Junkyard stroker

[Compfreak530]

Hey yall, gonna be newbish and ask, and hope that someone can help me. i currently just bought a 88 XJ with no engine that i want to drop a stroked engine into. i am currently a certified mechanic so tools and ability are no problem. but when it comes to <mods> and <fabricating> im useless.. i have spent the last few weeks searching the deep interwebs and so far have come up short.. i am on a very very limited budget so here it goes... i am starting from scratch, no engine in vehicle.. gonna head to junkyard and get a 4.0 out of a 93 for the better air flow. i have the sensor and fuel issue figured but my main problem is the internals. iv read that its as simple as dropping a 4.2 crank and a 4.2 rods in the 4.0 block and that covers it. other places iv read that you need alot more then that.. so i basically want a super budget build.. stock crank from a 75 gremlin < i belive its 12w> connecting rods to go with it.. and a mild cam to help with mid range power.. i will completely tear the block apart get the head machined and the block cleaned.. but what im not sure of is all the small details..someone said if i use stock 4.0 pistons there too shallow while others say they work fine. for someone on a <cheepscape> budget what can i do? and piston dishing. is it required for valve clearance? or for combustion efficiency?

TLDR.. got the idea for 4.2 crank and rods.. whats the absolute cheapest piston that can be installed without special milling? do i need to dish the pistons? thanks

[DaemonForce]

A problem? The internals are a creative chaos that makes the stroker project an easy but unpredictable build. The dealer isn't going to be much help, the junkyard is the most ample provider and the parts shops fill the gaps. As long as you're somewhat skilled with disassembling then you're already halfway done and should be able to get through this without much effort.

Keep it simple. Figure out what parts work and keep around what doesn't work as a reference until it can be replaced. You'll need a detailed bill of materials for both engines. The Overhaul Guide is great for checking your work. If we were focused on building a stroker for the Gremlin then you would be focused on far more details but since the target vehicle is an ordinary XJ it's a safe bet that you won't have to fabricate anything. The remaining electrical should be perfectly fine.

As for small details, both of these engines are full of them and it's hard to pay attention without a list. Just use common sense. Keep the parts clean and orderly. You'll have to figure out the important details as you go(clearances, appearances and specific sequences). Commit to a linear build priority. It's crucial you work on one section at a time if you want this to be a strong and stable performer. To me this means: The head, the block, the bottom, the fuel delivery system and then electrical. As in I build in that exact order.

I can't be of much help with the pistons since I haven't gotten that far yet. I had to bore my block 0.060" over so next on my list is a nice cheap set of Speed Pro hyper pistons. They run just under $100 on Summit Racing at the moment and even though I never have enough capital to afford these components I really don't have room to complain. I'll be using a mild Crower cam and the stock valvetrain so I'm not worried about internal clearances. When you overhaul the head you might want to pay attention to the condition of your valves. I notice the exhaust valves often take quite a beating and all the grinding in the world doesn't seem to help anymore.

[Cheromaniac]

Hey yall, gonna be newbish and ask, and hope that someone can help me. i currently just bought a 88 XJ with no engine that i want to drop a stroked engine into. i am currently a certified mechanic so tools and ability are no problem. but when it comes to <mods> and <fabricating> im useless.. i have spent the last few weeks searching the deep interwebs and so far have come up short.. i am on a very very limited budget so here it goes... i am starting from scratch, no engine in vehicle.. gonna head to junkyard and get a 4.0 out of a 93 for the better air flow. i have the sensor and fuel issue figured but my main problem is the internals. iv read that its as simple as dropping a 4.2 crank and a 4.2 rods in the 4.0 block and that covers it. other places iv read that you need alot more then that.. so i basically want a super budget build.. stock crank from a 75 gremlin < i belive its 12w> connecting rods to go with it.. and a mild cam to help with mid range power.. i will completely tear the block apart get the head machined and the block cleaned.. but what im not sure of is all the small details..someone said if i use stock 4.0 pistons there too shallow while others say they work fine. for someone on a <cheepscape> budget what can i do? and piston dishing. is it required for valve clearance? or for combustion efficiency?

