4.6L "Poor Mans" Questions

[gradon]

P5249464 valve springs
P4452032 retainers
P4529218 keepers
are the mopar answer to high lift cams(up to .525")
Getting the block milled can be anywhere from $40-100 depending on shop.
With a high DCR of 8.43:1, I don't know if you'll get away with 89, but you'll definitely be okay on 93.

[go4lo]

Ok, I think I'm about to get a handle on all of these variables. I would like to order some parts this week. Of these 3 combos what you guys think would be the best for a daily driver/weekend wheeler?

Combo 1
4.7L +.060
Bore: 3.935"
Stroke: 3.895"
Combustion Chamber: 57cc
Deck Clearance: .0095"(.020 milled off deck w/KB944s)
Gasket Thickness: .044"
Gasket Bore: 4"
Dome/Dish/Valve: 21.7cc (KB944s)
Connecting Rod Length: 6.123" (stock 4.0L)
Cam Intake Dur: 253.3* (Stock 4.0L HO)
Cam Lobe Separation Ang: 114.3*(Stock 4.0L HO)
Advance or Retard: 0* Advance (Stock 4.0L HO)
SCR 9.66:1
DCR 7.97:1
Quench 0.0535

Combo 2
4.7L +.060
Bore: 3.935"
Stroke: 3.895"
Combustion Chamber: 57cc
Deck Clearance: .0095"(.020 milled off deck w/KB944s)
Gasket Thickness: .044"
Gasket Bore: 4"
Dome/Dish/Valve: 21.7cc (KB944s)
Connecting Rod Length: 6.123" (stock 4.0L)
Cam Intake Dur: 250* (Comp Cam 68-232-4)
Cam Lobe Separation Ang: 113*(Comp Cam 68-232-4)
Advance or Retard: 3* Advance (Comp Cam 68-232-4)
SCR 9.66:1
DCR 8.28:1
Quench 0.0535

Combo 3
4.7L +.060
Bore: 3.935"
Stroke: 3.895"
Combustion Chamber: 57cc
Deck Clearance: .0095"(.020 milled off deck w/KB944s)
Gasket Thickness: .044"
Gasket Bore: 4"
Dome/Dish/Valve: 21.7cc (KB944s)
Connecting Rod Length: 6.123" (stock 4.0L)
Cam Intake Dur: 262* (Comp Cam 68-239-4)
Cam Lobe Separation Ang: 111*(Comp Cam 68-239-4)
Advance or Retard: 4* Advance (Comp Cam 68-239-4)
SCR 9.66:1
DCR 8.13:1
Quench 0.0535

[Cheromaniac]

You're very close to the 4.7L medium buck recipe from my site.

[live24wheel]

Can I ask why your not inquiring about the Comp 68-231-4? Just wondering as im building basically the same setup and that cam sounds pretty common.

[go4lo]

You're very close to the 4.7L medium buck recipe from my site.

Yep...I'm trying to base it off your recipe. In your opinion which set up would you go with?

I know you recommend the Comp 68-231-4, which was my first choice, however when I run the numbers on the calculator with that cam it bumps my DCR up to 8.43:1, which from my research is not the target number with a quench of .0535. Too get the DCR down I have to put in one of the other Comp Cams.

What are you thoughts on this? Would I be forced to run 93 with that DCR?

Thanks

[go4lo]

Can I ask why your not inquiring about the Comp 68-231-4? Just wondering as im building basically the same setup and that cam sounds pretty common.

See my response to Dino above.

[go4lo]

Anyone?

[gradon]

All I can tell you is my dcr is 8.57:1, 10:1 scr and I am running the 4.2 rods and h802cp30 hyperteutic pistons that are .011"-.0125" below deck, I'm using a .051" HG, and have to use 93 octane. Your original combo is 8.43dcr, you're using the 4.0 rods which will have a longer dwell time at tdc(means less potential for ping), and your quench is going to be .010" better than mine. I say go for it. I did port and polish my head, so my combustion chamber is smooth.

[Cheromaniac]

Yep...I'm trying to base it off your recipe. In your opinion which set up would you go with?

I know you recommend the Comp 68-231-4, which was my first choice, however when I run the numbers on the calculator with that cam it bumps my DCR up to 8.43:1, which from my research is not the target number with a quench of .0535. Too get the DCR down I have to put in one of the other Comp Cams.

What are you thoughts on this? Would I be forced to run 93 with that DCR?

Thanks

I don't think so. With that tight quench you should easily run 91 octane if not 89. Make sure the combustion chambers and piston crowns are smooth, optimize the fuel curves, use a 180* t'stat, and make sure the cooling system is up to scratch. These measures will reduce the risk of detonation and increase your chances of running lower octane fuel.

[go4lo]

Hey guys I plan to order some parts tomorrow including the Comp Cams 68-231-4 as discussed earlier as well as the Mopar Performance springs, retainers and keepers and new stem seals. I have a few questions before I place the order.

What lifters should I go with?
What push rods with .020 taken off the block?
Anything parts I'm missing for the head?

FYI - My head is casting 0630.

[SilverXJ]

Johnson Hylift/Topline toplineauto.com, 800-441-1400.

As for pushrods, until you get it assembled and measure for pushrods your are guessing at what pushrods you need. If you really want to go the guessing route call Smith Brothers Pushrods. They should be able to hook you up. http://www.pushrods.net/

[go4lo]

Johnson Hylift/Topline toplineauto.com, 800-441-1400.

As for pushrods, until you get it assembled and measure for pushrods your are guessing at what pushrods you need. If you really want to go the guessing route call Smith Brothers Pushrods. They should be able to hook you up. http://www.pushrods.net/

I think I may just go with the cam and lifter package that Comp Cams offers. Any reason why not to?
I noticed in your thread you groved the lifter bores can you give me some more insight on that?

Regarding the push rods...yes I will need to wait until I get it assembled, I was just looking for suggestions.

Thanks