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Help me build a 4.7L 300hp/300+lbft TorqueRRR

Posted: March 6th, 2018, 3:11 pm
by darkartz
After 9 months of extensive reading build threads, watching build videos and carefully tearing apart my 290000km stock 1995 4.0L RHD XJ Sport, I have decided to build a 4.7L stroker in Australia. After all the reading I have a fair idea about how things work and how they should to be put together. However, I have deficiencies in knowledge in some areas of this stroker build to reach my exact goal. Given that I live in Australia, down under, and all my parts are being freighted from USA and shipping costing an arm and a leg, I have pretty much a 0% tolerance for error in this build as returning parts is not an option. So i need some expert input in determining appropriate parts and specs.

Estimated SCR is approx. 10.25:1 and DCR is approx 9.5:1

My build's parts list as follows;

-1996 NVH+girdle Block which will be bored to 0.060

-Block will be decked off 0.030"

-Felpro 530SD 0.051" head gasket

-Most likely IC944-060 pistons - yet to purchase

-Hastings 2M667 0.060 Moly rings

-1995 "544" or 1996 "691" 4.0L conrods (they are visually different - yet to decide on strength)

-1971 AMC Rambler/Hornet 258ci manual trans 12wt crank shaft #3199738 (0.010/0.010 under) - Snout shortened and rear flange has been modded to fit the AW4 Auto trans and the flex plate using a custom pressed in adapter.

-1995 #7120 H.O. DIY ported head - Intake (avg) - 1.95"x 1.5" = 2.9+ sq inch / Exhaust - 1.71" x 1.46" = 2.5+ sq inch (these values are beyond Dino's site's DIY values, yet to experience the effects)

-Head will be milled off 0.020"

-Intake valves - yet to decide between stainless steel or stock replacement

-Exhaust valves - yet to decide between stainless steel or stock replacement

-Felpro premium valve stem seals

-Valve guides - Manganese bronze if stainless steel or stock integral guides if stock valves

-Valve seats - Cr-Ni hardened seats for stainless steel valves or even stock replacement valves

-Most likely Comp Cams 68-232-4 or 68-231-4 nitrided camshaft - yet to purchase

-Crower cam saver lifters

-Push rod length - yet to determine and purchase

-Mopar P5249464 + P4529218 + P4452032 Spring, retainer & lock combo

-Yella Terra 1.6 or 1.7 roller rockers - yet to decide and purchase

-Dual roller timing set - yet to purchase

-2003 TJ wrangler newer style intake manifold - ported

-70mm throttle body - 505 performance - yet to purchase

-1995 return style fuel rail

-Delphi FP10046 fuel pressure regulator - 40psi Idle/ 48psi WOT

-Ford motorsport M9593-LU24A 24lb/39psi 6 hole injectors with EV6 adapters

-Exhaust manifold - yet to decide & purchase

-All ARP hardware - Studs instead of bolts wherever possible

-All MOPAR sensors

-MAHLE/Clevite all tri metal bearings

-Flowkooler High flow water pump

-HESCO high flow thermostat housing

-195'F standard flow Stant thermostat

-3 Core Fully aluminum/ alloy radiator with triple electric fans, factory fan delete

-Accel120330 distributor cap

- MSD8228 Ignition coil

-Bosch 9656 Double Iridium Spark Plugs

-9.0mm ignition leads - already on motor

-K&N HP2004 Oil filter

-Melling High Volume oil pump


1). Will i explode on 91 octane unleaded fuel?
2). Will i explode even if i retard the ignition timing?
3). Which is the better cam out of the 2 above for low to mid range torque?
4). Is the 300hp/300+lbft goal unrealistic with this setup?
5). Will I end up with too much cylinder pressure and too thin cylinder walls?
6). Bosch 9656 double iridium - is it too hot?
7). Will i have piston-valve contact with Yella Terra 1.7 rockers?
8). Will I have coil bind on the Mopar P5249464 spring if used 1.7 rockers?
9). 1995 "544" or 1996 "691" conrods?
10). Using a High Volume water pump and a standard thermostat, will I end up with too much coolant pressure?
11). Does the injector + regulator combo suffice my fueling needs or should i upsize the injectors?
12). With the extreme DIY head porting will it negatively effect the breathing?
13). Am I missing any critical bits or is there a better recipe over this to achieve my power/torque goals in a low-mid rpm?

