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Few questions... (Read 3380 times)
Scotty
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Few questions...
02/26/10 at 12:06:32
 
Hey guys, sorry to keep posting these noob questions...  I just haven't been able to fine these answers anywhere else...
 
1)  Is there a way to determine how much CC's a head will have when it's milled?  Any mathematical formula?  
 
 
2)  How much HP do you guys think a 360 with just 090 heads (milled .015), Eldebrock Performer intake, Eldebrock 650 CFM carb, The Summit 'Big Cam' (Lift .496/.521, 224 int./234 exh. at .050 lift) and a basic cam accessory kit?
 
Thank you
 
-Kyle
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Re: Few questions...
Reply #1 - 02/26/10 at 14:15:06
 
goin from memory, I believe the cc is 1.6 cc per 0.010 milled, so an 0.015 cut would be about 2.4 cc.  If you have a copy of Performance American Style its in there.
I have a similar 360, but with headers, 750 Holley, and a torker intake and based on its 12.0 at 115 mph performance I estimate it to be making about 400 horsepower.  The heads are not ported, but they were prepped by a local race shop which has been shown to help by 30-40 HP on other engines.  So I would estimate that you would be 350-400 HP depending on the exhaust you run, and the valve job on the heads.
ralfy
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Re: Few questions...
Reply #2 - 02/26/10 at 16:45:00
 
I was told that 0.010" cut would be about 1cc, don't know how accurate that figure is.
 
Maybe look at pistons while you are in there to bump up compression a bit. I beleive slipping in a set of 343 4V flat tops is a good old school trick to get the compression up a bit.
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« Last Edit: 02/27/10 at 05:04:27 by WestOzJavelinMan »  

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Re: Few questions...
Reply #3 - 02/26/10 at 19:44:29
 
machining off 0.001 will reduce the volume by 0.16cc
 
Norm
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Re: Few questions...
Reply #4 - 02/27/10 at 02:41:39
 
Ok, I'll go with you guys, 1.6 it is. If you clean up the chambers and unshroud the valves how much does that give back? I guess the best option would be to cc it when finished.
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Steve Avery
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Re: Few questions...
Reply #5 - 02/27/10 at 03:11:32
 
Depends, so you give or take would be right back at stock volume. You could look at valaves with flat bottoms instead of the stockish relieved ones but the cc reduction is probably infinitesimal. With .090's the shrouding with stock valves is minimal anyway. Since stock volume on 58cc heads is roughly 57 to 59 you'd need to mill more off or go with specific pistons to get whatever your goal is.
 Steve
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Re: Few questions...
Reply #6 - 02/27/10 at 03:33:40
 
Quote from Aussie69Jav on 02/26/10 at 16:45:00:
I was told that 0.010" cut would be about 1cc, don't know how accurate that figure is.

Maybe look at pistons while you are in there to bump up compression a bit. I beleive slipping in a set of 344 4V flat tops is a good old school trick to get the compression up a bit.

 
 
I was planning on using the Wiseco Forged Flat-Tops in the future, but that isn't for a while yet (either that or planning on getting a set costum made, thats if I can find out enough about pistons by that time, though.)
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Steve Avery
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Re: Few questions...
Reply #7 - 02/27/10 at 05:47:50
 
A set of vintage 343 pistons would work too. What are your goals as far as characteristics you are looking for? Acceleration? Top Speed? Responsiveness with broad torque? What kinda car? Jav, AMX, Hornet? Manual trans? Are you seeking handling as in being able to switch from right to left, maybe drift a little with predictable results? Straight line?
 Steve
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Scotty
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Re: Few questions...
Reply #8 - 02/27/10 at 08:47:43
 
I'm planning on using this set up in Imacarfan2's Spirit.  Basically what I want is a good stop light racer, so acceleration is preferred.  I may also race it in a few auto-crosses, but nothing competitively.  I was also thinking about using a sniper shot nitrous system (come with both 100 and 150 shot jets) but I haven't decided yet
 
Basically this will be my first ever project car, so I'll just be happy with something that can keep up with with a few of my friends cars (MR2, 350z)  My main objective is to learn...
 
So a 12 or 13 second car is enough for me, but faster is better  Grin
 
So, something to flog in the corners with decent straight-line performance would be preferred...
 