TLDR.. got the idea for 4.2 crank and rods.. whats the absolute cheapest piston that can be installed without special milling? do i need to dish the pistons? thanks

I can suggest two options (click on stroker recipes link in my sig.):

1. Traditional 4.6L poor man's stroker using 258 crank, 258 rods, 677CP pistons, stock cam (or Melling stock replacement), new lifters.
2. Modified poor man's stroker using 258 crank, 4.0L rods, Keith Black IC944 pistons, stock cam (or Melling stock replacement), new lifters.

The first option is as cheap as a stroker gets.
The second is a little more expensive (IC 944 pistons cost slightly more than the combined cost of 258 rods/677CP pistons), and the squared small ends of the 4.0L rods need to be rounded off to allow a full rocking motion of the IC944 pistons.

[Compfreak530]

Thanks for the quick replies. so.. if i do the poor mans stroker and get the pistons that you mentioned,677CP. would i need to have them dished or does that come after installed to measure the quench? i would like to make only one trip to the machinist. also if i use those parts. can i just use a regular head gasket kit? or will the machinist be able to tell me which one i should get depending on quality of the head and block? when you say you >had to have it bored over .060< is that because of the wear on the engine or just because you wanted bigger pistons? thnaks

[Cheromaniac]

You won't need to have those pistons dished and you won't need to have the block decked either, but shaving 0.020" from the block would be a good idea to reduce the quench and raise the compression ratio. You can use the Victor Reinz 0.043" multi-layer steel head gasket.
I had the cylinders bored +0.020" in my engine so that they'd be round and true (no taper) for good ring sealing. Always a good idea when you're using an old block.

[SilverXJ]

The cheapest route would be to keep the stock cam if good and use a new set of lifters. Aftermarket performance cams may need valve spring work. Use new pistons at minimum over bore. Of course new rings, bearings, timing set, oil pump, etc.

[Compfreak530]

one last question. im trying to find the Sealed Power 677P pistons but summit says unavailable.. summit recommends the FEM-677P as alternatives.. is this a good option? or should i go with something else? perferably something cheaper

[DaemonForce]

Funny that FEM-677P is unavailable and pointing to 677AP. Those are stock bore pistons so if that's what you're going for then I say get it. Those look like they'll work fine.

[Cheromaniac]

Funny that FEM-677P is unavailable and pointing to 677AP. Those are stock bore pistons so if that's what you're going for then I say get it. Those look like they'll work fine.

There's a choice of 677AP20, 677AP30, and 677AP60 as oversized pistons.
Please DON'T get the stock bore pistons.

[Compfreak530]

Ok so your recommending that I get the 20 over bore and bore out the block .020 just to be safe.. By using those pistons do I need to deck the block for proper quench? Thanks

[Knoxes]

It seems like doing the bore first would be a good idea - that way you know what you're dealing with.

[Cheromaniac]

Ok so your recommending that I get the 20 over bore and bore out the block .020 just to be safe.. By using those pistons do I need to deck the block for proper quench? Thanks

Like I said earlier:

You won't need to have those pistons dished and you won't need to have the block decked either, but shaving 0.020" from the block would be a good idea to reduce the quench and raise the compression ratio. You can use the Victor Reinz 0.043" multi-layer steel head gasket.
I had the cylinders bored +0.020" in my engine so that they'd be round and true (no taper) for good ring sealing. Always a good idea when you're using an old block.

[Compfreak530]

Ok so heres what i have done so far. i got an old wrangler 4.0 from a 93. tore it down and took All of it to the machine shop.. crank to be grinded for true round. block to be decked .020 . and bored .020 over for true round. all the journals redone for true round and new cam bearings. im getting 677cp pistons in .020 over. going to get new lifters timing gear set reuse stock cam and high volume oil pump. getting head checked cleaned and valves done. the crank was a 4 weight from an 89 and the rods came from same engine. oh and the rods are getting rematchd for true round as well. the machine shop is also gonna get me all the proper bearings for the right size. am i missing anything? anything else i should add? Thanks

[Cheromaniac]

Sounds like you have what you need to build the engine bar the gaskets/seals. You'll need a new 4.0L harmonic balancer and a set of Ford 24lb/hr blue top injectors to complete the build.

[Compfreak530]

OH yeah speaking of which. i remember reading about the harmonic balancer. do i need to have the crankshaft modified to accomidate it? i cant remember was it 1 centimeter off the nose? will the 24lb injectors be enough by themselves to prevent detonation? or do i need to go with a higher fuel pressure? if so whats the cheapest way to raise it safely? thanks again for the help