I understand it is a lot to ask for and may have been discussed repeatedly, but any input is highly regarded as local knowledge in Australia regarding Jeeps is way more rare than a hen's tooth.

Regards,
Kasun.

Re: Help me build a 4.7L 300hp/300+lbft TorqueRRR

Posted: March 7th, 2018, 12:57 am
by Cheromaniac
A slight variation on this recipe should help you achieve your goal:

4.7L medium-buck stroker
Jeep 4.2L 3.895" stroke crank
Jeep 4.0L 6.125" rods
Custom forged +0.060" bore pistons, compression height 1.380", dish volume 15cc
10.2:1 CR
CompCams 68-235-4 210/218 degree camshaft
Russ Pottenger ported Edelbrock 60cc aluminum cylinder head
Mopar/Victor 0.043" head gasket
0.043" quench height
Flometrics F&B 68mm billet TB
Accel 30lb/hr injectors for '87-'95 engines
290hp @ 5100rpm, 340lbft @ 3700rpm

Contact Russ Pottenger and discuss a plan of attack with him. He can supply you all the necessary parts in one shipment and that'll save you a lot of money.

Re: Help me build a 4.7L 300hp/300+lbft TorqueRRR

Posted: March 7th, 2018, 1:22 am
by darkartz
Cheromaniac wrote:A slight variation on this recipe should help you achieve your goal:

4.7L medium-buck stroker
Jeep 4.2L 3.895" stroke crank
Jeep 4.0L 6.125" rods
Custom forged +0.060" bore pistons, compression height 1.380", dish volume 15cc
10.2:1 CR
CompCams 68-235-4 210/218 degree camshaft
Russ Pottenger ported Edelbrock 60cc aluminum cylinder head
Mopar/Victor 0.043" head gasket
0.043" quench height
Flometrics F&B 68mm billet TB
Accel 30lb/hr injectors for '87-'95 engines
290hp @ 5100rpm, 340lbft @ 3700rpm

Contact Russ Pottenger and discuss a plan of attack with him. He can supply you all the necessary parts in one shipment and that'll save you a lot of money.


Thanks Cheromaniac for your response. I have got in touch with Russ. He is yet to email me tomorrow.

I was planning to mill and deck the block and head (0 or - clearance) and let the thicker Felpro head gasket make up the quench. I thought a thicker gasket would give a better bite when torqued down as opposed to a thinner MLS gasket when it comes to increased SCR, DCR, Cyl pressures etc.
That way I could use an off-the-shelf piston in case I had to rebuild down the line instead of going custom?

Is the flometrics 68mm a better option over the 505 billet 70mm TB? Any experience?

Re: Help me build a 4.7L 300hp/300+lbft TorqueRRR

Posted: March 7th, 2018, 2:21 am
by Cheromaniac
darkartz wrote:Is the flometrics 68mm a better option over the 505 billet 70mm TB? Any experience?
I've had no experience with either, but the 70mm TB should work for you.

Re: Help me build a 4.7L 300hp/300+lbft TorqueRRR

Posted: March 7th, 2018, 2:28 am
by darkartz
Do you know about the geometry and the limits involving the Yella Terra 1.7 rockers and the Mopar springs?
Will i subject to coil bind if i were to use 231, 232, 235 cams?

I read somewhere the spring is only good up to 0.525". A 0.3" cam lobe lift with a YT1.7 brings it up to a 0.51+". Safe enough?

