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ZRP Forged Conrods

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e21Mark

Original Poster:

8,878 posts

93 months

Thursday 22nd December 2016
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I'm rebuilding the s14 engine in my BMW E30 M3 and have been looking at replacing the OE conrods. In fact, I have also been considering shot peening and balancing the OE rods as well. Ideally I would opt for Arrow rods, as they're tried and tested, but at £1 100 they're an added expense I simply cannot afford. Rebuilding an s14 isn't cheap and I have already spent several £k on new Schrick cams, head work, lighter flywheel & an upgrade to standalone ignition.

Anyway, after ignoring the various Chinese options I found these from ZRP and wondered if anyone else had used them? http://zrp-rods.co.uk/bmw-m3-s14-b23-s14-b25-conne...

Obviously I would use best quality bearings and ARP bolts but am still undecided between the ZRP and overhauling the OE rods?

It's important I get this build right first time but I am at my limit when it comes to budget.

stevieturbo

12,529 posts

167 months

Thursday 22nd December 2016
quotequote all
e21Mark said:
I'm rebuilding the s14 engine in my BMW E30 M3 and have been looking at replacing the OE conrods. In fact, I have also been considering shot peening and balancing the OE rods as well. Ideally I would opt for Arrow rods, as they're tried and tested, but at £1 100 they're an added expense I simply cannot afford. Rebuilding an s14 isn't cheap and I have already spent several £k on new Schrick cams, head work, lighter flywheel & an upgrade to standalone ignition.

Anyway, after ignoring the various Chinese options I found these from ZRP and wondered if anyone else had used them? http://zrp-rods.co.uk/bmw-m3-s14-b23-s14-b25-conne...

Obviously I would use best quality bearings and ARP bolts but am still undecided between the ZRP and overhauling the OE rods?

It's important I get this build right first time but I am at my limit when it comes to budget.
I'd never heard of them until a couple of years ago at Autosport. Then I have noticed a few places using them who post on social media etc and havent noticed any bad reports. If you google....they do sort of suggest they are based in Greece, although other googles suggest they're basically Chinese. But then what isnt made in China these days.
As long as the right quality controls are in place nothing wrong with it.

Any of the places selling cheaper stuff, will ultimately nearly always be Chinese anyway regardless of name. Even cheap no brand stuff seems to hold up well though, but as you say, defo use proper ARP bolts although ZRP seem to supply these anyway

e21Mark

Original Poster:

8,878 posts

93 months

Thursday 22nd December 2016
quotequote all
stevieturbo said:
e21Mark said:
I'm rebuilding the s14 engine in my BMW E30 M3 and have been looking at replacing the OE conrods. In fact, I have also been considering shot peening and balancing the OE rods as well. Ideally I would opt for Arrow rods, as they're tried and tested, but at £1 100 they're an added expense I simply cannot afford. Rebuilding an s14 isn't cheap and I have already spent several £k on new Schrick cams, head work, lighter flywheel & an upgrade to standalone ignition.

Anyway, after ignoring the various Chinese options I found these from ZRP and wondered if anyone else had used them? http://zrp-rods.co.uk/bmw-m3-s14-b23-s14-b25-conne...

Obviously I would use best quality bearings and ARP bolts but am still undecided between the ZRP and overhauling the OE rods?

It's important I get this build right first time but I am at my limit when it comes to budget.
I'd never heard of them until a couple of years ago at Autosport. Then I have noticed a few places using them who post on social media etc and havent noticed any bad reports. If you google....they do sort of suggest they are based in Greece, although other googles suggest they're basically Chinese. But then what isnt made in China these days.
As long as the right quality controls are in place nothing wrong with it.

Any of the places selling cheaper stuff, will ultimately nearly always be Chinese anyway regardless of name. Even cheap no brand stuff seems to hold up well though, but as you say, defo use proper ARP bolts although ZRP seem to supply these anyway
Just had a long chat to the guys at TSR who supply and use them in their VAG turbo builds. I was pretty candid about my concerns re quality and they said they used them in all their builds and had regularly seen 500+bhp with no issues. Anyway, they're shipping a set out to me so we shall soon see I guess?