Also, I'm planning on either mating this up to a T10 or T5.
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Re: Few questions...
Reply #9 - 02/27/10 at 13:56:31
 
I had a set of 51cc heads re-done, they were cut to clean them up, and then the valve job was done with larger valves on a machine that also unshrouds the valve and the chambers ended up at 53 cc.  
If you are a noob I will repeat what has been said in other threads, but this is the thought process I recommend
1.  Decide what you are going to do.  Most important decision is how much you are going to drive on the street and what fuel are you going to run.  Assuming you want to be able to run on pump gas, you want to keep the dynamic compression as defined here: http://www.kb-silvolite.com/calc.php?action=comp2  between 8.3 and 8.7 to one.  8.3 is a safe number, 8.7 is marginal, may require octane boost, may require the timing to be pulled back but will work for occasional street use and trips.
2.  Make a realistic assessment of the rpm capability of the engine.  My advice is never ever plan on running cast pistons and rods over 6000 rpm.  This drives the cam selection, more duration means higher rpm to get in the power band.  Pick the cam for rpm, then use the silvolite calculator to guide your compression ratio.  As a general rule, a cam with 220-224 intake duration at 0.050 is a good cast piston choice, power band to 5500 or so.  If you go up a bit in cam, 230-237 intake duration at 0.050 power band will easily go to 6000 rpm and pushes the limit on cast rods or cast or hypereutectic pistons.  Not a grenade motor, but pushing to the limit.  About the most cam I would recommend for a car that really will be driven regularly on the street is an intake duration of 245-255 at 0.050.  That should get you to a power band that peaks at 6500-7000.  Probably the most extreme street vehicle on this forum is Steve Keown's street driven 10 second AMX.  His intake duration is about 261 at 0.050  At this point I had power brake issues, Steve is I believe still using power brakes.  The cam that Ken Parkman used for his engine builder challenge engine was I believe 254 duration at 0.050, a good choice for a competition where overall torque is important not just peak horsepower.
3.  Once you have the cam and compression that meet your powerband objectives, you will need to build the rest of the engine to take that power level.  With cast pistons and 5500 rpm, a pretty much stock rebuild will be fine.  Above 6000 rpm you will need balanced forged internals and good valvetrain.  If you want to push to 7000 rpm, the heads will need to be upgraded to support that power level.  
There are basic things that should be done to any AMC V8, improved oilpan, improved valvetrain, and so on.  Good luck.
ralfy
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Re: Few questions...
Reply #10 - 02/27/10 at 14:27:47
 
12 or 13 seconds, which ever you want can be done very nicely with low compression- 87 octane motor. The cam needs to stay around as Ralph said the 222-224 area, that will give great off idle and good to 5500. If you go to a 230 duration at 50 it will be fine too, just bring the power band up a bit-higher revs, but still under 6000.  The lift if kept under 500 well even 510, will allow more of the use of the stock parts, and great reliability. Meaning you can torture it with no fear.  Now as for the 090's be sure you have no original ex valve rotators.  They will drop valves sooner or later, but for some reason it has always been sooner Grin  These are the funny looking retainers and locks if they are still on there yet.  So when you get the valve job, just do away with them. If you would still want to do the head flow work, it will help, but not with the performer. You will need to step into the Torker or a Performer Rpm. Actually those both are better intakes for the bigger cams, and have plenty of bottom end power.     The heads as cast will work just fine for what you are trying to get for power.           Now to get the turning you are looking for, a steering box and both sway bars from a 79-80 AMX, or a 79-83 Spirit GT 6 or 8 cyl car.       You can get the same sway bars from a concord-meaning IF it has the rear one in it. Howevr if the concord has only a front one, then it is little, like the standard Spirit one.    This will make a nice handler, and driver all around.  Hope this helps. SH
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Low comp bridge pivot motors go fast too! Lots of 1978-80 AMX's, Nurse Bobbis' race car "Wild Thing", Mr. Happyfaces' "Trouble Maker" & many other AMC's. NAMDRA #2398 AMO#8370 Northstar AMC #09
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Steve Avery
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Re: Few questions...
Reply #11 - 02/27/10 at 18:51:48
 
Building on the advice above, and I'd stick with the more conservative .050 specs, particularly with stock cast pistons that are stock weight. It's not so much the rpm's determine cast vs. forged as it is reciprocating weight ( including rods and piston pins)  for cast vs forged. I'd say that 5500 is a conservative limit for the 360 piston/rod combo vs. a 390 or 401 cast piston/rod combo. But 5500 is a reasonable limit and if you pick the right cam after you pick the pistons, determine deck height and head gasket thickness, plus any head work- like bowl porting or extra cuts to the valve and seat- you can get the meaty part of the powerband below that or you can install and ignition box with rpm limiter to keep max r's inline with piston reliability if the engine wants to pull beyond 5500 or so (  my thought is with a quality set of brand new casts- 5800 would likely do no harm- but haven't tested that personally ).
  Crucial, if autocross is in the future, is looking at this gentleman's experience and seeking his advice:http://www.theamcforum.com/forum/the-story-of-my-engine-by-ray-larson_topic12796 .html . I'd recommend peripheral to that based on a respected vendor's advice- getting a 7 quart pan ( and a crank scraper ) as a minimal start for lower end mods when consistently throwing a car through a series of turns. Bulltear might have both or he has scrapers and possibly redos of the 6 quart police pans. If you ran an extra quart with a police pan and a scraper you'd likely be ok. Ask Kelvinator on here about that.
  Another place to look for at least a fatter front sway bar is an Eagle ( like the sports oriented SX-4 ). The rear attaches much different through a pair of rubber lined clamps. If you got the rear set-up complete too- there's no reason I see that you couldn't use the Eagle rear bar. I'd have to look to jog my memory as to if you'd have to drill the rear frame rails. I seem to recall the clamps attach to what looks like an idler arm bracket and pin that bolts to the frame. Another choice at a reasonable price is a used set of ADDCO bars.  
  Hope these thoughts help.
 
