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4.8 stroker build

Posted: October 27th, 2016, 5:41 pm
by GreenYJ
I'm building a stoker for my '94 YJ. I've owned it since '96 and put 180,000 of it's 182,000 miles on it. The original 4.0 has gotten pretty weak. So on to the stroker build!
I've been gathering parts for at least 12 years, probably longer...ha ha!

12 cw 258 crankshaft. Turned .010 .010
Eagle h-beam rods 6.150" long (had these a while)
Camcraft custom camshaft
Yella terra non-adjustable 1.7 rockers
ARP main studs
ARP head studs
Ferrea LS1 valves
Edelbrock 4.0 bare aluminum head
4.000" SRP dished pistons (yes, I'm going .125" over)
Cometic 4.060" bore .051 mls head gasket
Both early & late efi intakes

On a side note, I have access to a dyno and would like to test the 2 intakes to see what the actual difference is, if any. I would think obd1 from the boneyard would be the easiest way to do that. I could also test stock shorty against long tube pacesetter too.

That's all I can think of at the moment. I'll get some pictures and post them later.

Roger

Re: 4.8 stroker build

Posted: October 27th, 2016, 8:13 pm
by GreenYJ
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Re: 4.8 stroker build

Posted: October 27th, 2016, 8:17 pm
by GreenYJ
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Re: 4.8 stroker build

Posted: October 27th, 2016, 8:25 pm
by GreenYJ
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Re: 4.8 stroker build

Posted: October 31st, 2016, 3:06 pm
by Russ Pottenger
What are you shooting for a static compression ratio?
It looks like it's gonna be pretty low.

Re: 4.8 stroker build

Posted: October 31st, 2016, 7:11 pm
by GreenYJ
I'm figuring around 9.8:1. It's my DD so I'm hoping to run on regular gas. I think the aluminum head will help towards that. The piston is for a sbchevy and has a 31cc dish with a 1.425" compression height. I plan to cut around .050 off of the top to fit my application. That should drop the dish to around 25cc.

Re: 4.8 stroker build

Posted: November 14th, 2016, 7:01 pm
by GreenYJ
And the rest of the parts arrived. I guess it's time to get cracking!

Re: 4.8 stroker build

Posted: November 14th, 2016, 7:13 pm
by GreenYJ
I bought one of these so I can still run it on the dyno even if I don't find an obd1 engine harness.

Re: 4.8 stroker build

Posted: November 30th, 2016, 7:51 pm
by GreenYJ
And one nasty '93 block. It ended up sonic testing thicker than the '97 & '98 blocks I have.

Re: 4.8 stroker build

Posted: December 3rd, 2016, 9:57 am
by Russ Pottenger
Can you post up your sonic test sheet with the numbers that you came up with?

Re: 4.8 stroker build

Posted: December 3rd, 2016, 7:56 pm
by GreenYJ
Sure. They're at work so it'll be Monday night.

Re: 4.8 stroker build

Posted: December 5th, 2016, 8:24 pm
by GreenYJ
The '97 & '98 are short blocks that I ran #1(and #6) to BDC to do quick check to determine if either was worth disassembling for my purposes. All 3 blocks seem to taper to a thinner area 2/3rds of the way down.
1998 std bore
#1 .200 .220
#6 .183 .230
1997 Jasper .030 over
#1 .205 .205
#6 .205 .230
I actually checked the '93 block first and since the '97 & '98 blocks came up thinner, I didn't bother with the rest of the cylinders.
1993 std bore
#1 .220 .230
#2 .210 .235
#3 .220 .230
#4 .230 .220
#5 .210 .240
#6 .210 .240
I couldn't figure out how to draw circles to write around.

Re: 4.8 stroker build

Posted: December 6th, 2016, 10:36 am
by Russ Pottenger
Your numbers coincide with what I typically come up with.

Thanks for sharing!

Russ

Re: 4.8 stroker build

Posted: March 16th, 2017, 4:12 pm
by GreenYJ
I acquired an LM-1 this week along with a remote display gauge. Apparently it has analog outputs that can be programmed to mimic narrow band O2 sensor. I'm hoping to make this work in my YJ with the new stroker.
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Re: 4.8 stroker build

Posted: June 21st, 2018, 6:49 pm
by GreenYJ
Been a while since I posted any updates. Everything had been on hold, family stuff, health issues, life in general...
Block has been bored .120" over to 3.995". Still need to hone to size. Pistons and rods have been pin fitted. Turns out Eagle rods have a Ford pin diameter (.912") and my pistons have sbc pins (.927"). Big end of the rods are on the high end of the specs.
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