MORE TORQUE

FSD, that is a beautiful reply lol. I think you nailed it, I was thinking an accumilation of everything when it really comes down to valve timing. everythign else can improve it but the valve timing still dictates torque in the end.

this is much more of a cam topic as it seems it's the heart of what I'm looking for/try'n to understand

area's to think about:
Overlap - more over lap less bottom end, less overlap more bottom end
Lobe Centers - tighter gives more overlap, wider gives less overlap
duration - more is more overlap, less is less overlap
Lift- increases power without moving the power on the power band
these came from various websites, all conferming eachother.

so I'm guestimating for torque we can bleed little off to gain more. from what I have seen I improved toque alot from going stock to not...
so from the following I get

256/256 .233 114 has 28* overlap, with 1.5 rockers .350 lift, makes 68hp 117tq (140tq @ <1100rpm) (stock engine)
260/260 .300 112 has 36* overlap, with 1.6 rockers .480 lift
264/264 .300 112 has 40* overlap, with 1.6 rockers .480 lift
264/274 .300 110 has 49* overlap, with 1.5 rockers .450 lift, makes 135hp 167tq (95hp 168tq with same stock engine carb)

just guestimating the middle 2 could make more or less torque? I would guess more, but at the cost of HP.

I guess that's why the CAM is reffered to the heart of the engine.
 
Heart, Personality , The most duration with the least overlap using the highest ratio rocker would be the trick , but keep in mind it will be rpm limited so there is always a trade off , a higher compression ratio than would be normally used can gain back a loss from overlap , its a combo that makes it , all parts in Harmony
 
You have to see where your heading, using past precedents, then forwarding actions, then review that its done. Richard, your really looking at a T-code 200 Sprint engine with a special 2v carb, headers, cam/head/valve mods to get past the poor exhast flow.

Lets recap on a 352 hp net at 6700 rpm /316 lb-ft at 5000rpm C-code based 2-bbl 289 with K-code solid lifter cam, and show what a soft head/NASCAR restrictor plate tune would be like to draw out power and torque which tecnically wouldn't be there considering the carburation to cube ratio and air flow readings. Once that's pulled apart and understood, apply the concept to a 200 or 250.

Stock 2-bbl 289 power was rated back in the day as 195 hp gross, but was probably 156 hp at 4400 rpm, stock torque was most likely 225 lb-ft at 2800 rpm. Compression was about 9.2:1, which is elevated to 9.25:1 for his engine. It uses stock 2-bbl 2300 series #4412 Holley 500 cfm with 1.375" venturis, and stock 73 jets and two stock 62.5 thou power valve channel restrictions for this new found power. That means that the carb is being sucked within an inch of its life at 6700 rpm for its 293 cubes and at 85% VE, the carb 'sees' 482 cfm. Stock was the 2-bbl 2100 Autolite 1.14 = 300cfm, 1964 - '67, on 289's

Vizard and others use traditional power predictions that take peak head flow at 10, 25, or 28 inches on a standard piston size of 500 cc for 4 cyl, 625 cc for a 5 liter /305 cid engine, multiply by a factor, and thats your maximum power. A scala factor is applied to correct for engine sizes above or below. A 293 cub engine making 237.5 cfm at 28 inches can make 450 hp at 8500rpm if there is no choke point. For an all encompassing link, see http://www.wallaceracing.com/calcafhp.php

Now, the last kicker was the heads were based on a 237.5 intake, 185.6 exhast, and "because of the two-barrel carburetor, exhaust-port flow was intentionally limited to less than 80 percent of intake flow above 0.400 lift to maintain a scavenging effect. Read more: http://www.hotrod.com/techarticles/engi ... kYG0GTeI80%" Itallics mine, and its all based on 1.94 intake /1.60 exhast.

The intake manifold, a single plane Edelbrock Victor Jr. intake with an adapter that’'s hogged to match the carb’s bore size, is one of the best, so its not really feasible to copy it on a small six. It's like comparing a two hole 1.675" discharge to a nice square verses one 1.75" hole to a rectangle.

