Mystery Stroker Motor

Newbies, and basic Stroker Recipes... Get started with your first stroker here!!
DillyFPV
Posts: 8
Joined: November 8th, 2022, 6:58 am
Stroker Displacement: 4.7
Vehicle Year: 2001
Vehicle Make: jeep
Vehicle Model: cherokee

Mystery Stroker Motor

Post by DillyFPV »

Hey guys,

So I recently picked up a 4.7 stroker on marketplace for $100. The story goes: guy I bought it from built it about 8 years ago with help from you fine folks on this forum, it cost him about 4k and it ran great. The jeep rusted out so the engine was pulled and then sat on a stand for a few years and he estimates that he put about 50k miles on it before it was pulled. He sounded knowledgeable, but could not remember any specifics because it had been so long since he built it. I was sceptical but the guy just needed it gone and he was happy with my $100 offer so what the hell. I got it back to the garage and it turned over, felt like it had good compression, and once torn down a bit, obviously had custom pistons, so I believe it is actually a $100 stroker.

So I am a reasonable competent shade tree mechanic, but I am not an engine builder. I'd like to just toss it in my 2001 cherokee and call it a day, but maybe it's not going to be that easy. First off, this motor is from out of a mid 90's jeep, so I need to put a 00-01 head on it unless I want to convert to a dizzy and swap manifolds, which I don't. Secondly, I see a some piston scoring on the cylinder walls. I wish there was none at all but maybe I don't care. It's just enough were I can faintly feel it on my thumb nail when I scratch across it on a couple of the cylinders. Is that a lot or is it a little? Thirdly, If I throw a later 0331 tupy head on it, do I need to worry about where the compression ratio is going to end up? I do know that he said he built it to run on 87, but I don't know what he did to his head, or how much he decked the block, or what head gasket he used(i guess I could measure?) Also, do I need to pay attn to push rod length because he mentioned he remembered something about shims, and is has some variety of comp cam in it.

I don't have a ton of time or money to spend on this, but I also don't want to slap something together that is going to self destruct. What do you guys think my options are?
DillyFPV
Posts: 8
Joined: November 8th, 2022, 6:58 am
Stroker Displacement: 4.7
Vehicle Year: 2001
Vehicle Make: jeep
Vehicle Model: cherokee

Re: Mystery Stroker Motor

Post by DillyFPV »

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Cheromaniac
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Re: Mystery Stroker Motor

Post by Cheromaniac »

It looks like you have a fairly decent motor. The scoring on the cylinder wall looks very fine. At worst you might see slightly higher oil consumption than normal.
You should be good to go if you throw an '02+ TUPY head on it. The chamber size is the same 57-58cc as the earlier heads so the CR won't change. After you've assembled the valvetrain, check the lifter preload (should be 0.030"-0.060" or half to one full turn of the rocker arm bolt from the zero lash point) and adjust if necessary.
1992 XJ 4.6 I6 - 5MT - Stroker build-up, Stroker "recipes" Sold
1995 Mustang GT - 4AT - Modded Sold
2006 Mustang GT - 5MT - Modded Midlife Crisis Car :mrgreen:
DillyFPV
Posts: 8
Joined: November 8th, 2022, 6:58 am
Stroker Displacement: 4.7
Vehicle Year: 2001
Vehicle Make: jeep
Vehicle Model: cherokee

Re: Mystery Stroker Motor

Post by DillyFPV »

Hey, thanks for the reply. I'm happy to hear that you don't think that amount of scoring is going to me a problem. I knew that piston slap and scoring was a common very problem with these motors, but just wasn't sure what was tolerable. I remember now the guy saying that this block was already .006 over, so not sure if boring or honing and re-ringing is even an option. And then my pistons might be too undersized making the problem worse right? I'm just speculating, not an engine builder.

What about headgasket thickness/brand? Is there a specific one you guys like to use? And I was thinking of grabbing one of these heads: https://www.ebay.com/itm/125590007521?h ... R6r41qeKYQ
Or should I spend a little more and go with a reman?
Randy Bobandi
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Re: Mystery Stroker Motor

Post by Randy Bobandi »

Holy cow, $425 for a junkyard TUPY head? There are tons of TUPY heads on Car-Part for $100.

For science...Which cylinders are beat up the most? Are all of your cylinders scuffed like that? Or are some worse than others.
DillyFPV
Posts: 8
Joined: November 8th, 2022, 6:58 am
Stroker Displacement: 4.7
Vehicle Year: 2001
Vehicle Make: jeep
Vehicle Model: cherokee

Re: Mystery Stroker Motor

Post by DillyFPV »

Yeah, I hate to pay that much for a head when I can get a whole engine for that or less, but at least I know its a tupy and its been cleaned and tested. Saves some time. But is there a year/model that is guaranteed to have a tupy 0331? on car-part you know what the head is off of obviously, but thats about it, but I guess I'd rather spent 150 and take it to a machine shop and have them look it over.

