• 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5
351c should i keep 2v
#1
hey guys i have had this worry in my head on what i should do with my motor. my 73 mach is undergoing a restoration which will be awhile. I rebuilt the 351c 2v awhile ago with a tight budget. since then i have picked up a nice set of 4v cc and a standard bore block. At first i was going to run the 2v if i wanted more power i would build the 4v to swap in. here are the basic specs off the top of my head on the 2v
bored .040 over
crank turned .010
line bored
heads planed .010
flat top pistons
3 angle valve job, port matched, new valves, springs, seats
full msd
holly 650 dp
2v street dominator
crane cam .524 lift cant remember the duration was a popular cam non-split

my issue i guess is i would like to be in the 400hp at the crank range but i don't know how close this combo would be. I will be going back into the engine to change a few things i didn't do because of money. while I'm there should i put the 4v heads on it and buy a intake or should i leave it be a run it as is. I'm not looking for a high hp motor i just want it to be respectable and not be wimpy. tell me what you think i should do and what mods should i do to the motor while im in it. (oil flow mods, arp goodies, roller rockers, double roller chain, aftermarket water pump) thanks in advance guys i have never drove my car before so i have nothing to go off from.
  Reply
#2
Go for it. The extra compression will help. Slip in a higher speed torque converter.

Someone will tell you .40 overbore is too much. I have the same setup and no issues (cooling or otherwise) at all. Not all of the blocks were good for .40 but if your engine guy checked it out and he knows what he is doing you should be fine.

'Mike'
73 Convertible - 351C/4V CC heads/4bolt/forged flat tops/comp 270/rhodes/mallory unilite/tri-power/hookers/glasspacks/c6/3.50 limited slip/Gear Vendors/Global West sub frames, strut rods and shelby style traction bars/ Rear sway bar/tilt steering (not original)

Pics of modifications included in:
  Reply
#3
Without knowing what your compression is now. I'm not sure you want to go the closed chamber route with what you already have. Any idea what it may be?

[Image: 2rr7aiv.png]

Just cruising along minding our own business when BAM!!! The LAWS show up.
  Reply
#4
we did not calculate compression on the engine my engine guy who chose the pistons for me said with the heads being cleaned up .010 he said i would be right around 10:1 - 10.5:1 . these are flat tops the block was not decked. I have heard most guys run flat tops with the closed chambered 4v heads. That is the main thing i was questioning if i could run the same pistons if i were to swap heads. does anyone have any issues with header clearance with the 4v with power steering?
  Reply
#5
Your compression ratio will probably go up to between 11:1 and 11.5:1. My other concern is the valve reliefs in the pistons and valve clearance.



“If you can't explain it simply, you don't understand it well enough.”
--Albert Einstein
  Reply
#6
I'd leave the 2V block alone, and build a 4V engine with the standard bore block over time as budget permits. Run the 2V, have some fun, then swap in the 4V down the road at some point. Swapping the 4V heads onto the 2V engine might mess up the mix of what you have now... and I'm not entirely sure, but I think pushing much past 10.5:1 compression will move you out of pump-gas territory.

Just a thought.

Eric

[Image: mach1sig2.gif]
  Reply
#7
+1 to what Eric said.

[Image: 386_07_10_13_5_58_42.jpeg]
My Mustangs:
71 M-code Mach 1, Medium Blue/White Sport, 4R70W, 3L50, Factory Ram Air.
72 Q-code Mach 1, Pewter/Black Sport, 4-spd, 3L25.
65 Convertible, Britney Blue/White/White, more modified than original.
05 Convertible, Legend Lime/Tan/Tan, future classic??
  Reply
#8
You will need a different intake... the 2v intake will not work with 4v heads.

Jeff T.

Low buck, touring style, '73 Convertible "rolling restoration", 351c, 2v heads with a shave and a haircut, Performer intake, Holley 650(ish), roller rockers, screw in studs, guideplates, stainless valves, Duraspark / Motorsports MSD, T-5 conversion. 1-1/8" front, 3/4" rear swaybars KYB shocks and some home brewed subframe connectors. Future plans; JGC steering box, Cobra brakes and... paint, interior, etc.

When I die I want to die like grandpa, peacefully in my sleep... not screaming, like his passenger.

[Image: 1_12_09_14_10_15_11.png]
  Reply
#9
thanks guys for the advice. I know i would need to pick up a different intake for the 4v heads plus headers. I think I'm going to stick with the 2v and do what eric mentioned build a 4v over time then if i want i can swap it in. As far as the 2v motor is there anything you guys would do as far as upgrades to the oiling system, valve train. I know a lot of guys put in restrictors and lines to the mains. Is it needed on a mild motor? anyone have a guess of what hp this 2v setup would be around? thanks ryan
  Reply
#10
You don't need to do any oiling upgrades to a 2v (and most 4v) if you don't spin them too high.

'Mike'
73 Convertible - 351C/4V CC heads/4bolt/forged flat tops/comp 270/rhodes/mallory unilite/tri-power/hookers/glasspacks/c6/3.50 limited slip/Gear Vendors/Global West sub frames, strut rods and shelby style traction bars/ Rear sway bar/tilt steering (not original)

Pics of modifications included in:
  Reply
Share Thread:  


Possibly Related Threads...
Thread Author Replies Views Last Post
  difference in 351C-2v heads Vinnie 6 207 09-06-2018, 03:37 PM
Last Post: Vinnie
  Increasing Power 73 351c Cobra Jet bytor2112 4 197 09-05-2018, 05:33 PM
Last Post: Carolina_Mountain_Mustangs
  351C fuel pumps? Hemikiller 5 251 09-02-2018, 07:12 AM
Last Post: clevelandcoupe
  1973 351C vacuum lines and eventual other questions scottyrocks 14 475 08-12-2018, 11:53 AM
Last Post: Don C
  Correct 351C Power Steering Hoses? street rod mach 1 7 293 08-12-2018, 08:26 AM
Last Post: NOT A T5
  351c cam lobe ID. Have to measure lift Ryunker 8 398 07-23-2018, 06:04 PM
Last Post: Ryunker
  351c vs 351w Tnfastbk 11 6,037 07-14-2018, 02:57 AM
Last Post: MissingNo.
  Holley Sniper on a 351c Fabrice 45 6,220 07-01-2018, 01:54 PM
Last Post: Fabrice



Users browsing this thread: 1 Guest(s)