Jeep Strokers

So I'm trying to figure out ball park hp for my build so I can order the right injectors
4.2 crank ,4.0 block, 4.0 rods ,cylinder head 0630 not sure if.there was a big difference in intake manifold but I have both
Cleggs master engine rebuild with their stage one cam
Pistons silvolite 2229.030
+11
Compression height of 1.581 in
Judging by the compression calculator I'll have scr of 10.13:1 and a dynamic of 8.32:1 with a dcr of 7.71:1 at my elevation
Can anyone point me in the right direction I can try to figure out the math but don't know where to start


4.59L
279.89 cu

I can see a problem right away.
You can't use 4.0L rods with Silvolite 2229 pistons on a 4.2L stroker crank 'cause the piston crowns will be 0.20" above the block deck at TDC.
You'll either need to use Silvolite 2229 pistons with 4.2L rods (not a good idea 'cause you'll have too high compression and poor quench) or use 4.0L rods with custom pistons (much better idea). Russ Pottenger has the perfect solution for that.

Cheromaniac wrote: ↑June 16th, 2023, 10:22 pm I can see a problem right away.
You can't use 4.0L rods with Silvolite 2229 pistons on a 4.2L stroker crank 'cause the piston crowns will be 0.20" above the block deck at TDC.
You'll either need to use Silvolite 2229 pistons with 4.2L rods (not a good idea 'cause you'll have too high compression and poor quench) or use 4.0L rods with custom pistons (much better idea). Russ Pottenger has the perfect solution for that.

Just great I wonder why cleggs would send me those pistons then I told them I was stroking the jeep gave them all the info the asked for . Already had the blocked bored and honed for these pistons hell already have them installed just waiting on cam to continue

Tonyt22 wrote: ↑June 16th, 2023, 9:17 pm So I'm trying to figure out ball park hp for my build so I can order the right injectors

Rather than guessing an engine's power potential to size a fuel system, traditionally, the engine is built to a specific power goal along with it's ancillary systems.

What kind of wheel HP are you trying to make?

Randy Bobandi wrote: ↑June 17th, 2023, 5:59 pm

Tonyt22 wrote: ↑June 16th, 2023, 9:17 pm So I'm trying to figure out ball park hp for my build so I can order the right injectors

Rather than guessing an engine's power potential to size a fuel system, traditionally, the engine is built to a specific power goal along with it's ancillary systems.

What kind of wheel HP are you trying to make?

That's the problem have judging by recipes I've read I should be anywhere from 250 -300 but looks like im going to need to change my pistons so hopefully I can switch to something tested

Tonyt22 wrote: ↑June 17th, 2023, 7:40 pm That's the problem have judging by recipes I've read I should be anywhere from 250 -300 but looks like im going to need to change my pistons so hopefully I can switch to something tested

If your head is unported, I'd say you're more likely to end up somewhere around 240hp. Since you have a 93 XJ, a set of Ford 24lb injectors like the ones I used in my stroker will be fine. The stock fuel pump is also up to the job.

Tonyt22 wrote: ↑June 17th, 2023, 7:40 pm I've read I should be anywhere from 250 -300

Wheel horsepower or crankshaft horsepower?

Randy Bobandi wrote: ↑June 19th, 2023, 7:25 am

Tonyt22 wrote: ↑June 17th, 2023, 7:40 pm I've read I should be anywhere from 250 -300

Wheel horsepower or crankshaft horsepower?

My estimate is 240 crank HP.
There are many variables (e.g. type of dyno, weather correction factor, tire size, axle gear ratio, type of transmission, if there's a transfer case, type of torque converter, transmission ratio used, and whether the vehicle is FWD, RWD, 4WD) that can affect wheel HP, so it's difficult to estimate that without knowing all those details.

So got off the phone with cleggs looks to be a miscommunication
They suggested KB424C to replace the 2229 pistons any issues beyond lower compression with these ? I'm also running cleggs stage 1 cam

Cheromaniac wrote: ↑June 19th, 2023, 8:51 am

Randy Bobandi wrote: ↑June 19th, 2023, 7:25 am

Tonyt22 wrote: ↑June 17th, 2023, 7:40 pm I've read I should be anywhere from 250 -300

Wheel horsepower or crankshaft horsepower?

My estimate is 240 crank HP.
There are many variables (e.g. type of dyno, weather correction factor, tire size, axle gear ratio, type of transmission, if there's a transfer case, type of torque converter, transmission ratio used, and whether the vehicle is FWD, RWD, 4WD) that can affect wheel HP, so it's difficult to estimate that without knowing all those details.

So got off the phone with cleggs looks to be a miscommunication
They suggested KB424C to replace the 2229 pistons any issues beyond lower compression with these ? I'm also running cleggs stage 1 cam
Edit called cleggs back and switch over to their (KB438C) D shape combustion with 21cc

Tonyt22 wrote: ↑June 19th, 2023, 9:54 am Edit called cleggs back and switch over to their (KB438C) D shape combustion with 21cc

Yeah that's more like it:

https://www.cleggengine.com/jeep-4-0-st ... b438c.html

The quench would still be more than is ideal at 0.070" but you could still run 89 or 91 octane gas without issue.

Cheromaniac wrote: ↑June 19th, 2023, 10:14 am

Tonyt22 wrote: ↑June 19th, 2023, 9:54 am Edit called cleggs back and switch over to their (KB438C) D shape combustion with 21cc

The quench would still be more than is ideal at 0.070" but you could still run 89 or 91 octane gas without issue.

Which head gasket would you recommend not sure how much they will affect compression

Stock replacement 53010587AA / Victor Reinz 54249: Compressed thickness 0.043", bore diameter 4.000", compressed volume 8.85cc

Edelbrock EDL-7348: Compressed thickness 0.042", bore diameter 4.005", compressed volume 8.67cc

Cheromaniac wrote: ↑June 19th, 2023, 10:39 pm Stock replacement 53010587AA / Victor Reinz 54249: Compressed thickness 0.043", bore diameter 4.000", compressed volume 8.85cc

Edelbrock EDL-7348: Compressed thickness 0.042", bore diameter 4.005", compressed volume 8.67cc

So based on the calculator with the victor reinz
I'll have a SCR 9.3:1 ,DCR 7.65:1 ,adjusted elevation DCR 7.05:1, quench 0.0645 that with the KB438C -21cc and clegg stage 1 cam according to the slip intake closing angle of 61.5

At your elevation, the thinner air should allow you to run 87 octane.