Luther Blissett

292 posts

52 months

Thursday 22nd December 2016
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I think Robson's in Coventry would be worth a call.

e21Mark

Original Poster:

8,878 posts

93 months

Thursday 22nd December 2016
quotequote all
Luther Blissett said:
I think Robson's in Coventry would be worth a call.
Unfortunately they don't do BMW.

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Boosted LS1

16,154 posts

180 months

Thursday 22nd December 2016
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Op, is there a weakness with the current rods? Presumably those are steel and maybe would be fine if fitted with quality bolts. Obviously if you're upping the rpm's fresh rods would be a must.

227bhp

5,191 posts

48 months

Saturday 24th December 2016
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e21Mark said:
Just had a long chat to the guys at TSR who supply and use them in their VAG turbo builds. I was pretty candid about my concerns re quality and they said they used them in all their builds and had regularly seen 500+bhp with no issues. Anyway, they're shipping a set out to me so we shall soon see I guess?
They were hardly going to say no, they're a bit iffy.
We shall see? Not unless you know what you are looking for and the equipment to do it.

I've used them and checked as much as I could, I don't have any equipment to check for strength such as xray etc, and they've been fine, they weighed in at the lightest i've ever used out of Arrows, Robson, PEC, Crower, Maxpeeding (yes really)
Most budget rods in the UK (PEC & ZRP) are made in China, it doesn't seem to be an issue.

As per above, on a recent budget build we got some Maxpeeding rods in to see what they were like, I couldn't fault them. £165 per set delivered and they were balanced much more accurately than Robson (that isn't difficult to beat). 3 were bang on identical, one just .1g heavier, to give you an idea of how much that is it's the corner torn off a tissue hanky about 10mm square, OE tolerances were about +-5g. If I was being picky it didn't look like they'd used ARP lube on the bolts, but it would have made bugger all difference.
They haven't made a break for freedom yet anyhow....

227bhp

5,191 posts

48 months

Saturday 24th December 2016
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Boosted LS1 said:
Op, is there a weakness with the current rods? Presumably those are steel and maybe would be fine if fitted with quality bolts. Obviously if you're upping the rpm's fresh rods would be a must.
There is much more to it than that.
Better material aside, often new rods have better cap location and are lighter.
The old rods could have been to hell & back, be stretched, bent, twisted, oval bearing housings etc. What backyard builder has the knowledge, ability and equipment to check for that?

When the size of your wallet exceeds what is in your head you replace, it isn't worth the risk.

stevieturbo

12,529 posts

167 months

Saturday 24th December 2016
quotequote all
227bhp said:
There is much more to it than that.
Better material aside, often new rods have better cap location and are lighter.
The old rods could have been to hell & back, be stretched, bent, twisted, oval bearing housings etc. What backyard builder has the knowledge, ability and equipment to check for that?

When the size of your wallet exceeds what is in your head you replace, it isn't worth the risk.
Problem is...with some Chinese rods, they can be poor, out of round, perhaps fake "ARP" bolts etc etc and actual material...who knows what they use sometimes

Whereas OEM are of known quality and if they've been in an engine a long time, are clearly fully tried and tested to be reliable.

So there are pros/cons both ways, hence when some of these rods are so cheap there are genuine concerns.

Although most of the Chinese rods out there today, seem to be pretty good. As with everything their first few months, years of anything they dive into can be pretty bad. Chinese turbos at the start were absolute rubbish, these days many use them very reliably and they really are so so cheap.
Likewise their intercoolers....none are superb performers, but for the money they're still hard to beat.

But I've never really heard any bad reports about ZRP stuff. No doubt they'll be at Autosport again this year, so maybe pop in and have a look.

227bhp

5,191 posts

48 months

Saturday 24th December 2016
quotequote all
stevieturbo said:
227bhp said:
There is much more to it than that.
Better material aside, often new rods have better cap location and are lighter.
The old rods could have been to hell & back, be stretched, bent, twisted, oval bearing housings etc. What backyard builder has the knowledge, ability and equipment to check for that?

When the size of your wallet exceeds what is in your head you replace, it isn't worth the risk.
Problem is...with some Chinese rods, they can be poor, out of round, perhaps fake "ARP" bolts etc etc and actual material...who knows what they use sometimes

Whereas OEM are of known quality and if they've been in an engine a long time, are clearly fully tried and tested to be reliable.

