I don't see where valve size has anything to do with clearance. My 1.72's clear on GT40 heads with oversize Manley Proflo valves and stock valve covers.

 

hmm, sounds like i should place another call into afr. i wasnt thinking about that when i talked with them earlier, they said you have to have valve reliefs in the pistons with those heads. maybe the e303 with 1.6 RR is going to be a better safe bet.

 

I would try and get .040 squish if possible...it help's on detonation among other things. .030 - .040 is ideal.

 

well .043 thickness should squish down to about .040 so i think ill be good there. i do want this to run on pump gas since ill be driving it alot so keeping the compression around 10.5:1 isnt necessarily a bad thing, is probably actually better for what ill be doing. i still need to find a intake manifold and plenum that will flip around since the crown vic's throttle body points toward the drivers side unlike a mustang. if this thing will really make over 400 ft lbs of torque at 2000 rpm i think there will be no acceleration problems lol. i look forward to seeing what conanskis DD comes up with as well for comparison

 

Ok like i said i dont know ..I just heard with the 202 valves with 1.72 rockers there can be a clearence problem with some cams on the stock 5.0..I just wondered if that is true . But if your ok then i guess that ansers my ?? Valve size dosnt make any difference ..Lew

 

Torino I ran on another simulation dyno program called VD (different than DD) and I come up with higher horsepower and about the same torque. It showed 458lbs at 3000rpm peaking at 483lbs at 4250 with maximum horsepower peaking at 486 at 5750. This program takes a few more factors into the equation, but I am still leaning toward the DD numbers, but again, proof that the DD numbers can't be far off.

It also shows....based on those numbers....
4,000 lb vehicle + 200 lb driver = 4,200 total..
1/8 et - mph 8.05 @ 85.76
1/4 et - mph 12.56 @ 107.20

Rear wheel HP and Torque 384lbs @ 4,000rpm, and 388rwhp @ 5,750

For what it's worth....thought it was interesting anyway.

 

sounds very good and i appreciate you looking at that stuff for me. well, im commiting to building this 347 now thats for sure. its going to take some time to get all the parts together obviously. first thing im looking for is a mustang mass air ecm and wiring harness. im going to save as much money as i can before i start buying the pricey parts, that way i know i wont run out of cash before the build is finished. the real progress will probably be starting mid summer but ill keep updating as i go. every hp and tq estimate i get brings a grin to my face lol..if i could break into the 12s that would be amazing..

 

ok, so the piston head volume on the kit i mentioned, on summits spec sheet it says its +5cc and is a flattop piston with two valve reliefs. now i was looking at a forged piston instead that would fit on the rods, and it says it has a +11c piston head volume with four valve reliefs instead of two. so i was wondering if you could figure out what the compression ratio would be with the +11c piston head ?with the 60cc combustion chamber in the head. i was thinking when calculating compression ratio wouldnt you plug in -11cc? since its a flattop piston with valve reliefs? cause i have this online compression ratio calculator but im not sure what numbers to plug in for the piston head volume. i need some help on this part

heres the piston spec sheet to give you what it says exactly

http://store.summitracing.com/partde...D&autoview=sku

 

FOMO . On your build your runing the X cam & gt -40 heads with 1.72 rockers .. What size valves are you using & are they pedestal mount or stud mount . Whats your head cc & comp ratio . ??? & what kind of RPM are you turning.. Lew

 

forget everything i said in that post. after a couple more hours of reading im going to use the hypereutectics in the kit, since i wont be spinning this motor anywhere past 6500rpms. also, just for anyone curious hypereutectic pistons can handle a mild amount of boost (less than 8 pounds), and a small amount of nitrous (less than a 150 shot). and they arent good for revving past 7500 rpm. so, in short i think hypereutectics are all i need. it seems like the only people that have problems with the hypers are either putting too much boost on them, too much nitrous, spinning really high rpms or have a crappy tune.

if i remember correctly the gt-40 heads have a 64cc combustion chamber.

