An interesting 360

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Les Szabo

An interesting 360

Post by Les Szabo »

Thought this was interesting.......

Take 1 stock 1974 360 block, 8.2:1CR - Install a pair of 675 318, yes 318 heads on it with the 1.88/1.60 valves, apply some throat work so the head flows 185cfm @.400". Install a Holley 600cfm Carb, and Eddy Performer 318-360 dual plane intake, A Comp cams 260H hyd. Stock 340 valve springs, Summit cheapo headers, and voila>with no tuning

RPM.............TQ/HP

2500...........355/169
2600...........349/173
2700...........349/179
2800...........351/187
2900...........363/201
3000...........366/209
3100...........367/217
3200...........362/220
3300...........361/227
3400...........361/233
3500...........363/242
3600...........362/247
3700...........359/253
3800...........362/262
3900...........361/268
4000...........360/274
4100...........353/276
4200...........346/277
4300...........343/281
4400...........339/284
4500...........332/285
4600...........334/293
4700...........327/293
4800...........325/297hp
4900...........316/295
5000...........304/290
5100...........296/288
5200...........290/287

Nearly 300hp from a Slug!

Les
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Post by Pete »

A Slug is still a Slug ;)

Good find.......... :read2:
Pete Wiseman; Cambridge.

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Post by Mossy68 »

What years would have used the 675 heads ?
It's all about Smiles per gallon !!!
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Post by MilesnMiles »

Those torque figures are impressive. Everyone gets caught up in hp numbers; torque is where it's at and 360+ for a 318 is very impressive.
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Post by Mossy68 »

MilesnMiles wrote:Those torque figures are impressive. Everyone gets caught up in hp numbers; torque is where it's at and 360+ for a 318 is very impressive.
I agree Miles. Been some interesting stuff on here lately regarding small blocks.
I like your choice of heads , and looking forward to the results. :thumbright:
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Les Szabo

Post by Les Szabo »

MilesnMiles wrote:Those torque figures are impressive. Everyone gets caught up in hp numbers; torque is where it's at and 360+ for a 318 is very impressive.
Its a 360ci Miles with 318 heads with the bigger valves fitted and some porting.......675 heads are nothing special Gary, think they are from '71>'75?

Les
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Post by MilesnMiles »

The following spec engine with small valve J type heads and low compression ran in the 12's with 3.55 gears.


Talking of low budget, fast 360s, check the basic spec and how fast this combo ran in a chunky Challenger

We found this inexpensive every day package right out of the Summit Catalog. Summit's low-buck engine kit, cam timing set, and parts are all high quality. Acme Engine Company's machine work was top rate, contributing to great engine seal. Proper porting to the 1.88/1.60 smog heads combined with all the above gave us a freaky-fast SBSB combination. According to our Barry Grant Professor II computer, our SBSB is making 351 horsepower.
This car ran 12.7!!!!!!

SBSB CHALLENGER CHALLENGE
Specs
Engine: 1978 360 with .030 hypereutectic 9.1 pistons
Heads: 1978 casting "596" 1.88 intake, 1.60 exhaust ported
Cam: Summit Hydraulic 441 lift 218/228 duration @ .050
Induction: Edelbrock Performer RPM Air Gap with 750 Holley Double Pumper #74 primary, # 80 secondary jets 14x4-inch K&N with XStream top
Ignition: DUI with full advance in by 3,000 rpm 12° initial, 38° total
Exhaust: 1 5/8 Hedman headers with 2 1/4 full exhaust generic 2 1/4 turbo mufflers
Transmission: 904 by Pro-Formance transmissions, 3000 stall no-name 10-inch converter
Wheels/Tires: Weld Draglites, 15x6 front, 15x8 rear, 235/60 BFG Comp T/A Drag radials (rear) 205/70 off-brand tires (front)
Suspension: Stock, gas shocks (front) air shocks 20 psi (rear) pinion snubber resting on floor

The full article is lengthy and start a third down the page titled;

Slick Budget Small-Block, Part IV
This is more than just a test


http://dynamicconverters.com/news.htm

The article proves the value of a really well built transmission
Les Szabo

Post by Les Szabo »

Yes Miles a stock 360 can easily be made to make hp with good flowing heads, and good machine work, however in that case it needed pistons/rings, a re-bore etc. etc. to bring the compression up to 9.1, thats £££'s. A stock 8.2:1 360 bottom end with 318 heads would get you close to 9:1 with a steel shim gasket. Its just another way to skin a cat without taking the block out of the car, assuming its still runs ok.