And the scoring was present on all 6 cylinders, the center two may have been marginally worse, but just barely.
Randy Bobandi
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Re: Mystery Stroker Motor

Post by Randy Bobandi »

02'-06' Wrangler and 02'-04' Grand Cherokee heads are TUPY castings. Though some folks have reported plain 0331 heads in their 02' Jeeps. So they may have made the change during 2002 production. 03'-06' is no doubt TUPY. 02' you might want to call the seller.
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Cheromaniac
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Re: Mystery Stroker Motor

Post by Cheromaniac »

DillyFPV wrote: November 10th, 2022, 6:29 amI remember now the guy saying that this block was already .006 over, so not sure if boring or honing and re-ringing is even an option. And then my pistons might be too undersized making the problem worse right? I'm just speculating, not an engine builder.
If the cylinders are already +0.060", a rebore may not be possible and a rehone would require a new set of pistons. To me, the scuffing on the cylinder wall doesn't look bad. If it doesn't catch your fingernail, don't worry about it.
1992 XJ 4.6 I6 - 5MT - Stroker build-up, Stroker "recipes" Sold
1995 Mustang GT - 4AT - Modded Sold
2006 Mustang GT - 5MT - Modded Midlife Crisis Car :mrgreen:
Russ Pottenger
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Vehicle Model: Cherokee

Re: Mystery Stroker Motor

Post by Russ Pottenger »

I’d consider running a ball hone through the cylinders which won’t remove any material but It will break the glaze and put a fresh cross hatch and drop in a new set of Hastings 2M 667 rings and call it done.
DillyFPV
Posts: 8
Joined: November 8th, 2022, 6:58 am
Stroker Displacement: 4.7
Vehicle Year: 2001
Vehicle Make: jeep
Vehicle Model: cherokee

Re: Mystery Stroker Motor

Post by DillyFPV »

Update: I tracked down a tupy 0331 at the junkyard for $150. Its at the machine shop now getting worked over. Also spoke to them about the piston scoring issue and they agree with you guys that it will probably be fine to run it as-is, but it wouldn't be a bad idea to hone and re-ring. I'm not sure I want to take that on myself as I don't really have the tools, experience, or time to figure it out right now. He quoted about $900 to do that for me along with new rod and main bearings. Given the budget nature of this build, I'm considering just slapping the head on as-is. Kinda torn tho, would be nice to have every thing all freshened up. Also, I'm wondering if that is a normal amount of scoring for 50k miles. Maybe its possible that the pistons are a little over or undersized, and having a machine shop go through it might reveal that there was something amiss with the build.

Also, I ordered a victor 54249 headgasket that everyone on here seems to use but received a Mahle. Its got 54249 on it but the silicone is black instead of blue like most others that I see. Do I care? Run it or exchange?

As for head bolts, I found some APR on sale. Or does it just not matter and should I go with cheap oem?
Randy Bobandi
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Re: Mystery Stroker Motor

Post by Randy Bobandi »

DillyFPV wrote: November 22nd, 2022, 5:09 pm they agree with you guys that it will probably be fine to run it as-is, but it wouldn't be a bad idea to hone and re-ring. I'm not sure I want to take that on myself as I don't really have the tools, experience, or time to figure it out right now.

Also, I ordered a victor 54249 headgasket that everyone on here seems to use but received a Mahle. Its got 54249 on it but the silicone is black instead of blue like most others that I see. Do I care? Run it or exchange?

As for head bolts, I found some APR on sale. Or does it just not matter and should I go with cheap oem?
You don't have a drill? All you need to do to hone the cylinders is pop out the pistons/rods and then rip the ball hone up and down each cylinder. Of course some clean up afterwards. You'd be amazed how just 5 seconds of the ball hone refinishes the cylinder.

The Mahle and Victor Reinz head gaskets are the same. They're manufactured by Mahle for Dana Spicer then sold under the Victor Reinz brand name. The coating is Nitrile.

I wouldn't use the ARP bolts. They don't feature the studs for the injector rail or the ground strap. Cheap OEM are not exactly cheap quality. They are made from the same material as the ARP bolts. They are Grade 9 ASTM A325 heat treated structural steel. $30 for MAHLE GS33414 is an insane deal for 14 1/2" 180,000 PSI fasteners.
DillyFPV
Posts: 8
Joined: November 8th, 2022, 6:58 am
Stroker Displacement: 4.7
Vehicle Year: 2001
Vehicle Make: jeep
Vehicle Model: cherokee

Re: Mystery Stroker Motor

Post by DillyFPV »

Haha, yes I have a drill. I guess I am being lazy, I should just do it myself. I know its not that hard, its just a little intimidating because I've never done it before. And I gotta buy a few odds and ends but I don't mind spending a little money on tools I guess. What ball hone should I get? Am I going to have to adjust the ring gap with those m2 667 rings? Should I measure my actual bore size before ordering rings or are those gonna be the rings I want regardless?
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Cheromaniac
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Posts: 3180
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Stroker Displacement: 4563cc
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Vehicle Model: Cherokee
Location: Cyprus
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Re: Mystery Stroker Motor

Post by Cheromaniac »

You'll probably just need another set of +0.060" rings but check the bore size anyway before ordering.
TJBUD
Where's the "any" key?
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Posts: 27
Joined: April 20th, 2022, 9:32 am
Stroker Displacement: 4.7
Vehicle Year: 1998
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Re: Mystery Stroker Motor

Post by TJBUD »

I found rockauto.com to be a great source for the head bolts on my 98 stroker. I used enginetech HB201 for $18. I don’t see these on the site today but they have Mahle ($23), Felpro ($331), VIctor-R ($32). TJBUD
TJBUD
Where's the "any" key?
Where's the "any" key?
Posts: 27
Joined: April 20th, 2022, 9:32 am
Stroker Displacement: 4.7
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Re: Mystery Stroker Motor

Post by TJBUD »

Felpro $31, sorry
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