Astro engine is using the 20350711 Cam you detailed above. For comparison it is a milder (meaning ramps are a little less aggressive) version of the XE274HR that I installed into Cages engine.
The 20350712 is what we selected for the 408 build - very mild cam for that size of engine though it works very well (both performance and towing [which was one of the goals]). It would be fine for your injected 347, the only sticky point is the stall converter - you would really need round a 3000 rpm stall speed.
You do need decent springs though - XE and voodoo lobes are still fast so needs some decent spring to control them. Also remember because the ramps are fast you get more area under the curve so even though intake duration of 221 verses 220 might appear about the same - you will find the voodoo is much larger (without any overlap complications) than your current grind.
I would stay with the 20350711 voodoo (or similar like the XE274HR) or go with something in between. When I was discussing Cams with Trav for his 347 I suggested something between the two sizes. He went one minor step closer to the 230 duration - it works very well for him. If you like I can suggest a combination if your interested. I do tend to prefer fast ramps, high lift short duration minimal overlap cams so I may not go close to the 230 intake more likely 225 and around 0.6 inch lift.
I will someday think of something clever to say.
Last edited by boofhead on Thu Dec 10, 2015 9:29 pm; edited 5 times in total
If you like I can suggest a combination if your interested. I do tend to prefer fast ramps, high lift short duration minimal overlap cams so I may not go close to the 230 intake more likely 225 and around 0.6 inch lift.
Realistically I won't be able to do it any time soon. I'll start a thread if it ever looks like becoming a reality.
I really like the Lunati we put in dads 351C.
I'm not 100% sure of my spring rate actually.
All I know is they are 1.437" dual springs.
All those cams are ground on 112 centres so would be fine with injection.Rod's 408 is in a 69 fb pretty heavy car compared to a 65 and the 282 voodoo works great idles with a lope at around 850 and will turn sub 12 1/4 mile with a 3.25 diff. 750 demon DP carb and rpm intake. Really the heads are too small, 195 pro 1 darts, and it still a bit a a weapon. The heads were reused due to cost restraints. Stall is supposed to be 2500 but with the torque of the 408 it's more like 3500 I reckon. Car is tame enough as a daily driver fuel use age aside. Would love to do 408 with 205 heads bigger cam and victor type intake not much would touch it.
Sorry I meant the term "cruiser" loosely. Don't doubt it will be scarily fast in real life.
My custom comp (in my 347) is at 228/236, ~0.570" lift and I wouldn't want to go too much bigger on a street car. Definite lope and idle is about as rough as I could handle for for its dual purpose life ( i.e sunday was at track and yesterday was going to shops to collect the milk and groceries haha).
PS: I made good time to the shops too but I think the Bridgestone RE-11 slicks helped!
Good timing WRT resurrection of this post. I've been looking at replacement cams for when I take another go at the 347/363/whatever_size_it'll_end_up and have the Lunati 711 cam written down on a sticky note.
A cobra replica owner in the UK got 450 FWHP using this cam on a 347 with AFR heads. It should work nice with my Brodix.
Travs Cam is running 12 deg overlap @50 thou lift. Hence a little lope though this does provide a bigger punch mid range - so you would really feel the grunt come in around peek torque. Its intake biased though close to a split overlap cam which is great.
The XE274HR has 4 degs overlap @50 thou lift so its idle is reasonably mild - you know it is there and not stock. It is 100% intake biased so it would tend to work better on heads with good exhaust ports (such as AFR provides). If you tighten it up a little say to 110 centers rather than 112 it brings the overlap up to 8 degs @50 thou lift which is helpful if your heads do not flow as well as you know you should have. It brings a little more overlap to assist and bring in a stronger mid range. The change also brings the overlap bias a little back from the intake side only. An EFI car is better to keep overlap smaller to help with the MAP reading at idle while for a Carbi car, tighter is preferred especially if it is a manual car.