So running the numbers, we have a 289 V8 making really good power very high up in the rev range, and, at just over an lb-ft per cube, quite poor torque at 316 lb-ft. Scaled down to a 200 with 1.75" intakes and 1.45" exhasts, that's 244 hp and 219 lb-ft. Due to poor head flow and limited carburation, torque and hp occur at too high an rpm.

Back tracking to an EFI 3.3 non crossflow Holden engine in 1985, it had 195 lb-ft at 3000 rpm, and 142 hp at 4800 rpm, with a 264 degree cam with 8.8:1 compression. 1.625" intakes, 1.4" exhasts, 12 port head with similar head flow to a D7 head. Still less than 1 lb-ft per cube. A 250 EFI Falcon with 8.8:1 compression, 264 cam, 247 lb-ft, or less than one lb-ft per cube at 3000 rpm.

Somewhere between the two is where best low end torque curve lies.

I'd personally like to see 9.7:1 compression, maximum torque at 3500 to 4000 rpm( 207 lb-ft at 4000rpm being possible), power of 193 hp at 5750 rpm, and a 2-bbl 2300 series 350 cfm #7448 carbwith 1.1875" venturis, and a 280 degree cam which produces those figures with a head that meets 80% of the peak intake flow at 360 thou. Based on Wallaces website, which calculated 450 hp at 237.5 cfm, I'd punt for 249 hp flowing heads to get 193 hp. You'd only need 175 cfm at the intake. To get power at 5750 rpm, your internal port size outside the intake valve needs to be only 1.338", and a D7 head is about that already, but the intake runners are too small leading up to that to allow the 1.338 port size to be effective. Thats why people favour the large runner intake manifold, as the ports then have a chance to get good air flow from the carb.

With that combo, you'd still get power, but get excellent lower speed torque.
 
You guy's are way out of my league. I crunched numbers with some of the members here and other sites, for a couple months designing my engine. After comparing a lot of different cams, in a couple different dyno programs, I finally went with the Isky 321256. 256/256, 112 lobe center and .450 valve lift, 1.5 rockers. On paper and seat of the pants, it works. Can't backup any data with a dyno run. Torque curve is extremely flat from 1200-4500rpm. My engine was built entirely around the torque curve since it's in a 4x4 with horsepower not being a concern. Granted, I'm running the aluminum head, but cam choice made a huge difference. This is just FYI info, not meant to make any suggestions.
 
Explorer":2jzo1t5b said:
You guy's are way out of my league.

Nah, man,its just that we've gotten our hands dirty, and are now checking on what works. If you use my favoured Pontiac website http://www.wallaceracing.com/chokepoint.php, and get a copy of PipeMax from http://www.maxracesoftware.com/pipemax36xp2.htm, it forces you to analyse the same stuff, over and over again. What you loose in top end power with a low duration cam you can generate with a brilliant exhast, lesson learned from Ford and Holden Australia. I had nine long years without a registered Ford Six road car, and did a lot of research work on air flow. Jack Collins here was undespensbile for info.

When I got a Mustang and Explorer, I fitted up Alex Peppers EEC5 real time data logger for 120 dollars US, and nek minute, I could understand where modern engines got there power from.

Nine times out often, Pipe Max valiadates what many of us here already now regarding peak power. What is missing is how that even a short stroke in-line six makes excellent low end torque. If you've got personal experience with in line engines, or combinations with similar results, you can then figure out why certian engine combos work. I read lots. Every single Pop Hot rod and Hot Rod and Australian Wheels and Australian Street Machine mag from 1980 to 1993 give me a great index on the worlds cars, so you can benchmark of compare a combination. Any article on a car engineer should be read dilligently, 'cause those guys are awesome. Actually, a 1985 Wheels article had US GM engineers testing TPI Corvettes and Camaros in Aussie, when durability testing Aussie Borg Warner 7.875"diffs and PBR brakes. GM Holden Australia was technically bankrupt, and the Yanks came to purchase really good brakes and diffs for the F-cars and Corvette, and all those guys wanted to do was just drive EFI six cylinder Commodores and Falcons. Why? Because in line sixes were already being consigned to the wreckers yard for GM. The US committe car is in essance a lot of really talented people talking the a$$ off really mundane details, just like us. Go figure!

