Jeep Stroker 4,6 L Build up

[Tamraz]

Hi Tamraz,

i was not clear about your question, thats why i was asking if you mean the better acceleration and so on. Of course, the performance is the reason to build up a stroker. But anyhow, to know the real achievement, the car has to be dyno tested.

In daily driving i think i will notice 70 or 80 extra HP very easily anyway.

About the high flow waterpump. I can use a stock one, but Dino told me once that also to use a high flow pump is not a mistake at all ( especially here in summer ).

Here is what he wrote me:

The standard water pump will do fine but if you want a high-flow pump,
you can get one from http://www.flowkooler.com (that's what I have).

I will also think about to put an extra fan , but it is not yet clear if i need or not.

Cheers

yes... extra fan reduces the heat exchange time ( i.e faster cooling rate) so when added together with a higher flow rate pump the faster flowing water would be colder than as per the design aspect..... Chuck ! I am still worried though.... some specialist must calculate Delta T in and out the engine or else you could be super cooling (on the highway) and over heating (in down town traffic) with potential demage to the cylinder block or the upper block due to larger Delta between expansion/contraction beyond design tolerances....because the Regulator valve will be open most of the Time looking for colder water!

Conclusion: I would add the extra fan and keep the originally designed size of a pump. The result will be cooler water flow - yet with the OEM thermostat regulator valve still in place.. meaning that the regulator valve will open only when there is over heatiing, but if not the water goes back to secondary cycle and so on .... so instead of doing un-engineered changes based on 2 variables ( higher flow rate with less cooling power then add higher cooling fan with no proper inter -relationship, l would only do higher cooling rate by installing the extra fan... what do you think? why don't you consult with a real expert automotive engineer?

[Chuck]

Hi Tamraz,
it seems that you know what you are talking about. I´m really glad that you started this discussion, because a mistake can lead ( as you described ) to a fatal engine damage.

As you maybe know, i am a complete rookie with building up a tuned engine, so i have to follow successfull build ups which are "road" proven already.

Regarding the Stroker Build up and the thereby affected surrounding aggregates, i got all my infos from Dino, which is a professional and very experienced Jeep Guru.

I trust his advises in every field, especially because he has the same configuration in his Jeep as i´m to build up right now.

Btw, he lives in Al Ain, so the same weather conditions exist there in summer, such as in Abu Dhabi.

I heard the advice to put a high flow water pump not only from him, but also from some guys which have a stroker in there Jeeps in germany. OK, they have different weather conditions, so it might be usefull to re-think this part of the build up.

Do you have any specific calculations regarding the use of different water pumps and thermostates / fans ?

What you wrote about the "super cooling", i´m not sure if it will hapen at all. I mean in UAE you will have minimum temperatures like now of lets say 20 degree Celsius. The engine should run in optimum with about 80 to 90 degree, max 100 Degree Celsius. If it is really "cold" like now, i believe that even with a extra fan ( that runs on temperature switch ) the engine will not cool down dramaticly dangerous, you agree ?

So, the focus should be on the overheating only.

Under hot conditions, lets say driving in hot summer for hours in the desert over dunes, the extra fan will get more cool air to the engine. The thermostat it self but opens only when in the primary circle the water gets too much hot ( above 120 Degree ) you agree as well ?

For what purpose you think the high flow water pump is made for ? In my opinion the higher flow will keep the peaks of overheating avoided. See it like this, the point which you not can change is the radiator. This is not a variable item at all ( only with a change of the radiatorsize ).

So, there is flowing water by in the radiator and if more water is flowing by more water will be cooled ( but as you stated already, not to this low Delta T a normal pump will do ) but more even. You agree with me ?

Cheers

[Tamraz]

Chuck..

I am a rookie too... its just basic flow dynamics (heat transfer rate)..: energy = delta T per time /area

and in fluid dynamics terms : force (flow rate energy) = pressure of flow from point a to b per unit time/ area

since the area is constant (same old hose tubes ) & Same original Radiator (the heat transfer median)./. so you will end up just increasing the flow rate of coolant without being cold enough... while the objective is to change 2 variables to reach for the same cooling rate the engine was designed for..

So I would vote for " a must add additional front fan" just to insure it will cool the Radiator water faster since The coolant flow inside the Radiator is faster after adding the larger Flow pump... this way you really improve cooling efficiency.

Unfortunately the last time I used equations and formulae was 27 years ago on my graduation exams.. and ever since I just use what is left over in the memory !

and By the way sudden cooling happens in abudhabi too. If the thermostat regulator is out of order or you bypass it ( like most of egyptian mechanics do to older cars in summer time ) and you decided to drive on E11 towrads Dubai at 140km/hr then reach Dubai heavy Traffic for lets say 4 hours..you will surely loose the upper Cylinder block why? because:

on the highway drive the wind impact force ( acts as additional cooling power like putting the fan towrads your face in hot summer Day) on Radiator face beacuse of high speed causes sudden cooling of the coolant behind. such coolant flow fast and passing the regulator valve directly to the engine block .. the engine will enjoy that and coolant Temprature would be in the range of 65-75 Degrees. Once You reach defence R/A and you are stuck in traffic... no more wind impact as its is Gone, and all suurounding engines heat plus the troubled regulator will allow hot coolant to the engine,,, the engine will get hotter till you reach the evaporation phase of coolant ( the moment you see steam vapor coming from underneath the grill and bonnet..
Conclusion:

additional fan is mandatory
careful eye on regulator valve thermostat
Careful eye on the oil coolling cycle too.. simple cooling fins on the oil resvoir cover ( like motor cycle cylinders) will help you so much improving the over all engine performance

[Bulldozer]

I agree with Tamraz, unless u enlarge the radiator if possible, keep the thermostat it helps in safe the engine ad improve the performance and keep the engine temp almost constant

[Chuck]

Thanks Guys for this good explanations of your views.

