Inline stroker newbie

[Brandon_k02]

I hope i dont sound like a broken record asking this but i am building a stroker and i need help choosing a connecting rod. Now 1st... Is the 4.0 rod too long when paired with a 4.2 crankshaft? And if not is the rod bearing dia. On the crank the same between the 4.0 and 4.2?

[Russ Pottenger]

The short answer is both rods can be used to turn your 4.0 into 4.6 or 4.7 (.030 .060 overbore) utilizing a Jeep 258
crankshaft. They will use different pistons.

Dino Savva has put together a very informative and comprehensive webpage that will answer
most of the initial common questions asked.

Welcome aboard!



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

[Brandon_k02]

So using the 4.0 rod with the 4.2 crank, how much lift can you use before the valves hit the piston?

[Brandon_k02]

As I dig more into building this stroker , I realize that by using the 4.0 rod , I am limited on what kind of piston I can buy. Since the pin height has to be lower with the 258 crank/4.0 rod combo. What's the cheapest piston out there to buy? So far I'm leaning towards 505 performance because they include rings. Now if I went with the 4.2 rod instead, how bad are the detonation issues? And what's the common remedy for it

[Russ Pottenger]

One of the cost considerations is whether you have (getting harder to find) a set of 4.2/258 rods.

By the time you have to source a set of 4.2 rods make the desirable mod to a set of cast 677 pistons,
Your close to the cost of the forged 944 pistons.

To answer your detonation concerns. A compression ratio of something around 9:1 with a tight quench
will help allot. As long as you have enough fuel and don't dump a bunch of timing in it, your good
to go.

[SilverXJ]

Check out Bulltear pistons. I wouldn't give 505 a dime for their horrible customer support.

[IH 392]

The only way your going to get the valves into the pistons is if the timing chain breaks.

[Frankenstien]

Here use these rods and these pistons and these rings. $400 +/- done. I personally just went this route myself.
Yes the rods are 707 copies I had two sets of 707 to compare and weigh.


http://www.jeep4x4center.com/connecting ... 37812.html $180


http://www.summitracing.com/parts/slp-h802cp60 $100


http://www.summitracing.com/parts/slp-e-925k60 $80

[bigal389]

I have a couple sets of the 4.2 rods I would part with if you want to pm me.

[Russ Pottenger]

I have a couple sets of the 4.2 rods I would part with if you want to pm me.

PM Sent

[bigal389]

Replied!

[Brandon_k02]

Thanks for all the info guys! Now next question... What heads will fit my 4.0? Its a late 1990 block and wheres the best and cheapest place to get oversized valves?

[Cheromaniac]

Thanks for all the info guys! Now next question... What heads will fit my 4.0?

Any 4.0L head from '87-'06 will fit but the most desirable are the '91-'95 #7120 and the '96-'99 #0630 castings. The only difference between them is that the earlier heads have a port at the back for the coolant temp. gauge sending unit.

[Russ Pottenger]

Thanks for all the info guys! Now next question... What heads will fit my 4.0? Its a late 1990 block and wheres the best and cheapest place to get oversized valves?

My advise to you is find someone reputable that builds performance Jeep engines and have them
build you a head to your application and budget.

For example most of us are using Chevrolet LS valves. To fully utilize the benefits of larger valves, some experience in cylinder head porting is necessary.

If you don't happen to have anyone local to you I'd be happy to help
with parts and service in anyway I can.

Russ
Bishop-Buehl Racing Engines
531 N. Lyall Avenue
West Covina, California 91790
Work (626) 967-1000
Fax (626) 697-7836
Cell (626) 673-2203
Email: [email protected]

[Brandon_k02]

From the math I did, the stock valve sizes are just fine for the size piston I'm using. Now I plan on choosing the comp cam which is 262/270 duration 44. Deg overlap and 111 LSA... What should I expect out of this cam? It's not too far off the specs from Dino's stroker build. I'd like to be able to gain some mpg with this build, the 12 mpg I'm getting on my stock 4.0 is terrible on the wallet haha what kind of scr/Dcr can I expect going that route