 

You actually add +5cc or +11cc when calculating the compression ratio with fly cuts as you now have more volume in the combustion chamber. If you have dome tops it would be - cc's as you are taking away compression space. Hey check with the guys at T&L Engines in Charlotte N.C.. I used coated Speed Pro Hypers and they did custom flycuts on mine in their machine shop. I also got the whole stroker package from them and they did the balance work and everything. VERY reasonable. They also have a dyno and build full turn key engines to sell and for Nascar teams. Check 'em out on the web.

Lew....the GT40's have 64cc chambers. I had Manley ProFlo 1.94/1.60 valves installed and I did all of the port work. I have never had them flowed so I am using conservative numbers, but check out these numbers on a set flowed with the same valves. I'm sure my port work is probably not quite as good, but I made most of the same cuts. If I am flowing anywhere close to these numbers I am actually closer to 400h.p. I have not started my motor yet...I have RCI aluminum fuel cell left to install and plumbing for that. I have to install a flexible lower radiator hose, and put on my serpentine belt. Then the moment of truth. Oh, and I am also installing a Air Inlet Systems Dual 4" Ram Air Intake (try to get the most part of it done tomorrow). Here are the flow numbers that I spoke about and some pics of my motor and rebuilt c4 when I was sitting it the frame rails. I am pretty sure I am at least 360 on the low side and 400 on the high side.

Bottom numbers is ported with the Manley RaceFlo/ProFlo Valves

CFM flow chart

---------+--------+--------+--------+--------+--------+--------+--------
Valve | | | | | | |
Lift | .100" | .200" | .300" | .400" | .500" | .600" |
---------+--------+--------+--------+--------+--------+--------+--------
stock | | | | | | |
intake | | 111 | 159 | 183 | 185 | 190 |
---------+--------+--------+--------+--------+--------+--------+--------
#1 prting| | | | | | |
intake | | 115 | 166 | 193 | 208 | 210 |
---------+--------+--------+--------+--------+--------+--------+--------
1.94 prtd| | | | | | |
intake | 98 | 156 | 207 | 225 | 237 | 242 |

CFM flow chart

---------+--------+--------+--------+--------+--------+--------+--------
Valve | | | | | | |
Lift | .100" | .200" | .300" | .400" | .500" | .600" |
---------+--------+--------+--------+--------+--------+--------+--------
Stock | | | | | | |
exhaust | | 28.5 | 125 | 129 | 129 | |
---------+--------+--------+--------+--------+--------+--------+--------
#1 Prting| | | | | | |
Exhaust | | 101 | 142 | 172 | 174 | 173 |
---------+--------+--------+--------+--------+--------+--------+--------
1.6 prtd | | | | | | |
Exhaust | 127 | 155 | 178 | 195 | 203 | 203 |

(The comments below reflect the mods made with the 1.94/1.60" valve install)

* The final porting of the GT40 iron head in which 1.94/1.60 Manley
Race flow valves were used resulted in truly great flow numbers.
The large Manley valves appeared to aid both the intake and exhaust
significantly, with the exhaust gaining the most as predicted
due to an inferior small 1.54 valve for the port size and bowl
area after porting the 2nd time around. The Short-side radius
turn on the exhaust also was laid back perfectly this time
with a slightly decreasing radius from the valve job to the exit.
The exhaust port floor was untouched and the roof extensively
modified esp around the critical guide and thermactor hole locations.
The combustion chamber was lightly worked around it's outer edge to
eliminate any rough edges and lips that might hurt low lift flow.

* The Intake port on the 2nd porting with the 1.94" valve installed
was simply a bowl widening on the short turn port "wall" (not the
floor) and smoothing of the radius. After that operation, the bowl
was opened up and blended with a bottom cut for the larger valve.
The bottom cut left a rough edge and also made the narrowest point
in the intake port valve throat area. The 242cfm # was with this
rough spot still on the casting. It was later removed and the
bowl hand-blended (opened another .030" in radius), but it was
never reflowed. Thus it is surmised that the GT40 iron will go to
over 242cfm (maybe 250-260cfm).