Yes the 318 heads had some work to bring them into line with the bigger port 360 heads cfm flow but there are plenty of 318 heads about that you can get as a gift. A smaller intake port that flows similar to the large port 360, matching manifold with a smaller carb would make it a better street engine with better throttle response, mileage etc. and still have respectable hp/torque no's.

Using a stock bottom end and 360 heads can also be made to work but you'd need to mill the 360 heads .050 thou at least for CR which mucks up the stock valvetrain needing custom pushrods to keep lifter pre-load correct, and the end intake gaskets would be too thick cos of the big mill on the heads which could cause issues.

These are not performance builds I've put up but show what you can do with stock parts, good stock heads with matching cams/intakes and good machine work for your average low buck street build and just shows what can work for the average street guy on a budget.

There are plenty of performance BB/SB stroker builds also which are interesting enough, but not everyone wants a Big hp motor. It goes without saying that your nicely built stock motor that makes some power will not perform if your trans is Bananarama!.

Les
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Post by MilesnMiles »

Les, I agree. What impressed me is that the 360 build I posted is cheap if you are rebuilding a stock block; no lairy cam, no expensive rocker gear and home ported heads. I thought it was impressive.
Les Szabo

Post by Les Szabo »

I guess to us it is impressive, 350hp from a 9.1 360 with no cam in it, to them its almost the norm, in some states all you have is 87 octane, they've become experts in building low CR motors that perform, they've had to. And thats the type of builds I've been putting up to show exactly what you can do with low CR but good matching parts.

What we tend to do over here is over cam most engines, and don't have enough CR for them most of the time and have heads that don't flow enough which is a recipe for a slug. Admittedly we don't have a good machine shop with people that can port heads almost at the end of our road like they have, but there's power in them there slugs!, there's some very interesting articles about head porting DIY that show amazing results, especially on 318 heads.

I was well guilty of over camming my 440 race car for the CR I had, but it still ran ok, better when I got a decent pair of heads on it, but it could've been a lot better. I've learnt some since then and would do things a lot differently now.

Les
Les Szabo

Post by Les Szabo »

Perhaps some of you will be interested in reading this, its rather long :happy1: :read2: ...about 273/318/360's, head technology etc.

http://www.allpar.com/mopar/4bbl.html


Les
Les Szabo

Post by Les Szabo »

Update to above 360ci with ported 318 heads.....

The head flows.

These 675 318 heads.....................stock 596 360 heads

Lift..........IN/EX.............................IN/EX

.100........74/59.............................57/49
.200.......128/119..........................112/88
.300.......173/150..........................168/109
.400.......184/170..........................194/136
.500.......189/182..........................192/142
.600.......191/189..........................196/144



260H cam .440/.440"......................stock 318 cam,.374/.399 lift

RPM.........TQ/HP.............................TQ/HP

2500.......362/172..........................353/168
2700.......354/182..........................351/180
2900.......362/200..........................358/198
3100.......369/218..........................355/209
3300.......369/232..........................357/225
3500.......366/244..........................354/236
3700.......366/258..........................345/243
3900.......366/272..........................343/255
4100.......364/284..........................331/258
4300.......351/287..........................312/256
4500.......341/292..........................303/259
4700.......341/305..........................294/263
4900.......326/304..........................277/258
5100.......304/295..........................260/252
5200.......299/296..........................254/252

ok, thats probably quite enough about SB's......

Les
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Post by Cannonball »

put that mtr in regular cars that run what you brung over here and yer nuts will ache for a week from laughter,
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Post by MilesnMiles »

Looking at those flow numbers I'd still buy my heads again!
Les Szabo

Post by Les Szabo »

No Miles your not with it, your heads on that motor wouldn't work. The idea of that is to have a reasonably good flowing head but with small fast ports to compliment the small short duration low lift .440" cam to produce good torque and hp for that low CR motor at low revs, under 5000.

Your heads are desgined for a Higher CR 9.5>10.1+ motor that will use a cam of around .500>.550", and duration in at around the 230+deg mark@.50. and make its full power in the 5500>6500 rpm range.

Big Blocks are a different fish!


Les
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