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Discussion Starter · #1 ·
Hi there I am ordering the last of the bits to refresh/reseal my 1.8 engine. I'm keeping my stock pistons/rods with boost to 8 or so PSI. My question is on the rod bolts and main bolts. Are new stock main bolts ok for boosted applications? They are torque to yield so need to replace right? On the rod bolts TT is out of ARP rod bolts; is there an alternative without modifications (Ford ARP's I have read need to be shaved)? Is there a compatible later model upgrade for these from maybe from the 1.8 G60 or is ARP the only good option if I can find them?
-Hoffa
 

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I believe the mains are old school and they can be used more than once. The rods I'm pretty certain are a one time use.

As for boosted applications, I suspect better bolts are mostly for higher RPM's. On the POS, I used main studs, head studs, and factory rod bolts.

I heard if you are using new rod studs, you'll need the rods resized no matter what you use. My understanding is that the whole will no longer be round.
 

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Discussion Starter · #3 ·
I'm beginning to understand why folks just go ABA or upgrade to a 2.0bubble block vs. rebuilding because you need to go so deep anyways. My idea of refreshing the engine, seals, and bearings with leaving the pistons in the holes looks like it is out the window now. I should have just changed my oil pump and oil a few times and run it! But the upside is I am learning a ton.
 

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Yeah a R&R is always a ton cheaper, once you really start to get into it. I learned this a long time ago…

-Todd
 

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Depends on how much you wanna spend, I swear I’m at like 10k in motor parts alone on mine


Sent from my iPhone using Tapatalk
 

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8 psi? I would run new OEM rod bolts. No need to resize the rod either. At least I didn't. Put many many miles on it after new rod bolts. Two cross country trips as well.
 

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Discussion Starter · #7 ·
Thanks for the replies. I am OK spending money I just hate to waste it by doing something terribly wrong or on things that are not adding any performance value. I would upgrade the pistons and rods if there was a stock sized performance alternative (forged 81mm pistons?) that were better. To do much beyond that though sends you down the path of the machine shop for boring etc. At that point I might as well get a bubble block etc.to beef it up even more.

Deathhare thanks for confirming that replacing the rod bolts can be done without resizing as long as they remain the stock units. Can they be tapped out without causing issues with the pistons in the bores or do the pistons have to come out? I'm sure that proper procedure is to pull them out. I have a full head kit on the way if that is the only safe option.
 

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To clarify, if you used the Ford ARP studs, you had to resize, I agree using the stock ones, no resizing is needed.
 

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As for swaps, there is no way I'm going to throw in a used engine in my car without refreshing the internals. Either way, I'm in in for the same amount of money. I've seen too many used engines/transmissions installed that were junk on clients cars. I figure the cost to refresh it is worth the aggravation that you do not have to go through.
 

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I agree, with less than 10 psi maximum the stock bolts (all around) should be good. Ideally it might be nice insurance to convert everything to high end fasteners, but my understanding is it really isn't necessary unless you plan to heavily abuse it (like track use). However at that point (race level use) there are a lot of other components that will also need upgrading. If you do use non stock hardware then things also need to be rebalanced, yet another added expense. As you say, it can easily escalate.

With a turbo the components that run the biggest risk of failure are head gasket, exhaust valves, pistons, and possibly rods - all depending on the level of boost. Of those the head gasket is the easiest and least expensive upgrade you can do, and I would. A multilayer steel (MLS) gasket is preferred. You can get the G60 MLS very reasonably, or ones from companies like Cometic. You can get stock size forged turbo spec pistons from the aftermarket makers. But at that point you really would be better off boring the cylinders for a perfect fit, so may as well go overbore. Since you are replacing bearings and keeping the stock pistons, why not hone the cylinders and put in new rings? Stainless valves are available in stock sizes, and if you need to rebuild the head (including a valve job) then I would do that - especially on the exhaust side.

A lot of it also depends on what engine management you will be using. The tune (mapping) for fuel and ignition will have a LOT to do with how reliable and trouble free the engine will be. For example if you plan to retain the CIS FI system then I'd definitely upgrade all of the internals. Because you will experience periodic detonation and that will destroy things over time. But if you are going with a modern programmable management system, with a proper tune, then detonation can be better prevented - resulting in less destruction and therefore lesser internal components will survive.
 

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. Can they be tapped out without causing issues with the pistons in the bores or do the pistons have to come out? I'm sure that proper procedure is to pull them out. I have a full head kit on the way if that is the only safe option.
You might could tap them out but you'd have a very hard time getting the new rod bolts in without the rod/piston on the bench.
If you have the head off, then sliding everything out the top is no problem. No need to remove the crank I mean. Then just drop it all in from the top and torque the rod bolts to spec. Put the head back on.
 

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The stud easily is drawn in with the nut. Enough of the stud will come thru so you can put a nut on it. You'll know when it bottoms out. I try to align the edges of the stud so it does not cut new edges in the bolt hole.
 

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The stud easily is drawn in with the nut. Enough of the stud will come thru so you can put a nut on it. You'll know when it bottoms out. I try to align the edges of the stud so it does not cut new edges in the bolt hole.
A great deal off the stud is threadless. Your idea may work with a large spacer to allow it to pull. With the head off its just too easy to not mess with such stuff under a car.
 

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Discussion Starter · #15 · (Edited)
The crank and caps/bearings are all out at the moment. Pistons and rods are still in holes. I'll see if the stock rod bolts tap out easily/safely (I assume they won't just unscrew); if not then everything comes apart including the head and I revisit the plan to include at a minimum MLS HG, ARP rod, main, and head stds. At a max, its a rebore with oversized forged pistons/rods and professional assembly. I appreciate the comments and suggestions thank you!

Oh yeah, my car is running CIS with full Callaway setup including the Microfueler and added injector in the intake. It was running very well with safe AFR's before finding some fine bearing material (most likely due to a stuck Deltagate). I posted pics of the bearings in my main thread and they looked very good still so I was planning to just refresh things rather than a full on rebuild.
 

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Leave one rod nut attached. Unscrew the other nut a few turns. Tap on the stud to see if it comes out. Don't mushroom the end of the stud. Use a punch if needed. Once it's loosened, do the other side. Obviously do not tighten the other nut to pull in the stud. They are not in there that tight.
 

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Discussion Starter · #18 ·
Deahhare- The head is still on I just pullled the motor, flipped it over, and removed the crank to inspect everything bottom end to see if there was any obvious issues. Nothing obvious so the plan was a bearing and seal refresh and stick her back in. The Turbo was loose with bad bearings which could have also been the source of bearing metallics in the oil so had that refreshed by Evergreen.
Butcher- thanks for the suggested process. I am rethinking this plan...
 

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Discussion Starter · #20 · (Edited)
So I am unable to find stock rod bolts for sale or part#. TT, PPInc., GAP, Napa, etc.none list them for sale. PPInc told me that both the stock rod and mains for a 1984 Gti are not stretch and to just re-use them which is why they don't sell them. The Bentley and How to Keep Your Rabbit Alive manual show torque values plus extra degrees turn (implying stretch). I hate to re-use these as they will be the weakest link if truly stretch.
 
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