Mach1 Driver

215x65x15 is 26.0" dia and 8.5" wide, 4.25 backspace (no rub), Brian Conway 215x65x15 " " " " " " 4.50 backspace (no rub) Arning drop and lowered 1.25", Prayers1 225x60x15 is 25.6" dia and 8.9" wide, 4.25 backspace, (no rub) lowered springs, Shep69 225x65x15 is 26.5" dia and 8.9" wide, 4.25 backspace (no rub), Brian Conway 235x60x15 is 26.1" dia and 9.3" wide, 4.25 backspace (no rub) edit: barnett468 has had this on 50+ cars 225x55x16 is 25.7" dia and 8.9" wide, 4.50 backspace, (no rub) Arning drop, nyMustang1969 245x60x15 is 26.9" dia and 9.6" wide, x.xx backspace, (no rub) Arning drop, Ridge Runner Still no word from barnett if any of his 50+ cars had the drop, or Ridge on his backspace

barnett, inquiring minds want to know- did any of those 50+ cars have an Arning/Shelby drop?

OK, good to know. I didn't mean to sidetrack you, that's just the description of the cams. I'm going normally aspirated with a FiTech TBFI. I thought the Crane would give me slightly better idle than the Lunati, since it has 2 more degrees of lobe separation??

I was afraid you would say that ;) You recommended a Lunati 20350711 221/229 .549/.565 112 Hyd roller- mild performance street cam. Needs 5-speed or mild stall in 302 c.ii applications. Requires computer mods. Responds well to increased induction heads and headers. Likes 3.31+ gearing. 2000-6200 rpm What about a Crane HR-220 220/228 .531/.552 114 Hyd roller- good low end and mid range torque and HP, good idle, moderate performance usage, 1600-5600, 2600-3200 cruise rpm, good w/plate nitrous system, 9.0 to 10.5 compression ratio advised. Also good w/supercharger, 20 lbs max boost w/8.5 max compression ratio advised

so no comments on post #28 quench/squish??

I found a 15x7 Shelby with 3.88 backspace- is that about right? This is the tallest and fattest at 26.6 and 9.6

I don't get any hits on "Crane Optical distributor" or Crane P/N 90001500.

Thanks Dave, the site I'm using rounds it off to 1 decimal instead of 2, but otherwise the numbers are the same. Unfortunately none of the sites tell us if they will fit our Mustangs :)

Thanks, we're starting to get quite a list: 215x65x15 is 26.0" dia and 8.5" wide, 4.25 backspace (no rub) 225x60x15 is 25.6" dia and 8.9" wide, 4.25 backspace, lowered springs (no rub) 225x65x15 is 26.5" dia and 8.9" wide, 4.25 backspace (no rub) 235x60x15 is 26.1" dia and 9.3" wide, 4.25 backspace (no rub) edit: barnett has had on over 50 cars 225x55x16 is 25.7" dia and 8.9" wide, 4.5 backspace, Shelby drop, (no rub) it's the second one down and the smallest diameter yet. Any more Shelby drop guys?

OK lets talk about quench/squish. Its the distance between the top of the piston and the head in the flat area surrounding the combustion chamber. Barnett likes .035 to .042. Some forums say .040 to .045 and from one paper by an engine designer he said .040 was the sweet spot. I've been looking into the stroker kits and like the Eagle 14129. I want to keep the compression close to 10.0:1 so I'm looking at their dished pistons. At eaglerod.com they have a neat compression calculator. If I enter the data it looks like this for 351w/408: deck height 9.500 bore 4.030 stroke 4.000 rod length 6.250 chamber vol cc 58 gasket thickness 0.066 piston dome vol cc -20 pin height 1.245 compression 10.01:1 deck clearance 0.005 if you add the deck clearance and the gasket thickness you get 0.071 quench. I can get the quench down to 0.045" but the compression goes up to 10.57:1. I guess my question is- how important is quench, especially since I'm using dished top pistons? You just about need custom pistons to hit this number and get the compression you want.

thanks, that's very Interesting- look at the numbers: 215x65x15 is 26.0" dia and 8.5" wide, 4.25 backspace (no rub) 225x65x15 is 26.5" dia and 8.9" wide, 4.25 backspace (no rub) 235x60x15 is 26.1" dia and 9.3" wide, 4.25 backspace (may rub) 225x55x16 is 25.7" dia and 8.9" wide, 4.5 backspace, Shelby drop, (no rub) I checked these twice because I couldn't believe that the 15s have a bigger diameter than the 16. Well your tires are shorter by 0.3", and in the middle range of widths, and who knows what 0.25" more backspace is doing. It would be appreciated if more of you "Shelby drop" guys could give your wheel/tire sizes. Thanks

hmmm....not your father's Oldsmobile!

I get that you wouldn't have said it unless they had claimed it- and I appreciate that. Probably some over zealous marketing person. Their tech line says that all their ignition controls give it up at 3k. Pertronix seems to be another story---however it is buried in the distributor and doesn't have a clean tach output. Since I'm going to turn all timing control over to the FiTech that doesn't work for me. But if they can do it so can others, so I'll keep looking.

Very nice, you're giving me muffler envy! I notice you have coil overs- can this be done with leaf springs? Seems like it might work if they went straight back instead of dumping behind the wheels. I wonder if the axle would hang down more with leaf springs when it is up in the air?