Actually i have no idea how the "New" engine with the Stroker will behave in summer time compare to the stock one.
I believe so far, that it will get not that much more hotter than a stock engine at all.
It is still a stock engine only with bigger stroke, isnt it ?

I will try to connect to Dino to give us his opinion on this discussion, but i believe that your worries are not that baseless at all, thanks again that you raise this questions and doubts.

At the end, i post the build up of the engine not for myself, but also for all the guys in the club which are interested to do the same "adjustments".

Therefore i want to be completly sure that what i post and describe here is usefull ( and correct ) for the community, especially because of the special weather conditions we have to face here in summer.

Btw, i thought about to place some "Airgrills" in the bonnet already last summer, because the heat the engine developed was already quite a lot, and this with the stock engine only ( as some of you surely experienced on your own Jeeps).

[Kris]

get a 3 core aluminium radiator with an auxilary electrical fan ( the cherokee has it anyway?) , change your thermostat to a 160 Fahrenheit one and make sure your thermostat housing is in good condition and lets the pressure build up properly.
whatever u do , DONT run the engine without a thermostat.
you'll warp your cylinder heads.
ive been thinking abt the flowkooler pump too , but its kinda like what Mr.Tamraz said..the thermostat opens and the coolant is pumped through too quickly to really let it absorb the heat from the cylinder block...doing more harm than good...not enough heat transfer..
hood vents help get the heat from under the hood away , but some ppl say it helps keep the temp down , others say it does nothing to get the temperature of the block down...
only thing i found helps is the 3 core radiator , 160 fahrenheit thermostat.

[DinoStroker]

After many years of running a Flowkooler high-flow water pump and a 180* t'stat in my Jeep (first my old 4.0, then the stroker), I can honestly say that I'd never go back to using the stock water pump nor the stock 195* t'stat.
A 180* t'stat will allow the engine to stay cool enough in the summer while not overcooling in the winter. A 160* t'stat is a definite no no. The engine could run too cool with a 160* unit and the engine computer stay in rich warm-up mode, risking fuel wash of the cylinder walls and accelerated wear.
I've found that a high-flow water pump keeps the engine cooler for longer when climbing long steep hills (like Jebel Hafeet) and it's definitely better than the stock pump if you do a lot of dune bashing or any other activity that loads up the engine.
As far as radiators go, the stock factory radiator is good enough as long as you've maintained it properly and changed the coolant every two years to prevent it from getting blocked up with rust and scale. My original radiator lasted more than 13 years.
The factory mechanical clutch fan is, as far as I'm concerned, a 5lb piece of junk so I recommend getting rid of it and replacing it with a 14" diameter electric fan. You already have one electric fan in the Cherokee and you can run a second one from a separate relay. Wire the second fan up so that it switches on and off together with the factory fan. I've been running this set-up for almost 7 years in my Jeep and I've been very happy with it. Here's my write-up:

http://www.angelfire.com/my/fan/electric.html

Regarding hood vents, out here they're definitely a good idea. Their main benefit is to allow hot underhood air to escape when the radiator cooling fans are switched on, and this helps the engine cool down faster.
Cylinder heads and blocks can crack if there's either overheating or a sudden change in engine temperature, but that isn't going to be an issue as long as your cooling system is up to scratch and the engine temp. stays within the 180-220*F (85-105*C) range.

[Chuck]

Hi, after a few days of calm i got some news for you.

All works in the turning shop are done now and the engine parts are ready to be assembled.

Unfortunatly the guys of 7 Performance Alyasy prepare now their 2000 HP !! cars for a Dune race on 2nd of Feb. in the near of Liwa. This engines are really monsters. They are equipped with NOS as well. 8O

Check this out




That means, that they do not have time to work on my stroker until the end of next week.

But anyhow, i believe if they can work on such engines, they will take also good care of my little stroker 8)

In the meantime i will get all the missing parts together. I bought already the upper and lower gasket sets for about 450 AED.



Btw, i meet "Bulldozer" at 7 Performance by accident that day, it was nice to meet you man.

Cheers

[MegaMoe]

hey man good job! and yeah they're preparing for Moreeb fun

[Bulldozer]

It was nice meeting u man those guys r my friends i told the guys about them, waiting to c ya on the sand very sooooon

[Chuck]

Hi all,

i found something quite interesting on wikipedia about the 4,2 and 4,0 L engines.

Check this out http://en.wikipedia.org/wiki/AMC_Straight-6_engine

As described earlier, the easy interchange of the AMC enginesparts makes the stroker build up possible.

Read the articles for the 258 and the 4,0 L engines, which explaines quite a lot already.

Quote:

The better flowing 4.0 L heads can easily be modified to fit earlier engines right along with the fuel injection system. The longer stroke 258 crankshaft and rods will drop right in the slightly larger bore 4.0 L block, easily creating an even higher torque 4.5 L engine with the stock bore (4.6 L bored 0.030″ over, and 4.7 L with a 0.060″ overbore). Blocks should be sonic checked for adequate cylinder wall thickness before boring 0.060″ over.

[iguana]

Nice one Chuck. You know I couldn't find the crankshaft anywhere in the net till now

[Chuck]

Nice one Chuck. You know I couldn't find the crankshaft anywhere in the net till now

I will ask my guys in germany, if they know any dealer which offers new 258 crankshafts and rods. But i guess at least Jeep should be able to deliver.

[iguana]

I will give Jeep a call on Sunday to check

[iguana]

Chuck, is this what we are looking for?

http://www.rockauto.com/dbphp/mak,JEEP, ... 6+1BBL+(A)