So there are pros/cons both ways, hence when some of these rods are so cheap there are genuine concerns.

Although most of the Chinese rods out there today, seem to be pretty good. As with everything their first few months, years of anything they dive into can be pretty bad. Chinese turbos at the start were absolute rubbish, these days many use them very reliably and they really are so so cheap.
Likewise their intercoolers....none are superb performers, but for the money they're still hard to beat.

But I've never really heard any bad reports about ZRP stuff. No doubt they'll be at Autosport again this year, so maybe pop in and have a look.
This is true, I think the fake ARP rod bolt thing (if it ever existed) is long gone, but regarding price - a lot of it is mark up. I seem to remember years ago someone found out a Chinese rod was circa £10. I don't know how Arrows manage to get away with selling theirs for what they do - I couldn't keep a straight face offering those prices.
The other thing which goes against them is if a motor lets go then the rod is blamed, it's rarely the cause. Unless it's a turbo'd MX5 lol, I don't think twice about putting Maxpeeding rods in one of those. They do put copies of certificates of conformoties on their ads, but a kid could have drawn them up.

stevieturbo

12,529 posts

167 months

Saturday 24th December 2016
quotequote all
227bhp said:
This is true, I think the fake ARP rod bolt thing (if it ever existed) is long gone, but regarding price - a lot of it is mark up. I seem to remember years ago someone found out a Chinese rod was circa £10. I don't know how Arrows manage to get away with selling theirs for what they do - I couldn't keep a straight face offering those prices.
The other thing which goes against them is if a motor lets go then the rod is blamed, it's rarely the cause. Unless it's a turbo'd MX5 lol, I don't think twice about putting Maxpeeding rods in one of those. They do put copies of certificates of conformoties on their ads, but a kid could have drawn them up.
True, if they sold the rods too cheap.....everyone would avoid. If they listed the exact same rod at £2, or £300 everyone would think it ok. And no doubt there are people selling the same rod at even higher prices, perhaps with their name laser etched onto them. A name adds cost lol

That said...for a build making good power or pulling a lot of rpm's, I'd still want a proper branded rod in there unless cheaper alternatives are fully tried and tested at that level.

But in and around 500hp shouldnt trouble any of them, unless it needs to pull 9-10krpm to achieve it.

Boosted LS1

16,154 posts

180 months

Saturday 24th December 2016
quotequote all
Well, I doubt very much the OP's current rods are bent, mangled or twisted otherwise his shells and pistons would have had something to say about it. If he's on a budget and sticking to factory rpm's there should be no real need to install something untested. The stock rods will have been tested mercilessly by the manufacturer and along with a bolt upgrade will probably last for a very long time. They may be a lot lighter to. Horses for courses.

OP, are your current rods bushed?

Edited by Boosted LS1 on Saturday 24th December 17:19

227bhp

5,191 posts

48 months

Saturday 24th December 2016
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Unless you know him intimately you can't vouch for his knowledge and diligence where engines are concerned.
Having seen one, but not weighed it I can tell you comparing a modern H beam to an OE S14 rod is akin to comparing Red Rum to a cart horse.
Whilst it's not as old as Red Rum, thats an engine that was put together some 26yrs ago now, that is already a very long time.
They are hardly untested, it's not like someone just brought them out last week....

Boosted LS1

16,154 posts

180 months

Saturday 24th December 2016
quotequote all
You misunderstand me. I'm saying that the engine (it's rods etc) has been endurance tested by the manufacturer and it's thresholds are well understood. The 'new' brand of rod poses a risk in itself and probably isn't needed.

e21Mark

Original Poster:

8,878 posts

93 months

Saturday 24th December 2016
quotequote all
227bhp said:
They were hardly going to say no, they're a bit iffy.
No, but I was able to ask about specific builds/applications and research TSR and their cars in an effort to allay some initial fears regarding fit and quality. I also confirmed with ARP that they do supply their bolts.

My main reason for replacing the rods is their being over 26 years old and that they've done over 100k miles. I'm fitting CP pistons, ARP studs/bolts, Schrick etc and am already a good few £k in. Yes, I would have preferred Arrow rods but TSR did me an excellent deal and the money saved will cover mapping. I have limited funds and am trying to get the best bang for my buck, whilst maintaining reliability.

