Let's build a 4.6 stroker

[Hussler]

Need to redo the engine in the jeep and I need some more torque in the 2,000-3,000 range for towing my boat. From my guesstimation 200hp and 275tq crank would be fine. The cost isn't a huge factor, reliability and simplicity is most important. I'm looking at this bottom end kit (prob the forged rods for lols)

http://www.cleggengine.com/stage-ii-4-6 ... -1c-r.html

And this cam kit

http://www.cleggengine.com/jeep-4-0l-st ... t-kit.html

I'd like to keep the stock comp ratio so I can run cheap 87, I daily drive it.

Not sure on the top end, I need a new cam (stock cam got chewed up my own fault) and the head should at least be refreshened. What could I expect out of it with a mild cam and no head,intake, exhaust work?

I'd like to keep it simple, I don't want to get into any tuning (it's pre ObdII) I already have the Ford injectors and I understand I will need the Hesco adjustable fuel pressure regulator.

Would I need more tuning (adjustable map ect) to run a Clegg ported head and their stage 2 cam?

My biggest concern is if any tuning is required, I don't have a dyno or any performance shops near me and I don't want to be chasing detonation,vibration, check engine lights. I've built up motors before but they were carbed and not daily drivers. This will be my first stroker.

Hope to have a decision in the next week and parts together by the end of the month

[Cheromaniac]

What do you think about this recipe?

4.6L Low-buck, low CR "rockcrawler"

Jeep 4.2L 3.895" stroke crank
Jeep 4.0L 6.125" rods
Custom forged +0.030" bore pistons, compression height 1.380", dish volume 32cc (Russ Pottenger can supply)
8.8:1 CR
CompCams 68-115-4 192/200 degree camshaft (works with stock valve springs)
DIY ported HO 1.91"/1.50" 57cc cylinder head
Mopar/Victor 0.043" head gasket
0.043" quench height
Ford 24lb/hr injectors for '87-'95 engines
242hp @ 4600rpm, 317lbft @ 3000rpm

Clegg's kit is good but a set of custom pistons would be a better option than those IC668's as they'd be tall enough to be level with the block deck at TDC and save you the cost of milling the block to reduce the deck clearance (IC668 pistons are ~0.027" below the deck at TDC).

[Cheromaniac]

What do you think about this recipe?

4.6L Low-buck, low CR "rockcrawler"

Jeep 4.2L 3.895" stroke crank
Jeep 4.0L 6.125" rods
Custom forged +0.030" bore pistons, compression height 1.380", dish volume 32cc (Russ Pottenger can supply)
8.8:1 CR
CompCams 68-115-4 192/200 degree camshaft (works with stock valve springs)
DIY ported HO 1.91"/1.50" 57cc cylinder head
Mopar/Victor 0.043" head gasket
0.043" quench height
Ford 24lb/hr injectors for '87-'95 engines
242hp @ 4600rpm, 317lbft @ 3000rpm

Clegg's kit is good but a set of custom pistons would be a better option than those IC668's as they'd be tall enough to be level with the block deck at TDC and save you the cost of milling the block to reduce the deck clearance (IC668 pistons are ~0.027" below the deck at TDC).

[Russ Pottenger]

Hussler,
I'd like the opportunity to give you a quote on one of
my custom Stroker kits based on your needs and criteria
and try to answer any questions you might have.

Thanks,
Russ Pottenger
Bishop-Buehl Racing Engines
531 N. Lyall Avenue
West Covina, Califirnia 91790
Work (626) 967-1000
Fax (626) 967-7836
Cell (626) 673-2203
Email/PayPal: [email protected]

[Hussler]

What do you think about this recipe?

4.6L Low-buck, low CR "rockcrawler"

Is that a dynod build or estimate hp/tq? What would it look like without the ported head?

[Hussler]

Thanks,
Russ Pottenger m

Email sent

[Cheromaniac]

Is that a dynod build or estimate hp/tq? What would it look like without the ported head?

Not actual dyno umbers but simulated on a Desktop dyno with detailed specs to ensure a high degree of accuracy.
With a stock rather than a ported head, the outputs will be about 220hp/310lbft.

[Hussler]

Is that a dynod build or estimate hp/tq? What would it look like without the ported head?

Not actual dyno umbers but simulated on a Desktop dyno with detailed specs to ensure a high degree of accuracy.
With a stock rather than a ported head, the outputs will be about 220hp/310lbft.

You really think a mild cam and 8.8 comp 4.6 could pull off 300tq? That's all I really want

[Russ Pottenger]

Jim,
Check out the email that I sent you.
Hopefully that will answer some of your questions.

Feel free to give me a call,

Russ

[Cheromaniac]

You really think a mild cam and 8.8 comp 4.6 could pull off 300tq?

Yup. With the right cam to promote good cylinder filling at low/medium rpm, there's no reason why not.

[Hussler]

Chatting back and forth with Russ.

I'm finding a lot of mixed info on tuning, it seems these older computers are able to compensate for the strokers on their own? Is this true? IF I went with a radical cam and a ported head/edlebrock aluminum head would I have to mess with the MAP and or dyno tune? Staying 87 octane regardless

[jsawduste]

Chatting back and forth with Russ.

I'm finding a lot of mixed info on tuning, it seems these older computers are able to compensate for the strokers on their own? Is this true? IF I went with a radical cam and a ported head/edlebrock aluminum head would I have to mess with the MAP and or dyno tune? Staying 87 octane regardless

Russ is a great guy to deal with. I feel privileged to yak with him several times a month. Guys knows his stuff.

My 2 cents on this camshaft/compression/octane based on practice with stock and modified ECM's.
It's tough to make and tune a stroker to run on 87 octane. Reason being that the combustion chamber design is not all that efficient. It's a real balancing act to get static and dynamic compression ratios combined with spark lead to work well with 87. You leave a lot on the table setting up these engines to run on 87. At the very least having a tight quench is paramount.

My favorite cam runs in the 220's duration with a static compression of 10.7 on 91 octane with no problem. Has plenty of low end and enough cam to pull hard in the upper ranges. I feed it 93 because the timing has been bumped 5 degrees also. The fore mentioned quench is tight and on my personal engine it does it on an OBD1 ECM with no MAP adjustment.

My customers are running OBD2 and many of them with stock ECM calibration. Just not on 87 octane.

Several of better know tuners cringe at trying to cal an 87 engine. It can be done but when you start adding cam it becomes pretty difficult.

[Hussler]

What exactly makes it tough to tune on 87? Detonation, power, ect?

[jsawduste]

The fine balancing act between dynamic and static compression and detonation. The more octane the more forgiving.

Not sure if you are familiar with how a camshaft effects compression. IE dynamic and static. If not then perhaps a little Googling might be useful for you.

A rough example that you may have seen before.

Looking at your favorite cam companies catalog and you notice a footnote that says "best for engines over X amount of compression". That`s because the cam "bleeds off" x amount of compression "dynamic" . Thus the static has to be high enough to allow for the amount of bleed off.

Think about that and apply the physics to your stroker build.

[Hussler]

I would assume though that the Pistons and cam combo russ suggested to me for an 87octane motor must be a fairly home run setup? Is there anything else I can do besides ensure the quench and timing is correct?