an RV grind might have been a better choice

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Jason

(Eileen)1965 Chrysler Windsor, 361/727/2.76 16.49 @ 86 mph

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« Reply #27 on: January 24, 2011, 06:08:55 AM »

There isn't that much difference between the two, both are a slight increase in stock duration and slight bump in lift, so changing the cam isn't worth the cost and time.
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Jason Goldsack

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« Reply #28 on: January 24, 2011, 08:00:07 AM »

Maybe switch to a different rocker ratio?

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Jason

(Eileen)1965 Chrysler Windsor, 361/727/2.76 16.49 @ 86 mph

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« Reply #29 on: January 24, 2011, 08:06:09 AM »

Not worth the cost to increase the lift by another .030 (figuring the lift is around .450ish). That's sever hundred dollars to do it, what you need in stockish form is compression lost from the 452 heads. You went from a 68cc chamber to a 87cc chamber, which dropped your compression by a whole point. Not the direction one wants to go to make power (and torque).
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