Steve
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Re: Few questions...
Reply #12 - 02/27/10 at 23:39:39
 
The SX-4 bars are smaller in dia.  But still not a terrible option.  If you check out Ray Larson's write-up.  It is just plain awesome. Good idea on that Steve.    The advice I gave you on the 360.   Is from my own and other friends experience. I can tell you I have been over revving stock 360 engines with bigger cams for years. My SC/360 has been ever 7000 a few times Grin Grin Slipping clutch between gears.  I have used many dif years of them in original condition with 10 pounds pressure at an idle, just pull the cam and swap in a new cam lifters chain and gears, and valve springs.   I have used and am currently using bridge pivot headed and early single rocker motors. I am not afraid to shift them anytime a 6500, and still drive them all over.      But I won't give that advice to anyone simply because, you are making it new, and it is costing you money, would hate to see you have it fail after the expense you are going through. I use an extra quart in all my stock pans. It works just fine no problems, I do not road race, just Drag Race and drive them around, and torture them for parades. Everyone loves a good smoke show in a parade.      So that is why I say to use the lower lift, and the duration around 222 and not to go over 230 for what you are doing, just want you to have good luck as well as be able to use it along time and be very happy with your outcome.          So I hope I did not step on anyones toes, if so I apologize ahead of time. SH
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Low comp bridge pivot motors go fast too! Lots of 1978-80 AMX's, Nurse Bobbis' race car "Wild Thing", Mr. Happyfaces' "Trouble Maker" & many other AMC's. NAMDRA #2398 AMO#8370 Northstar AMC #09
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Scotty
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Re: Few questions...
Reply #13 - 02/28/10 at 02:08:29
 
Honestly, until I get a line on some better income, I probably won't be building the bottom end - so I have time to decide if I want to go all out or not (plus I can always upgrade cams later, the big Summit one is only 59.99)
 
Will the cast pistons work well with say, a 100 shot of nitrous, or should I abondon the idea and just save for when i actually do rebuild the bottom end?
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Re: Few questions...
Reply #14 - 02/28/10 at 03:35:17
 
Quote from Scotty on 02/28/10 at 02:08:29:
Honestly, until I get a line on some better income, I probably won't be building the bottom end - so I have time to decide if I want to go all out or not (plus I can always upgrade cams later, the big Summit one is only 59.99)

Will the cast pistons work well with say, a 100 shot of nitrous, or should I abondon the idea and just save for when i actually do rebuild the bottom end?

 
 
LOL Instigator, you runnin' for office? You didn't step on anybody's toes with that well stated piece. Wink Scotty, I didn't mean build the bottom end, I just mean controlling the oil. If you are gonna twisty turn and keep the revs up you gotta control the oil. It has to get back down to the pan where the pick-up can get afresh charge to plug all the little internal oil leaks that a stock AMC V8 is inside so all the bearings get oil. The stock pump generally pumps up more oil to the top end than can efficiently drain back to the pan- hence the extra capacity in a pan that also allows the oil to get around to the pick-up. Come to think of it the police pan really is nothing special except for baffle. You could modify a stock pan to more or less do the same thing. Now, I haven't done this, but anb old timer showed the vendor I spoke of earlier a long time ago and the vendor, who also races or used to race did the mod himself- so he knows it works. The stock pan has a series of slots around the circumference of the baffle. They don't work. If you drilled a series of holes inside the folded lip of the baffle they are more in line with the oil slung off the throws and will be more effective in channeling enough oil around the pick-up to keep the pump supplied to deliver some oil to the bearing. That extra quart, preferably two, will always keep some oil in the bottom before the pump delivers it all to the heads. The series of holes inside the baffle lip will ensure the oil doesn't sit on top the baffle rather than pooling around the pick-up where it should be.
   Read that article for other pan mods directly aimed at keeping the oil around the pickup when turning. But that's up the road. You can do things in steps and than step up your performance driving as you incorporate more modifications.
 
Steve
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