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470 low-deck build

Sweet5ltr

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Okay fella's, I've chosen that I'm going with the 3.915" stroke/6.535" rod (470ci) rather than 4.250" stroke/6.535 (512ci) for my build. A bit more compression height, dramatically less piston speed @ 6,000 + RPM, rod-ratio is much better. Compression ratio was chosen for the ability to run 87-octane for long trips, full-timing on pump, and no issues with PTVC. Car is primarily built for the street, it's not a dedicated racecar and is never trailered anywhere. Am I building a slug or what?

Combo:
850 DP
Mopar M1 Intake Manifold
Eddy 84cc heads
Lunati Solid 259/267* duration - .586/.606 - 110 LSA (78* overlap)
1 7/8" headers - 3" exhaust
9:1 CR (87-octane :popcorn:)
FTI 9" 5,000 converter
3.55 gears, 28.5" tire.
 
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Looks Great, IMO Less convertor for the Street it'll run cooler, plus i'd Go 10.5 and 950 Carb, other than that looks awesome to me !
 
The M1,the dual or single plane ? Did a 451 low deck,what a great engine.Converter a bit much for the street with 3.55's,I had a 3500 and 4.10's.
 
You are a pretty smart cookie 5ltr just seems like a bit too much cam and converter for a mellow street car. With a 3.55 gear and 5,000 rpm stall I'd bet you'll be on the converter alot
 
IMHO I think 10.5 with a open 84 cc head will ping. If you were to go with a 75-78cc chamber head with corresponding matched piston then maybe you could run 10.5. Although your big cam may bleed some of that off. Maybe IQ52 could help you out.
 
Looks Great, IMO Less convertor for the Street it'll run cooler, plus i'd Go 10.5 and 950 Carb, other than that looks awesome to me !

10.5:1 doesn't give me the ability to run 87-octane, remember, primary street use/power tour/cruisin' the coast. I would go with 10.75:1 if it was for a street/strip car.

The M1,the dual or single plane ? Did a 451 low deck,what a great engine.Converter a bit much for the street with 3.55's,I had a 3500 and 4.10's.

M1 Single Plane, have the hook on a dominator flanged M1, will run a Wilson Adapter or similar for my 4150. M1's are very, very difficult to find for a low-deck engine since they've been discontinued.

You are a pretty smart cookie 5ltr just seems like a bit too much cam and converter for a mellow street car. With a 3.55 gear and 5,000 rpm stall I'd bet you'll be on the converter alot

Converter is fairly tight, drives like a 10" 3,000-3,400 converter until flashed. I have a fairly large tranny cooler and electric fan setup. Problem with running any more gear, is it severely diminishes highway driving. Even with a 4,000 converter, if it's non-lockup, a 4.30 gear would be optimal. Issues present themselves as I would then be limited to around 128-135 MPH @ 6,500 RPM (accounting for no-slippage, perfect for strip). Building a road-trip car, also have to look at highway driving. 4.30 gears would require me to run 3,750-4,000 RPM on the interstate to keep up with traffic @ 75 MPH rather than 3,000-3,250 RPM with 3.55's.

IMHO I think 10.5 with a open 84 cc head will ping. If you were to go with a 75-78cc chamber head with corresponding matched piston then maybe you could run 10.5. Although your big cam may bleed some of that off. Maybe IQ52 could help you out.

No doubt it would, 10.5:1 w/ 36-38* timing, no way on a street car running pump fuel (IMHO). Not really believing I'm losing an incredible amount of power if I can run 34-36* timing on 87-octane vs. 30-32* on 10.5:1 with 93-octane. I have some friends that run 100+ octane, 50/50 with 93 octane to drive to and from the car shows due to 11.5-12:1 CR's; seems ridiculous to me unless going for every ounce of power for a strip-only car.
 
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i think i'd step back on the cam with 9:1 comp. a tighter converter would be a step in the right direction.
 
i think i'd step back on the cam with 9:1 comp. a tighter converter would be a step in the right direction.

Converter is tight, tighter than my previous 10" 3,200-3,400 converter. Camshaft should have a torque peak closer to 4500-5,000 RPM (I would imagine) in a 470, so I don't believe the converter is very far off from optimal, even speaking to FTI they stated it should work well. This differs widely from a 500-512 with a mild-camshaft that creates peak torque around 3,000-3,500 RPM; which would be PERFECT for a 3,200-3,600 converter. This is a relatively mild camshaft (overlap is less than MP .557...), no reason to not take advantage of head flow at higher RPM.
 
peoples concept of a pump gas street car are fairly subjective. i error on the conservative side compared to others. my thoughts are based on what i drive and what i expect from my driver, but that's only relative to me. i drive a 440 with 9.75:1 comp, eddie 84cc rpms, engle solid (238@.050", 110lsa-106cl), ch28, and tti exhaust. i use an old '66 street hemi converter, 3.23 gears and 28" tall tires. very pump gas friendly (93 octane), very easy reliable driver and will blow the tires off at will. in town or highway it gets the job done for me.
 
when i think of pump gas truly street engines; i think of in town and highway both. the more versatile the engine needs to be the more performance compromises there will be. i give up power for reliability and low maintenance; some folks won't give-up a nickles worth. it's just choices. there's a guy who lives around here that has a '66 chevelle with a really big big block. big compression, cam, and alcohol burning. he goes to the local cruises and to him it's a street car. probably doesn't stray too far from home. to me it's a race car with license plates. different strokes for different folks.
 
when i think of pump gas truly street engines; i think of in town and highway both. the more versatile the engine needs to be the more performance compromises there will be. i give up power for reliability and low maintenance; some folks won't give-up a nickles worth. it's just choices. there's a guy who lives around here that has a '66 chevelle with a really big big block. big compression, cam, and alcohol burning. he goes to the local cruises and to him it's a street car. probably doesn't stray too far from home. to me it's a race car with license plates. different strokes for different folks.

