Drop-in forged internals

[MS3-a(sore)ASS-rex]

Ok so I you're not familiar with the term drop-in internals, it pretty much means that instead of pulling the entire engine and tearing it down and rebuilding it completely, you pull the head and drop the oil pan to swap the pistons, rods, bearings and gaskets (preferably with better head studs). Its done without machine work to the block besides honing the cylinders.

I've done this quite a few times on 4G63's but I dont recall seeing anyone having done it on here. Usually it takes me about a weekend working at a comfortable pace to get this done.

Have any of you done this? And if so what combination of internals, bearings, gaskets and hardware do you recommend for best OEM fitment?

I was considering Eagle H-Beam rods with Wiseco Pistons (stock bore & wrist pin size), with ARP head studs and an OEM gasket kit. Thoughts...opinions?

[trf5000]

No stock block with nitrous?

[MS3-a(sore)ASS-rex]

Originally Posted by trf5000 No stock block with nitrous?

I'd rather be safe than sorry. If I can get away with swapping my internals over a weekend I've got no problem doing it. Car needs to be drivable.

May do a small hit in the neighborhood of 20-25hp on stock block above 3500 rpm but it makes me uneasy haha.

[starscream]

I dont think anyone has really done this because usually the block itself has a hole. So they have to pull.

Also this would only work if you know the engine block is 100% good right? or else you might have a warped deck on the block and you cant machine the block while in the car.

I think just the variables of people haveing blown blocks and all that limits how many would even attempt doing it this way.

[trf5000]

Wouldnt it be just easier to pull the motor?

[MS3-a(sore)ASS-rex]

Originally Posted by starscream I dont think anyone has really done this because usually the block itself has a hole. So they have to pull. Also this would only work if you know the engine block is 100% good right? or else you might have a warped deck on the block and you cant machine the block while in the car. I think just the variables of people haveing blown blocks and all that limits how many would even attempt doing it this way.

I'm a fan of nipping shit in the bud. I'd like to think I wouldn't need to deck the block with 36k on it but it definitely is a variable

Originally Posted by trf5000 Wouldnt it be just easier to pull the motor?

Not at all. It triples your work load

[trf5000]

If you do this, I want to watch.

[MS3-a(sore)ASS-rex]

Originally Posted by trf5000 If you do this, I want to watch.

Sure thing

[crazyp]

I was wondering the same thing. Definitely subbed to I this. I mean really all I want is stronger rods and head studs just like you

[06Speed6]

As long as the bore isnt damaged it would probably be ok, I dont know that it has been done on this engine before because nearly everyone blows then builds or they buy a second block to build then swap.

[MS3KO]

Hmm interesting i hear a lot of ppl dropping internals this way but never on the mzr platform subbd for info

[MS3-a(sore)ASS-rex]

@socks
@SilverDemon
@essejemscraw
@djuosnteisn

Who else has a built block? Lol

[Dano]

Tom u go for it, do a write up and let us know. I wouldn't mind doing this as well. You can get a rigid hone that will remove some bore taper but I don't have an answer on a warped deck or how you'd know it.


Tappin

[Monotonous ONE]

Do that shit

And do a write up

[SilverDemon]

Intersting idea.. I have heard of this being done, but not for performance applications. Not saying that it shouldn't be done for a perfromance application, as long as everything is fine with the head and deck....go for it.

[Chimmike]

I think @dougefresh needs to look at this idea. he doesn't have a hole in his block and he could easily see from below if the bores are okay. It may not be a weekend thing considering you'd have to pull the head, so you're talking timing verification, disconnecting a whole lotta shit, new head gasket, new head studs, etc. etc., but it's doable.

[Domino81]

No machine work at all? Makes me a little nervous.

[MS3-a(sore)ASS-rex]

Originally Posted by Domino81 No machine work at all? Makes me a little nervous.

Why? Boring out a cylinder should never be considered necessary when assembling a forged engine.

[Alpha]

Originally Posted by MS3-a(sore)ASS-rex Why? Boring out a cylinder should never be considered necessary when assembling a forged engine.

I believe you mean when rebuilding an undamaged engine.

Interesting...

[MS3-a(sore)ASS-rex]

Originally Posted by Alpha I believe you mean when rebuilding an undamaged engine. Interesting...

Yes. Unless the cylinder walls have been scored

Edit: unless increasing the displacement is a goal

[Domino81]

Originally Posted by MS3-a(sore)ASS-rex Why? Boring out a cylinder should never be considered necessary when assembling a forged engine.

I just feel like there should be some prep work when a motor needs to accept new parts. Maybe I'm wrong? If I am, I'm fine with that.

[BlueStreak]

I'd be worried about proper bearing clearances...

With my builds, the rod caps had to be shaved down slightly to reduce the size of the bearing bore so the engine wouldn't hemorrhage oil. This issue arose with Carillo rods and OEM bearings.

I believe @djuosnteisn has the same issue and fixed it with a coating on the bearings.

[kmac]

I would want the rotating assembly balanced, but that's me. I wouldn't advise it. I'm not saying it won't work . I would just prefer it balanced.

[MS3-a(sore)ASS-rex]

Originally Posted by BlueStreak I'd be worried about proper bearing clearances... With my builds, the rod caps had to be shaved down slightly to reduce the size of the bearing bore so the engine wouldn't hemorrhage oil. This issue arose with Carillo rods and OEM bearings. I believe @djuosnteisn has the same issue and fixed it with a coating on the bearings.