Re: Help me build a 4.7L 300hp/300+lbft TorqueRRR

Posted: March 7th, 2018, 7:19 am
by Cheromaniac
Yup. The P5249464 springs are indeed rated to 0.525" valve lift, and the 235 cam with 1.7 rockers would put valve lift at 0.507"/0.524". Too close for comfort on the exhaust valves.

Re: Help me build a 4.7L 300hp/300+lbft TorqueRRR

Posted: March 7th, 2018, 7:27 am
by darkartz
Well I already have purchased that spring, retainer, lock combo. So I'll have to live with it. Will have to trim the roller rocker options based on the camshaft.

Re: Help me build a 4.7L 300hp/300+lbft TorqueRRR

Posted: April 14th, 2018, 12:06 pm
by LRSimons
Something to consider on the roller rockers-

There was an episode of engine masters a few months ago comparing different styles of stock and upgraded rockers. The only power gain came with the 1.7 ratio rollers. Somewhere around 20 hp on a 500 hp motor with an extended powerband IIRC. The 1.6 rollers performed basically the same as stock rockers, with whatever reduced resistance offset by the increased weight.

Looks like 1.7 rollers may not be viable in your application- so 1.6 rollers are probably a waste of money compared to 1.6 stockers.



Certainly a cool item but IMO not worth the price tag unless you could adjust things to run the 1.7s.


Good luck on the build!

Re: Help me build a 4.7L 300hp/300+lbft TorqueRRR

Posted: May 7th, 2018, 2:08 am
by darkartz
LRSimons wrote: April 14th, 2018, 12:06 pm Something to consider on the roller rockers-

There was an episode of engine masters a few months ago comparing different styles of stock and upgraded rockers. The only power gain came with the 1.7 ratio rollers. Somewhere around 20 hp on a 500 hp motor with an extended powerband IIRC. The 1.6 rollers performed basically the same as stock rockers, with whatever reduced resistance offset by the increased weight.

Looks like 1.7 rollers may not be viable in your application- so 1.6 rollers are probably a waste of money compared to 1.6 stockers.



Certainly a cool item but IMO not worth the price tag unless you could adjust things to run the 1.7s.


Good luck on the build!
Thank you for getting back and your input. Sorry i have been off the internet for a while. Things have certainly taken a big turn since i initially started this thread. I have got in touch with Russ Pottenger and am getting a ported edelbrock head, SCR of 11.0:1, LS valve train, 68-235-4 114LSA camshaft, 1.7:1 yella terra rockers, SCAT forged rods, forged custom pistons, Manley valves etc. There's a substaintial increase in cost over the initial plan, but i figured that i had to make a few changes.

Re: Help me build a 4.7L 300hp/300+lbft TorqueRRR

Posted: May 18th, 2018, 1:23 pm
by darkartz
@Cheromaniac

I have finalized my parts with Russ Pottenger and currently have the below specs.
Could you kindly help me find the best available injectors for this setup?

4.7L stroker
3.895" 12wt crankshaft
3.935" (+0.060) bore
Custom Racetec pistons 1.385" height
Piston dish 15.0cc
SCAT 6.125" rods
Russ Pottenger ported Edelbrock 54cc head
Felpro 530SD 0.051" gasket
11.15 SCR
Quech 0.036"
Comp 68-235-4 camshaft
Yella Terra 1.7:1 rockers
2.00" intake and 1.55" exhaust valves
70mm 505 performance Throttle Body
2000 intake manifold

I have a 95 dual line fuel rail.
Planning to increase fuel pressure to 40psi (idle) 48psi (WOT) by using the Delphi FP10046 fixed FPR.

Russ has recommended the 27lb/hr Bosch injector,
From your 4.7L medium buck stroker, you have recommended the 30lb/hr Accel injector,

But the formula says;

hp x bsfc / #cyl x duty cycle
300x0.5/6x0.8 = 31.25lb/hr

So, considering that do I need a 32lb/hr or 34lb/hr injector? or a 30lb one or a 27lb one? And at what static pressure considering my new rail pressures.