A lesson from the Mini Cooper S and Cleveland headed Trans Am and tin top Aussie racing days of the 60's, 70's and early 80's. If you have a free breathing head, you can under cam your car with a hi intensity cam that has great 50 thou and lift figures compared to the other cam profiless, and the results on short and long stroke engines are quite stunning. Off idle torque is then better than before, and it'll hack huge gearing without effort.

If your head is poorer breathing, you have to cam it up, and work around the cfm restrictions with better gearing, and compression. My 1982 3.3 Mustang when it was 1-bbl pulls almost the same gearing as the auto Falcon I'll describe, with a 256 cam too

1995 to 2003, I ran a very similar profile to that on my 1984 alloy head 250 Ford Falcon. See http://kastang.tripod.com/fsp/xecute.html

US Heatseaker HS10E 252 Cam, a 252 econo cam with very intense lobe lift for 50thou figures over 205 degrees and total lift about 450 with 1.73 ratio lifters. It had 1.75" intake valves, headers,1.875" exhast, 1.3" ports, 500 Holley, 3-stage auto with stock 1650 rpm stall converter, 2.77:1 open wheel gears, power steering, 245/60 14's for 2232 rpm at 60 mph in 1:1 top, 2.39:1 first gear, 3064 pounds.

What was significant is that in the first 50 feet of any off the mark traffic light race, no matter if it was a turbo Subaru WRX, Mitsubishi Evo, or 351 Ford, it would be first cab off the rank. It was quiet and no descript,and cops would look at the other cars racing you. Best thing was how it would quietly leave rotaries like RX-7's, for dead.

Having so little duration means that off idle torque is just massive. I use a modern EFI vehicle as a baseline for my car tuning business at XEC. My 4 liter/245 205 hp SOHC EFI with 5 speed 235/6016's and 3.73 slipery diff and 2837 rpm in 1:1 resulted in a 2.48:1 first gear which was has 31% lower gearing and, at 4034 pounds, 31% more weight to move. It is significantly more Mondayish off line than my old 4.1/250. My wife always comments on this factor, that in off the mark hook up, fat tires with a 250 in line six seams to be an unmatchable combo.
 
X? Were you suggesting him use a 280* cam? just clarifying for my own curiosity.

What if Richard were to separate the intake as in a Dual plane setup? As in just braising in a port divider under the barrels. It would increase his bottom end torque dramatically as well as lower the RPM that he see's peak power. It would also smooth out his idle a bit which has been a bother of his since he got the 264/274 cam put in the engine. Might smooth it out enough to go to a 274/274 cam even? I am pretty sure that producing lower end torque like that would be less likely to deteriorate his fuel mileage which is also always a major concern for him. The only downside to this is that he would have to tune in everything again to match the fuller intake into each cylinder, improving intake efficiency anyways.

Just throwing that thought out there.

Gerald.
 
"...240Z, Austin Healy 3000..."

"Square" engines, no? (stroke=bore)....
A stroker (250/4.1 is a 'stroked' 170/200) has more tq - and a stroke bigger than displacement for each cylinder.
 
170-3tree":3sntrone said:
X? Were you suggesting him use a 280* cam? just clarifying for my own curiosity.

Yes, if the head flow is poor, you can increase duration without camminess, especially on the US 200 which has the same rod length to stroke ratio as the US250...1.5:1. Generally, the old E303 280 degree Ford 5.0 cams and mechanical K code 289 cams were the level where emissions compliance and waranty claims started. When head breating and intake are improved, the cam needs to be less in lift or duration to avoid camminess. The level that latent/lazey bottom end performance with idle chop sets in for 3.3 to 3.7 OHV engines with poor breathing (Holden L6's, Valiant 225's, Ford 188/200/221's ) is about 280 degrees. Bigger engines can cope with a 30/70 duration cam with ease, but a Cross flow 200 has a lot more chop at idle compared to a 250 x-flow, but the log 200 non has a 1.5:1 rod ratio; Our Aussie 200 cross flow has a 2:1 rod ratio, and is suceptable to poor lowend performance (reversion) compared to the log 200. A practical note again... big engines aren't influenced as much as small engines by large cams, but a smaller engine will really chop if you compare it toa bigger one.