My engine builder will be checking the new rods and will let e know if he has any reason to suspect their fit and quality. These rods are commonly used in Greece and there are several VAG and Mini tuners using them without issue.


Edited by e21Mark on Saturday 24th December 20:28

stevieturbo

12,529 posts

167 months

Saturday 24th December 2016
quotequote all
e21Mark said:
No, but I was able to ask about specific builds/applications and research TSR and their cars in an effort to allay some initial fears regarding fit and quality. I also confirmed with ARP that they do supply their bolts.

My main reason for replacing the rods is their being over 26 years old and that they've done over 100k miles. I'm fitting CP pistons, ARP studs/bolts, Schrick etc and am already a good few £k in. Yes, I would have preferred Arrow rods but TSR did me an excellent deal and the money saved will cover mapping. I have limited funds and am trying to get the best bang for my buck, whilst maintaining reliability.

My engine builder will be checking the new rods and will let e know if he has any reason to suspect their fit and quality. These rods are commonly used in Greece and there are several VAG and Mini tuners using them without issue.


Edited by e21Mark on Saturday 24th December 20:28
As said before...unless you're pulling serious rpm's, ie 9k+ or say, 7, 8, 900hp etc then the likes of Arrow, Carillo etc are not really required vs some of the cheaper alternatives.

99hjhm

259 posts

106 months

Saturday 24th December 2016
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e21Mark said:
Unfortunately they don't do BMW.
Not even to a pattern? Prefer Robson to China and far cheaper than Arrow.

Boosted LS1

16,154 posts

180 months

Sunday 25th December 2016
quotequote all
e21Mark said:
227bhp said:
They were hardly going to say no, they're a bit iffy.
No, but I was able to ask about specific builds/applications and research TSR and their cars in an effort to allay some initial fears regarding fit and quality. I also confirmed with ARP that they do supply their bolts.

My main reason for replacing the rods is their being over 26 years old and that they've done over 100k miles. I'm fitting CP pistons, ARP studs/bolts, Schrick etc and am already a good few £k in. Yes, I would have preferred Arrow rods but TSR did me an excellent deal and the money saved will cover mapping. I have limited funds and am trying to get the best bang for my buck, whilst maintaining reliability.

My engine builder will be checking the new rods and will let e know if he has any reason to suspect their fit and quality. These rods are commonly used in Greece and there are several VAG and Mini tuners using them without issue.


Edited by e21Mark on Saturday 24th December 20:28
I'm sure you'll be fine but for info.

I ran a saab turbo to 400'000 on stock rods. Your're mileage is peanuts but if bmw are known for st engines you should change your rods. They'll be well twisted and bent by now according to the doomslayers, lol.

As an aside, you'll need to rebalance the engine but all should work well for you.

227bhp

5,191 posts

48 months

Sunday 25th December 2016
quotequote all
e21Mark said:
No, but I was able to ask about specific builds/applications and research TSR and their cars in an effort to allay some initial fears regarding fit and quality. I also confirmed with ARP that they do supply their bolts.

My main reason for replacing the rods is their being over 26 years old and that they've done over 100k miles. I'm fitting CP pistons, ARP studs/bolts, Schrick etc and am already a good few £k in. Yes, I would have preferred Arrow rods but TSR did me an excellent deal and the money saved will cover mapping. I have limited funds and am trying to get the best bang for my buck, whilst maintaining reliability.

My engine builder will be checking the new rods and will let e know if he has any reason to suspect their fit and quality. These rods are commonly used in Greece and there are several VAG and Mini tuners using them without issue.


Edited by e21Mark on Saturday 24th December 20:28
You never said you had an engine builder, it should be his call really, but if everything checks out then you'll be fine. It's a bit too late for this discussion as it sounds like you've already ordered the stuff, but ZRP do a range of rods for seperate engines: Standard H beam, HD and longer ones for non standard pistons, HD being heavy duty of course.
Did you actually ring Robson to check?


227bhp

5,191 posts

48 months

Sunday 25th December 2016
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Boosted LS1 said:


As an aside, you'll need to rebalance the engine
No he won't, it's an I4, not a V8.