Spool Imports Conrods

[slowhoon]

I'm considering the Spool Imports conrods for my 170 after I had a rod bolt (ARP) break a couple of months ago.
https://www.spoolimports.com/spool-ford-200-conrods

Research tells me that 200 conrods are the same as those found in the 170, so I'm wondering if anyone has had any actual experience with Spool conrods (good or bad) before I go ahead with the purchase. At the very least they have 3/8th bolts as opposed to the standard 5/16th items.

Cheers, Alan.

 

[rocklord]

I believe the conrods you listed are for the Australia 200 Crossflow engine. Those conrods are 6.27" in length, as the US 200 rods are 4.715" in length.
Contact Spool Imports to make sure what engine these conrods fit.

 

[aussie7mains]

I believe the conrods you listed are for the Australia 200 Crossflow engine. Those conrods are 6.27" in length, as the US 200 rods are 4.715" in length.
Contact Spool Imports to make sure what engine these conrods fit.

Correct, often used with the 250 crank and custom pistons to give improved rod ratio.

 

[slowhoon]

Thanks for the quick repliesI did ask the following question:

Which version of the 200 are these for? That is, pre-crossflow or one of the crossflow developments.

And they answered:

These are pre-xflow but we recommend them for 250 Xflow as well with our pistons that are designed to work with them

But I clearly didn't ask a good enough question! I'll get onto that (I'm in NZ by the way).

 

[drag-200stang]

It would be nice if they would put up the rod Lenths, that would take out some guessing.

 

[Jmustang_65]

If you need US spec. I added Toyota 1jz Conrods with custom pistons to my build. I had to offset grind the crank a bit.
Spool imports sells them too 1jz Rods.

​

Length	Notes	Wt	Jrnl	Pin	BE	PE
4.931	all 1JZ models	555	Stock	22mm	1.020	1.000

Local member has a set for sale.

For Sale Thread 'Toyota 1JZ Rodz'

Feb 28, 2024

Got these rods I was going to use for a 200. I’m sure you guys know the work to put these on. I bought them for like 700 dollars cause of tax and shipping. Putting these up for 500 plus whatever the shipping will be. Thank you.

I kept forgetting to list these here; you guys are way more technical and more willing to put work on your motors.

• Cesarvi17
• Replies: 0
• Forum: Buy, Sell, or Trade - Small Six

• 

​

 

[slowhoon]

Spool Imports replied (some weeks ago in truth) and as Rocklord said, they are 6.27" in length.

So for now, I'll get the engine rebuilt with standard rods and remember to replace the rod bolts every few race meetings. Or at the very least check they are torqued up correctly.

Attached are some photos of the damage. Feel free to offer up any suggestions as to what might have gone wrong (rod bolt breaking or something else).

 

[drag-200stang]

I do not think that it is the bolts. I think that either detonation or water hydro locking it . Well that is my guess.

 

[Walken100]

No expert and probably little help but a couple of smart people I know say "It's not the rods fault". Not that a rod can't fail on its own but that the failure is typically caused by something else.

Just out of curiosity do you have pictures of the tops of the pistons? Those rods look like they been hammered by the god of thunder.

 

[Frank]

Feel free to offer up any suggestions as to what might have gone wrong (rod bolt breaking or something else).

A spun bearing trying to seize the crank will snap a rod. When the bearing starts gripping the crank, the crank journal's surface rotation is applying huge twisting force on the rod. Sometimes the engine will seize before the rod breaks, sometimes not. The higher the rpm and load the more risk the rod snaps, creating instant destruction.

The variety of damage there does leave a mystery though. Spun bearing may break the one, but does not directly explain the other bent one. . . Humm

 

[slowhoon]

Thanks again for the continuing replies. Here are the photos I took of the pistons a few weeks back - the close up is of number 6, with witness marks from the inlet and exhaust valves.
A local engine reconditioner checked out the pistons earlier today and says that three of the pistons are okay to reuse. He told my mechanic friend but didn't say which three (it was in a long conversation about several engines). I'm guessing 2, 3 and 4 as the rods for 1 and 5 are bent. It's not obvious in any photos but number 2 rod looks compressed and slightly twisted.

I should add that the engine runs a 2v head with triple 45DCOE Webers. It was tuned on a dynomometer and the AFR was (excuse me for not writing this down at the time) around 12:1 - 13:1.

 

[slowhoon]

A spun bearing trying to seize the crank will snap a rod. When the bearing starts gripping the crank, the crank journal's surface rotation is applying huge twisting force on the rod. Sometimes the engine will seize before the rod breaks, sometimes not. The higher the rpm and load the more risk the rod snaps, creating instant destruction.

The variety of damage there does leave a mystery though. Spun bearing may break the one, but does not directly explain the other bent one. . . Humm

Here are a series of photos of the crankshaft - specifically trying to show where number 6 conrod took a disliking to its job. Unsurprisingly there is not enough of the number 6 big end bearings to even allow identification of them. In the fifth photo can be see the big ends from number 5. They were down to the copper and one tang was missing, but they had not spun. The other four big end bearings looked okay to me but my mechanic friend considered they were quite worn.

 

[slowhoon]

I do not think that it is the bolts. I think that either detonation or water hydro locking it . Well that is my guess.

That makes sense, but the head gasket looked to be intact and the engine reconditioner (as mentioned above) has checked over the head and says that other than a couple of loose valve guides it all looks okay.
I'll chase up which valve guides and whether they did any crack testing or vacuum testing.
I should add there was no sign of overheating up to the point of the engine stopping.

 

[slowhoon]

Just to add more into the mix, here's another thread that I contributed to back in 2018 as I was gathering information to build a race motor:

Thread 'Weber DCOE?'

Jan 13, 2018

As I'm still sitting in Spain waiting to get my mustang back in my hands, I'm trying to plan out my build and wanting to keep my stock engine.

I know one thing for sure, I'll be saving up money to hopefully get an aluminum head from vintage in lines either for the next production or the one after (even a second hand one if possible).

As I'm researching I'm thinking about doing a side draft carb set up and was wondering if anyone has had experience dealing with them on the 200? What kind of power can I expect from a triple carb Weber DCOE set up? I'm just trying to good street able daily...

• Omoitsurugi
• Replies: 26
• Forum: 144-250 "Small Block" Six Performance

And to really throw everyone off guard, I've attached a photo of the car taken in March 2025. Yes, really, there's a 170 in there.

 

[Jmustang_65]

Are ford 200 inline 6 available in New Zealand?.... I would go with that, as it has 5 freeze plugs and 5 main caps instead of 3 on the 170.

 

[slowhoon]

Are ford 200 inline 6 available in New Zealand?.... I would go with that, as it has 5 freeze plugs and 5 main caps instead of 3 on the 170.

They are - and it's odd I seldom see them coming up for sale here.

However they are wider than the 3 bearing block where the bell housing bolts on, and the gap between the footwells in the car isn't wide enough for the 200 block to fit.
Even the rare 3 freeze plug 170 engines have the same problem (I had one for a while and sold it before I realised it probably had a 7 bearing crank).
There are other issues of course, like the car is classified as a Historic Sports Race Car so under that classification I have to run the 170. Plus I'd be up for a full set of new pistons, the correct bell housing and a new adapter plate to go between that and the gearbox.