Back in 1988, my mate Blair was selecting a 295 degree cam, and the guy as US Speed and Spares had a 302 Cleveland 2V headed car with 4-bbl carb and with that cam, and it had a worse idle than a Boss 302 mustang, a notably lopey engine. When he fitted it to his 2v headed 4-bbl 351C, it had heaps less chop and was quite tame. The issue is that the Aussie 302c was a 2:1 rod ratio engine and short stroke was very suseptable to poor idle. Same with the Aussie 200 x-flow verses 250 x-flow.

The division of the log from "one hole feeds six" to "hole one feeds 1,2,3 and hole 2 feeds 4,5, 6 will eliminate reversion when a cam is bigger. Its close to dual runner, but not quite. You just use a stock 38 Weber or 2-bbl Rochester style adaptor with two 1.375 or 1.675" holes, and drop it down 2.165" to the nine flutes in the log floor, and drill a 1/4 transfer hole. Not a biggie.
 
As a cheap test run, a small plate could be made onto a two bore throttle spacer and made to fit in the hole you have provided for the carb. It could be made with a slight notch cut in to tighten up the clearances a bit. It wouldn't be a true dual plane situation, but it would give you some of the benifits without COMPLETELY commiting your worked over head into the mix. IE could be removed.
Also, it might be better than full sealed, allowing the vacuum signal between planes to be communicated, just the same as an x-pipe in the dual exhaust.
Just spouting theories.

I get what your saying X. It hard to think more cam in smaller engine though, when most of the time, you are taught that smaller engine gets more lope with more cam. I guess that is a basis without considering flow capabilities at all.

Gerald
 
:unsure: Just thinking out loud, but it's too bad something like a 221 crank or stroker kit wasn't available here to drop into the 200 block that would give a nice little increase in torque :nod:
 
I have heard of such plans being discussed as well ad some pretty awesome plans about blocks, don't know what came of the 221 idea, but I know the block plans got put aside because dev costs would be extreme.

Honestly, calling up scat and working out plans with them for such an arrangement wouldn't be too much more than the "kit" would be. Just a bit more for all the initial expenses and factoring that would have to take place. I would worry about cam position being the biggest issue here.
 
:unsure: That's true so far I have never even seen any pictures of a 221 apart and a 200 is plenty tight at the cam already :nod:
 
most fo us just use these for comutes

also how would one go about to make the begining of the torque band reach as low as 1100rpm but not any lower, reason I ask, some of my early dyno tests showed 140tq off idle (900rpm) to the tires, that was with a manual trans. 900rpm is not usable except for off the line. it seems my current torque isn't usable at lower than 1600rpm, have to rev it higher.

NASCAR style didn't use this engine, but their theory can work and that's what I want to understand.

Its got twice the torque as your 200 from off idle to about 2500 rpm.

but get excellent lower speed torque

built entirely around the torque curve since it's in a 4x4 with horsepower not being a concern
*********************
The most TQ @ the lowest engine rev (in a moderate [read low cost]) on the 250 (or as asked in the thread - 200) cuz rather NOT spin the tires.
what makes more torque? (some guestimates)
short duration cam probably in the 254 range??
high lift up to .495, more if possible
long piston stroke
closer lobe centers
CR??