The only reference to sparking on their website is under Capacitive Discharge Ignitions: The one short coming of a CD ignition is that the spark has very short duration. This isn’t a problem at higher rpm, but could be a lower rpm. However, engineers found that with the increased voltage and nearly instant recovery, the spark can be fired multiple times on the same cycle, hence multiple spark ignitions (or multi-strike, or second strike, etc…). At an idle there may be five or six sparks, and as rpm increases, the number of sparks decreases. Generally, most CD ignitions produce multiple sparks through about 3,000 rpm. Keep in mind that we’re discussing cycles that occur within milli-seconds! I can find no claim that the 6AL2 fires multiple sparks above 3k. I think its the physics of the thing- you can't charge the caps quick enough. I found this on another site: http://dtec.net.au/Multi%20Spark%20Ignition.htm Time Constraints on Multi-sparking: There are time issues and processor loading considerations when implementing multi-spark (time to calculate it and actually effectively do it). The burning mixture can be drawn away from the plug by turbulence and if fresh un-combusted mixture is present it may be ignited with another spark. Research has shown that the sparks needed to be less than a couple of degrees apart to work effectively (you can see now where time issues start arising) If you start to consider the relationship between degrees, time and rpm you can understand the time constraints imposed. At 1000 rpm the crank travels 6 degrees in just 1ms (this may well be the time required to charge the coil up again). 1 degree pass’s in just 0.17ms! Its obvious multi-sparking can only be effective at very low engine speeds. With a 2 degree crankshaft window of opportunity to actually lite the mixture (If I did my math correctly) this would give you .111ms at 3000 rpm for a second spark, and of course it only gets shorter as the rpm goes up. So if someone is doing this I sure would like to know who.

To summarize your thread: with a 4.25 backspace 215x65x15 and 225x65x15 don't rub. Barnett468 says lots of people run 235x60x15 but you have found some that say they rub. FYI from tiresize.com/calculator: 215x65x15 is 26.0" dia and 8.5" wide (ok) 225x65x15 is 26.5" dia and 8.9" wide (ok) 235x60x15 is 26.1" dia and 9.3" wide (may rub) That being said, does anyone know if any of these would work with the 1" Arning drop?

Does anyone know if with 15x7 Magnum 500's and 235x60x15 tires you can still do the Arning/Shelby Control Arm Drop on a 69?

I found this on Crane's website: Multiple Spark Duration 20 degrees crankshaft rotation below 3,000 RPM. Max 12 sparks per sequence with 1 millisecond interval between sparks. Does anyone know of an ignition box that gives multiple sparks above 3k?

Dave I Googled that number and didn't get any hits- are you sure it isn't a D669Y?

agreed

Hey Sam, nice to see you back. I'm no help with the fork, but the big blocks start with the 390. A stroked 302 or 351 is still a small block, even though the new displacement may be over 400 cid.

Rereading that I did imply 15% ethanol, so amended it to say gas, thanks. So the question still remains- is 10.7:1 too high for 93 octane pump gas with 10% ethanol? Anybody out there run that combination? I read that 10.0:1 is the max you should go. I'm thinking your suggestion of custom RaceTec** pistons is still the way to go unless someone has experience indicating otherwise. ** your post said "Race Rech"- can I assume you suffer from fat fingers as I do? I think Rsanter had a good suggestion- take the engine out, set it aside and build another engine that is a stroker. I think I'll do that and also set the FMX aside. I'll have to read-up on how to preserve them properly. On the other hand there doesn't seem to be much demand for a numbers matching 351w car. The big bucks go to big motors.

Thanks fvike, that's very nice, and the video shows it all with engine, cockpit and pipes. We have 10% ethanol added here- do you also? I found this about ethanol blends: Ethanol has high octane and a strong cooling effect when it evaporates so it is inherently detonation resistant... BUT it also has lower energy value so the same quantity of ethanol will result in a leaner mixture compared to gas. The lean mixture can cause detonation despite the higher octane. A carb perfectly tuned for gasoline will need bigger jets to dial in A/F ratio with ethanol or ethanol blended fuel. Most setups are "close enough" to switch between straight gas and 10% ethanol blend gas but higher percentages of ethanol can throw off the A/F mixture a lot. Bigger jets would be needed for E85. FYI, E85 is 15% gas. I'm curious if anyone with a stroker here in the states has any issues with 10%? Most of the independent testing agencies have come out against E85 because it destroys fuel system components.

Sorry no help on the cpp box, but I'm curious why you don't want long tubes? I thought they were supposed to make it breathe better. Which engine do you have? We may have similar builds and headers will be one of my problems with a 351w and 4R70W trans.

Thanks again- I know you give rock solid information. It hasn't been driven much in the last 25 years (that's a long and truly tragic tale)...but if I could make it a daily driver again then maybe I would drive it 10k per year. At only 50k it would last less than 10% of its age (hey everything is relative- I bought this thing when I was a pup). I know LS1s in C5s that have over 200k on them (good old Mobil 1). Yes I know, I should put a LS1 in it. I have a Toyota with 150k on it- yes I know, there's no comparison. The newer motors and technology have spoiled us. If you want the old cars and lots of horse power you have to deal with the consequences, but dang it I don't have to like it! So you've given me lots to think about and research :) More questions will ensue.