* No special cuts were used on the intake valve which was a bone
stock Manley Race flow valve.

* Note the extremely high low lift exhaust flow #s. This is excellent
or ideal for a forced induction motor and even the killer low lift
intake flow is outpaced by the incredible exhaust flow from
.100" to .300". Also note the high intake to exhaust ratios throughout
the entire lift range.

* The extremely high low lift flow #s on both the intake and exhaust
and the high intake to exhaust ratios may require a revised camshaft
profile to take into account that the overlap period may have
substantially higher scavenging or reversion effects given the
increased low-lift flow over the unported heads.

 

ok. well since you said with the +5cc pistons ill be somewhere around 10.5:1 to 10.8:1 compression ratio area depending on which gasket thickness with the 60cc combustion chambers? ill stay with that known combination since it should run good there on 93 octane pump gas. your engine looks good sittin in the chassis too by the way

 

What is the compression height on the pistons you're going to be using?

 

Check this out from T&L...



Not bad for $4K and piece of mind. Heck you can tie up $4k in a hurry...especially if you spend $1500 on a set of heads and $1500 on a stroker package.

* ENGINE MODEL - 347 A2
* HORSEPOWER - 430 HP
* TORQUE - 430 FT LBS
* BORE AND STROKE - 4.030 X 3.400 Inches
* COMPRESSION - 10:1
* FUEL - Premium pump gas
* CRANKSHAFT - Cast steel
* CONNECTING RODS - Forged I beam, bushed
* PISTONS - Hypereutectic
* RINGS - File fit plasma Moly
* BLOCK - Ford 302 roller block, one piece rear seal
* CAMSHAFT - Comp Cams hydraulic roller
* DURATION - 224 IN / 230 EX at .050
* LIFT - .556 IN / .515 EX with 1.6 rocker
* LIFTERS - OEM style hydraulic roller
* TIMING SET - Double roller chain
* TIMING COVER - New aluminum
* HARMONIC BALANCER - Professional Products
* OIL PUMP - Melling standard volume

* OIL PAN - Stock style chrome (front or rear sump)
* HEADS - 195cc Dart Pro 1 Platinum
* HEAD BOLTS - ARP
* VALVES - Stainless Steel 2.02 Intake 1.60 Exhaust
* SPRINGS - Dual with dampner
* ROCKER STUDS - ARP 7/16 diameter screw in type
* ROCKER ARMS - Aluminum full roller, 1.6 ratio
* PUSHRODS - 5/16 Hardened steel with guide plates
* INTAKE MANIFOLD - Aluminum Edelbrock RPM Air Gap
* VALVE COVERS - Chrome stamped
* SPARK PLUGS - Autolite 3922
* OIL FILTER - Fram PH5 or comparable
* IGNITION TIMING - 32 degrees at 4,000 RPM
* OIL TYPE - Shell Rotella T 15w-40 recommended, synthetics not recommended


LABOR DETAILS

* All parts hand cleaned
* Block sonic checked for thickness
* Block pressure tested @40 psi
* Block stroker clearanced
* Block square decked w/BHJ fixturing
* Oil gallies tapped for screw in plugs
* Aligned hone mains
* Bored and honed w/torque plates

* All clearances checked to the nearest .0001”
* Rotating assembly balanced
* Engine blueprinted w/specs sheet on file
* Engine fully assembled and dressed to customer specifications
* Dyno tested with actual results supplied to customer
* DVD of dyno session supplied to customer
* 1 year 12,000 mile warranty


UPGRADE OPTIONS

* Forged pistons - $289
* All Forged (Includes 4340 crank, 4340 H-beam rods, and forged pistons) - $600
* Solid roller camshaft and lifters - $211
* Extra capacity oil pan upgrade - $225

* Ford Racing valve cover upgrade - $119
* Dart Sportsman block upgrade - $2,000
* Mass-Flo Mass Air Fuel Injection System - $2,995
* Other upgrades available. Please call or email for pricing.

 

how do i find that out? the kit doesnt say what the compression height is