The voodoo 20350711 is only 1 deg overlap at 50 thou lift. It is also heavily intake biased so it requires a good exhaust system (relative to the intake). It is a small step back from the XE274HR but not by much so it is often a very good choice for street engines where your looking for bigger than say an XE266HR (which is -4 deg overlap at 50 thou lift and 100% exhaust biased - so a good cam for factory iron heads or weak exhaust ports/systems).
As always, the bigger the engine the more cam it can take for the same behavior. So a 302 with an XE266HR will be similar to a 347 with the XE274HR or a 408 with the XE282HR.
I will someday think of something clever to say.
Last edited by boofhead on Sat Dec 12, 2015 12:50 am; edited 2 times in total
I just had comp cams grind me a cam on a steel blank, price was reasonable but freight was expensive, I had it ground on 110 centres though Woody tells me he normally get them done on 108. I'll try that next time for a laugh, when I do a 363 If I ever do. I,d like to build one with 205 heads, 235 degree cam 108 centres, single plain intake.
Just have to bring myself to spend the loot on a Dart block. Long term project perhaps
Last edited by Shaunp on Sat Dec 12, 2015 11:46 am; edited 1 time in total
SP - your Cam if it was ground on 108 centers would be 12 deg @50 thou overlap.
So for the exercise for your 363, if I used the XFI236HR (as I think it is a good cam for a large EFI stroker) as the base grind. This cam is on 114 centers so it has 14 deg overlap @50 thou. Now on 108 centers it is 26 degs of overlap @50 thou. NICE!!!!!! Lumpy. Old school. (Note: Need a big engine - do not do this on a 302).
Next time you talk to woody, find out if you can what advance he uses - Comp is normally 4 deg so I would be interested in if woody varies the advance at all. I have been paper experimenting looking at the effects from changing the ground in advance on the cam timing numbers.
I think with a 4.125 bore the engine would tolerate a fair bit of cam , more so then a 351 with a 4.030 bore. The vac created by the much larger bore would create much higher gas speed. So to my way of thinking you can go up in cam and port size, without loosing any drive ability . I think the 363 package would easily out perform a similar size 351, at most if not all engine speeds. I,m really keen to go there one day, I think they are likely the best early mustang pre 69 package, compact and plenty of power
Last edited by Shaunp on Sat Dec 12, 2015 12:55 pm; edited 1 time in total
A 347 (8.2 deck) build verses a similar 351 (9.2 deck) build will always result in the 347 being the superior performer. The 351 disadvantages are, larger engine, heavier block, heavy crank, heavy rods, heavy pistons, large bearing fictional surfaces. So it is always an easy choice ..... until you want lots more power (say 500+ FWHP [this is a rough guide]). Then your looking at a stroked 408/418 which allows more HP because the 351 base is stronger up to 700 FWHP [this is a rough guide also].
The dart blocks address any strength concerns (for street builds) as they are rated to 1000 FWHP [this is a rough guide]. So the 8.2 deck is the go for early 65/66 mustang for sure as they are the best choice for a high HP option - 363 (or bigger) easy HP.
For later cars, I tend to jump to the 9.2 deck because you are looking at 427/438 engines with the Clevo bearing sizes removes the frictional surface concerns for higher rev applications. Street engines are best big so it is easy power. Highly strung motors are great hence this thread but average guy is really better off with a plan that has big capacity engine without going to high in the rev range (restrict to 6500 rpm).
Yep the 3" Windsor 351 main bearings are a power killer, strong though. Hence why a 351 really needs a stroker crank I discussed this with Astro early on but he was happier with the 351 over a 347 due to the stronger base engine and didn't think he needed the extra power of a 393 or 408 . In real terms it will out last all of us I guess and still be quicker than his Holden sports wagon if the tyres hook up.
Last edited by Shaunp on Sat Dec 12, 2015 2:41 pm; edited 1 time in total
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