Kindly advise,

Thanks,
Kasun

Re: Help me build a 4.7L 300hp/300+lbft TorqueRRR

Posted: July 30th, 2018, 10:31 am
by RustyTruck
Russ has recommended the 27lb/hr Bosch injector,
From your 4.7L medium buck stroker, you have recommended the 30lb/hr Accel injector,

But the formula says;

hp x bsfc / #cyl x duty cycle
300x0.5/6x0.8 = 31.25lb/hr

So, considering that do I need a 32lb/hr or 34lb/hr injector? or a 30lb one or a 27lb one? And at what static pressure considering my new rail pressures.
What injector did you decide on?

Re: Help me build a 4.7L 300hp/300+lbft TorqueRRR

Posted: July 31st, 2018, 3:00 am
by Cheromaniac
darkartz wrote: May 18th, 2018, 1:23 pm @Cheromaniac

I have a 95 dual line fuel rail.
Planning to increase fuel pressure to 40psi (idle) 48psi (WOT) by using the Delphi FP10046 fixed FPR.

Russ has recommended the 27lb/hr Bosch injector,
From your 4.7L medium buck stroker, you have recommended the 30lb/hr Accel injector,

But the formula says;

hp x bsfc / #cyl x duty cycle
300x0.5/6x0.8 = 31.25lb/hr

So, considering that do I need a 32lb/hr or 34lb/hr injector? or a 30lb one or a 27lb one? And at what static pressure considering my new rail pressures.

Kindly advise,

Thanks,
Kasun
Since you've opted for a 48psi WOT fuel pressure, you could go for the 27lb Bosch injectors that Russ recommends. The nearest I could find are the Bosch 0-280-150-361 which flow 26.9lb/hr @ 43.5psi (28.3lb/hr @ 48psi).

Re: Help me build a 4.7L 300hp/300+lbft TorqueRRR

Posted: July 31st, 2018, 8:32 am
by RustyTruck
hp x bsfc / #cyl x duty cycle
300x0.5/6x0.8 = 31.25lb/hr
Everywhere I look on the internet shows this formula for injector sizing. Based on that, a 300hp 6 cylinder would require a ~32 lb/hr injector. How are people successful using a 27 lb/hr injector then for a 300 hp stroker? Do our 300hp strokers never develop that power in reality (probably due to the large hp numbers being at high RPM) and thus we never need the correct injector size?

Re: Help me build a 4.7L 300hp/300+lbft TorqueRRR

Posted: July 31st, 2018, 4:01 pm
by SkylinesSuck
What is BSFC? But fuel pressure changes things. And injector sizing for something being tuned vs injectors that just get you close without a tune (like most Jeep stroker people) might not be the same. Trust me, listen to Russ.

Re: Help me build a 4.7L 300hp/300+lbft TorqueRRR

Posted: August 1st, 2018, 2:00 am
by Cheromaniac
RustyTruck wrote: July 31st, 2018, 8:32 am
hp x bsfc / #cyl x duty cycle
300x0.5/6x0.8 = 31.25lb/hr
Everywhere I look on the internet shows this formula for injector sizing. Based on that, a 300hp 6 cylinder would require a ~32 lb/hr injector. How are people successful using a 27 lb/hr injector then for a 300 hp stroker? Do our 300hp strokers never develop that power in reality (probably due to the large hp numbers being at high RPM) and thus we never need the correct injector size?
The formula assumes a BSFC (brake specific fuel consumption) of 0.5lb/hr per HP. Our strokers may be doing better than that due to improved cylinder head flow (ported head) and combustion efficiency.
Modern N/A engines are achieving figures as low as 0.4 so that formula needs to be modified to reflect this. Note that the BSFC changes with rpm and is usually lowest where the engine produces maximum torque.