I'd say:
*wedge combustion chambers,
*shortie headers,
*1V carb (W/big throat/boar),
*the '77 + head (I'd assume),
were a few things U left offa ur list I believe (don't have certainty).
I believe the 250's highest tq (mine's a '69) is @ 1500 rpm. I like that due to camber on off rd situations and traction needs. With 411 rear I'd rather not get up over 2500 too much - gets slippery.
 
bubba22349":1ddwp7l2 said:
:unsure: That's true so far I have never even seen any pictures of a 221 apart and a 200 is plenty tight at the cam already :nod:

221 cam is higher up in the block. it uses the same timing chain as the oz 250
 
You guys can get another 20 cubes with just a set of 50 thou over US Ipel pistons used in BMW's and Argentine TC racers, a set of custom 4.98" rods on the VW-Audi or Aussie GM Holden bearings, and an offset ground 3.35" stoke crank, same stroke as the little Falcon based HSC 2.3 engine. 10% extra capacity by stroking is always 10% extra torque, if the rod ratio is preserved. There is no extra weight...a 220stoker is ligher than a 200 Ford.

For you info, Fords colonial offposts and US were busy making a bunch of special six cylinder engines for 68. The two stunning medium block engines in 1968...the 188, the 221, and in the US, the first big block 250.

The Argentinian~Australian medium block, had a 8.425" deck engine, which was 622 thou taller; the engineers just added two links to the stock 144-170-187-200 engines timing chain to space the cam far away for potentially a 3.91" stroke. But the bigger engines started at just 188, and it became the 1968 Argentine and Aussie 188/221 block. First versions had 2.94 stroke with 5.37" rods (seven bearing 170 crank, for 188 cubes), then 3.46 (with 5.14" rods, for 221 cubes), and in 1971, it came out with a 9.38" block, 89 thou shallower, and 1 inch narrower than the US 250, but it still had space for 3.91" stroke with 5.88" rods.

Remember, it was October 1967 technically when the US 250 came out as a Ranchero pick-up option in the Fairlane/Torino based light utility vehicles.

The 188 rods and 221 cranks were used in stoker engine builds in Holden 186 engines...you could take a Holden from 186 to a stunning 235.2 cubic inches or 3853 cc's, a huge 27% increase, or 808 extra cc's for just swapping the crank and rods. The cam base circle diameter had tobe reduced, and the rods needed grinding back, the crank case needed a grind back, but 47 cubic inches is 47 cubic inches.

The US 200 can be easily taken out to 220 cubes within the confines of the 200 block. You offset grind the crank to 1.9" rod journals, and add BMW Ipel/Mahle or Ross/Denco equivalents. Deck is about 1.15", with 0.866" wrist pin, and a competition version of the Ford Pinto 2.0 4.96 to 4.977 style rod used. With a 56 thou overbore, you've almost gotten 221.

The operating envelope of the cam to crank clearance is stock, so no special cam or slipper skirts are required, but the stock small Ford piston profile must be used to clear the counterweights.

Rod ratio ends up at 1.486:1, whilethe stock 221 was 1.486:1 as well, so its the worlds easiest 221 conversion.

The rods are based on standard aftermarket Ford Kent/Pinto line references. The Ipel pistons are standard high end BMW replacements, made in Florida, and the best money can buy.
 
Speaking of BMWs, any thoughts on how the venerable I6 compares to the BMW "eta" 2.7l? Seems like in design and intention the two engines have a lot in common...
 
127 hp and 170 lb-ft from 164 cubes. Our Multi point EFI Falcon engines were doing that in 1988 (186 hp and 254 lb-ft from 239 cubes). The eta engine concept was a dead end 1983 concept for BMW. Though early dirty European spec 523i and 323i lost only a few foot pounds of torque to the eta engine, and BMW customers didn't like an engine that had a Ford Fairmont 200's rev range and torque readings.

The reduced rev range (4700 rpm I think on the first 325e and 525e) wasn't made up for by a twin cam head or dual resonance intake or by an elevated compression ratio with better mixture motion...it was a reduced revs, reduced internal friction via less cam bearings, increased capacity rendition of the 3-series six cylinder engine block, and even before its introduction, was based on an engine which was a hated orphan for BMW. Its home in the confined space of the 3 series forced BMW to adopt what were for their engineers hated siamesed cylinder bores.