This is the kind of info I made this thread for

[trf5000]

Yea i think the bearings would be the biggest challenge. Would be a pain in the ass trying to set the clearences with everything still in the car wouldnt it?

[MS3-a(sore)ASS-rex]

Originally Posted by trf5000 Yea i think the bearings would be the biggest challenge. Would be a pain in the ass trying to set the clearences with everything still in the car wouldnt it?

No, the bearings should already be manufactured to the correct clearance.

[06Speed6]

The crank should already be balanced, relatively speaking. Bearing clearances could be an issue because you wouldnt know if the crank is worn.

I havent tried this in a car engine, but on small engines I have unbolted the rod caps in the middle of the down stroke, rotated the crank to bdc, measured the bearing clearance, then rotated the crank back up to the rod and bolted it back in. Its not real hard to do and it would let you know if you need to coat the bearings or source some oversize bearings.

[Dano]

Originally Posted by MS3-a(sore)ASS-rex No, the bearings should already be manufactured to the correct clearance.

they should but they are absolutely not guaranteed. Working with my buddy now on an 08 STI block. OE rod bearing clearances were within spec IIRC .0015-.0020...he threw in some ACL bearings on the Eagle H-beams and the clearance was .0007-.00010.

long story short that motor would have spun the bearings in .003 seconds when it was started. lol

don't know if the newer coating on the 08 STI crank made the clearance tight but it would have been ugly real fast.

he then ordered some under sized bearings from ACL. .001 under sized IIRC which should put him at .0017-.0020

this is all new to me but I think I have the correct amount of zeros in those numbers

This was all done with a bore gauge not plasti guage so no way to do that with the motor in the car....at least not on the mains.

[06Speed6]

He isnt swapping mains, the rod bearings can be measured.

[JacksonMS30]

Interested in this as well.

By the waty, is there a benefit to increasing displacement?

[Dano]

Originally Posted by 06Speed6 He isnt swapping mains, the rod bearings can be measured.

roger that

[4G63]

God damn Tom you got a lot of shit back on that car already! Can't wait to see this play out. All platforms need pioneers and I'm glad ur taking this head on should be good stuff. This is formerly AdrenalineRush btw.

[Dano]

Originally Posted by kmac I would want the rotating assembly balanced, but that's me. I wouldn't advise it. I'm not saying it won't work . I would just prefer it balanced.

may not be ideal but the crank/pully is fairly well balanced from Mazda...you can then balance your new rods and pistons which are very much less critical since they are not part of the rotating assembly.

I wouldn't rev this type of swap out to 8K by any means but the OE redline or 7K ish should be fine.

no?

[Brian MP5T]

Subs

[Bucker]

Just a note, Ill be tossing on my Zex kit with a 35hp nozzle at the end of the month on stock block/ 25PSI K04 and dont have too much concern. Are you intending to run more nitrous than that?

[MS3-a(sore)ASS-rex]

Originally Posted by Bucker Just a note, Ill be tossing on my Zex kit with a 35hp nozzle at the end of the month on stock block/ 25PSI K04 and dont have too much concern. Are you intending to run more nitrous than that?

No more would be run on the stock block/turbo for sure but down the road a monster hit would be nice for that unsuspecting corvette on the highway.

I'd be doing more so that I'd be able to spray at a lower rpm without fear of bending or ejecting a rod.

Also, connecting rods generally are balanced +/- 1 gram

Originally Posted by 4G63 God damn Tom you got a lot of shit back on that car already! Can't wait to see this play out. All platforms need pioneers and I'm glad ur taking this head on should be good stuff. This is formerly AdrenalineRush btw.

Oh shit hey alex lol. Yea man I'm playing no games this time around

[kmac]

Originally Posted by Dano may not be ideal but the crank/pully is fairly well balanced from Mazda...you can then balance your new rods and pistons which are very much less critical since they are not part of the rotating assembly. I wouldn't rev this type of swap out to 8K by any means but the OE redline or 7K ish should be fine. no?

Anything that moves should be bal . Imbalances cause harmonic resonance and that's what destroys everything . You should even bal with a lightened clutch setup.

[troubled81]

If you do this i suggest the CP pistons as i put them in my motor and they do not require you to bend the piston squirters. (i have read that the Wiseco pistons do) The do run a tight .0035 wall clearance so without over boring it they might be loud untill they warm up.

As for the rods i went with K1 with stock OEM bearings and so far everything is good. I checked the clearances of all of them (i forget now what each was) and they all were within spec.

[Dano]

Originally Posted by MS3-a(sore)ASS-rex Also, connecting rods generally are balanced +/- 1 gram

Yup. The eagles for the sti build, 3 were identical with one being one gram heavier

There is also balancing each end of the rod and we will be doing that and getting them to within .5 of a gram iirc. Getting the whole rotating ass balanced as well. Pully-crank-FW

This is also going to be a high compression setup, somewhere around 9.5 iirc

Should be fun.

For me, I like to put in some gen2 pistons if you can get them cheap, w k1 rods and call it a day.

For you and nitros I would replace the pistons fo sho.




Tappin

[starscream]

Heres a way you can check the deck of the block yourself at home

Blueprint 108 - inspect the deck - YouTube

Blueprint 108 - inspect the deck - YouTube