Great analogy, you're absolutely right, really it's an entire combination that must be versatile. I went with the 470 for all the reasons originally noted, but also that it's been proven an ultra-reliable stroker combination. Other than going like most, with a 'no replacement for displacement' approach (massive amounts of torque by 3,000 RPM, flatlined power by 5,500 RPM), it seemed logical to build a higher-power band for a street car with limited traction; going for a higher torque peak and greater HP potential. With the right converter, it doesn't really matter how much torque is made by 3,000 RPM. The converter will flash to the engine's torque peak, which mine should be close to 4500-5,000 RPM with the given duration. Both cars will accelerate the same given the circumstances and equal power. You either dampen power potential up top and limit engine speed (500+ ci, mild-camshaft, airflow requirements hindered by stock port window) or increase power potential (450-470ci with stock port window heads, large duration camshaft, maximize airflow requirements) and shift the power upwards and use the increased engine speed to build more power. With a wider LSA, torque peak will be higher but a small percentage less, in most cases the wider LSA will make a fraction more HP than the tight LSA camshafts (with identical specifications).

I tried to look at every angle in this build, I know many go by 'stall speeds' on a converter, but that isn't necessarily a good indication of reality. In reality, I've had a TCI 10" 3,000 RPM Nitrous Converter in a 302 SBF that wouldn't grab until 1,800 RPM (quite a lot in a car that idled at 700 RPM), would foot brake to 2,200 RPM, and flash at 3,000 RPM. My FTI 9" 4,800-5,000 converter will grab off idle, and drives like a factory car (runs the same as my previous TSI 10" 3,400 converter). Converter manufacturing and techniques (understanding of fluid dynamics in design) has improved dramatically, and also, there is a monumental difference between a low-buck converter and top-tier converter in performance.

It's just bench racing to me, every choice dedicated for a street engine is a tradeoff in optimum performance. I can just tell you it will be a great day when filling up something with this much power, on 87-89 octane (when you're only getting 10 mpg regardless).
 
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i don't get all lost in stall speeds. they're greatly influenced by where the engine makes torque and how much of it.

some years back i used to put together the 470 for some bracket racer friends. we had some "teething" pains at first but after sorting things out it was bullet proof. later we tried a 4.15 crank in the same block; 500 cubes. it didn't run any better than the 470. the two best reliability things we did was the fel-pro 1039 head gasket and cross bolting the center mains (2,3,4). this was an alum rod engine with light weight ross 12.5 pistons, home ported stage 6's, and a comp cams .690 roller. consistent 10.00 car ('67 gtx).
 
Didn't read through the whole thread, but imo: the cam and compression don't seem to jive. 9:1 is dead low. Too low for that cam you have listed IMO. With 78* of overlap in a 260* cam, a dominator flange single plane intake, then 3.55 gears.... I see miss-matched stuff and suspect this combo may be somewhat lazy down low.
If I were tied to 87 octane fuel (which I don't really understand, don't most stations offer at least 90 octane premium??) I'd build a tight quench motor and shoot for at least 9.5:1, if not a little more, and build for midrange torque. A little less cam moved to Wider LSA and tighter converter, and a little more gear would yield better results in my mind. For reference: I run 10.75:1 on pump gas with no issue, albeit 92-octane.

Lastly, I want to make it clear that this is simply my opinion. It's your motor, build what you want and have a blast with it!! :thumbsup:
 
Didn't read through the whole thread, but imo: the cam and compression don't seem to jive. 9:1 is dead low. Too low for that cam you have listed IMO. With 78* of overlap in a 260* cam, a dominator flange single plane intake, then 3.55 gears.... I see miss-matched stuff and suspect this combo may be somewhat lazy down low.
If I were tied to 87 octane fuel (which I don't really understand, don't most stations offer at least 90 octane premium??) I'd build a tight quench motor and shoot for at least 9.5:1, if not a little more, and build for midrange torque. A little less cam moved to Wider LSA and tighter converter, and a little more gear would yield better results in my mind. For reference: I run 10.75:1 on pump gas with no issue, albeit 92-octane.

Lastly, I want to make it clear that this is simply my opinion. It's your motor, build what you want and have a blast with it!! :thumbsup:

Thank you, trust me, I know the combo is mismatched for a drag application, but this car will be running possibly road courses & definitely half mile racing. Has full Hotchkis suspension, 13" front Brembo 'Dr. Diff' / 11.75" Baer brakes, with NT05's all around. Can't physically run any less gear for the MPH I want. Compression was chosen to run 87-pump, but I may change my mind and run 10.77:1 before ordering the pistons. Converter will be its saving grace to get out of the lazy area.
 
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Tim%20Borrall%20440%20078.jpg
I would think for road courses you would want a broad flat torque curve, Kinda like this
 
Is the 1/2 mile E.T. or strictly high M.P.H.
 
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