The low rev engine base was due to it being the first production turbo diesel. Not the Rabbit, but the 1978 BMW 524td, and the M20/M21 engines were really a means of BMW farming out diesels to Ford for the Lincoln LSC, which used the engine during the dark years of the EPA's strict emission laws. As Germany and the EU standardised US 1975 emissions regulations in 1986, the engine lost more torque.
 
xctasy":wkqr2kux said:
The US 200 can be easily taken out to 220 cubes within the confines of the 200 block. You offset grind the crank to 1.9" rod journals, and add BMW Ipel/Mahle or Ross/Denco equivalents. Deck is about 1.15", with 0.866" wrist pin, and a competition version of the Ford Pinto 2.0 4.96 to 4.977 style rod used. With a 56 thou overbore, you've almost gotten 221.

The operating envelope of the cam to crank clearance is stock, so no special cam or slipper skirts are required, but the stock small Ford piston profile must be used to clear the counterweights.

Rod ratio ends up at 1.486:1, while the stock 221 was 1.486:1 as well, so its the worlds easiest 221 conversion.

The rods are based on standard aftermarket Ford Kent/Pinto line references. The Ipel pistons are standard high end BMW replacements, made in Florida, and the best money can buy.

Ooops. What a difference an A makes. Parts are Iapel...http://iapel-europe.com/prod/eprod_bmw.htm,

If any old block is sleeved, you can run standard M88/S38 B351983-1989M5 3.677" BMW pistons, but decks are 1.2598", but can be cut down.

BMW Euro Spec M5 1991.5-1996 S38 B38 335 hp engine had 95 mm pistons which are +60 thou for our 200 engines. Deck height is 1.2047", which can be shaved down. It runs a Holden/BMW/Datsun spec 22mm 0.866" wrist pin.

The crank can be ground back to 1.899 for the Holden bearing, or 1.890" for the VW-Audi bearing. Conrod to suit is the standard Kent 4.926" item, but with the Holden 1.899 or VW-Audi 1.890" rod journal and Holden/bmw/Datsun~Nissan 22 nn pin, not the stock 13/16" 0.8125" item. The common and hardy Holden 2250/2650 149/161/173/186/202 rod bearing (1963-1986), or the 1.4/1.5 Rabbit/Golf Diesel, G60 1781 cc, and early 2144 cc 5-cylinder Audi 5e/Fox/5000 engines were 48 mm journals. http://www.not2fast.com/vw/stuff/vw_engines.shtml
The B18c stroker, B20a5 Honda rod journal size is 48 mm too
There is a non custom same bore spacing Toyota T-series, Y series OHV or S-series OHC rod that does the job, but I can't remember which one it was.
 
xctasy":i3rpb9wg said:
The crank can be ground back to 1.899 for the Holden bearing, or 1.890" for the VW-Audi bearing. Conrod to suit is the standard Kent 4.926" item, but with the Holden 1.899 or VW-Audi 1.890" rod journal and Holden/bmw/Datsun~Nissan 22 nn pin, not the stock 13/16" 0.8125" item. The common and hardy Holden 2250/2650 149/161/173/186/202 rod bearing (1963-1986), or the 1.4/1.5 Rabbit/Golf Diesel, G60 1781 cc, and early 2144 cc 5-cylinder Audi 5e/Fox/5000 engines were 48 mm journals. http://www.not2fast.com/vw/stuff/vw_engines.shtml
The B18c stroker, B20a5 Honda rod journal size is 48 mm too
There is a non custom same bore spacing Toyota T-series, Y series OHV or S-series OHC rod that does the job, but I can't remember which one it was.

I need a bit of clarification. Some of the numbers I'm finding don't match up to yours.

The 1.6L Kent rod has a big end diameter range of 2.0825"-2.083".
The VW rod bearings have a bore range of 1.9291"-1.9298"; a difference of around 0.1534". That's a big difference to make up.

The VW rod bearings have a journal range of 1.8087-1.8094 (45.95mm) , not the 1.890" (48mm) you mention.

The stock size Holden bearings specs are closer (2.025") to fitting the Kent 1.6L rods; about 0.058" smaller based on ACL's website. Could the big end of the Kent rods be resized to fit the Holden bearings? Am I looking at the wrong VW bearings?

I'm not trying to be adversarial, I'm just trying to wrap my head around the numbers and make them work.
 
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