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Hi all,
Some of you will probably have heard by now that our La Carrera Panamericana FJ split a bore about 400ks out of Mexico City.
Thanks to our Mexican support team, who really pulled a rabbit out of the hat, we got it going again and finished the event.
Now the car is back home again we want to get at it and rebuild the motor.
So that we don't make the same mistake again and have the same problem we want to use the best block we can in the rebuild.
Many people have given us advice but unfortunately most have different ideas as to which if the red/blue/black 6 cylinder blocks is the most robust.
As we don't have a lot of experience in this area I would value any input forum members might like to offer.
At present the blue XR5(?) blue seems to be the front runner.
Any help would be appreciated.
Cheers
Dave
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Hi , I think 186 was the peak of the holden 6s , I have not seen a blown up 186 , unlike 202s & 3.3s that pop conrods out the side when pressed too hard !! Mark. |
life is good in "Wine & Holden Marlborough " |
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Core shift in the bores will kill a block in must cases especially in performance applications.
The bore walls can be ultrasonically measured.
Measuring the bore walls before and after machining can help you choose the right block.
Other imperfections in the bore walls can be found with the ultrasonic gear before machining.
James |
You only have to be in front at the end of the race. |
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Dave, Whilst being no expert on the subject, I read an interesting article that covers all aspects of what's best with these motors. Here's a link to that article http://oldjohnno.id.auCheers Bob
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In my experience the best way to make an engine 'bulletproof' is to re-sleeve each of the bores.
There are different types of material used for engine sleeves, the best being chrome moly. It was relatively commonplace in drag racing during the 70s & 80s especially in F@rd Clevelands.
This might sound a bit over the top money-wise, but compared to the overall expense of building the car & transporting it to the other side of the planet, it's not a lot of cash.
In my experience 179/186 blocks are in general no stronger than 202 blocks, it's just that early HQ pistons were known for their weakness & the slightly longer stroke is more likely to cause breakage at high RPM.
Also, generally speaking, the newer the block the better. Old 60s blocks now are usually too far over-bored &/or too rusty to bother with for performance purposes.
Dr Terry |
If at first you don't succeed, just call it Version 1.0 |
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The other consideration with the block is what crank you want to run, the rear main seals changed so unless you want more machining costs pick the right block and crank combination.
Given that you are taking this to the other side of the world you probably want reliability over all out grunt, I would probably stick with a Blue motor bottom end and follow Dr Terry's advice.
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Another HQ SS |
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hi there, for me id use a black block with ported efi head. sleeve all bores and use xu1 Bathurst cam, pay lots of attention to cooling system. stable coolant temp is the go with 10deg c rise from water in to water out, or correct tuning is impossible.cheers. |
wjcera |
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Like what DR terry and JBM said. All blocks are the same as to regard to bore strength thickness from 186 to the 202. The blocks that are considered best are the so called ribed block she has ribs at the back just behind the rear of the oil filter like this comes in late red motors on. I think you must of had a pin hole in the bore not a split if they were to fix it ? if she was a split bore you would be just tossing the block away right their and then end of story. and the pin hole is causd by a bad rust problem. You have to have a good look see at the next block so pull out the welch plugs and don't bore out to 0.060 as only idiots do that to a race motor. Edited by user Sunday, 26 January 2014 7:17:39 PM(UTC)
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Blue and black 202 motors have a better crank and rods than the red. the last of the reds from about sep 1978 got the blue motor rods only.
Red heads can make more power than the blue black when modified.
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XT5 is what the blue motor is called.
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Hi all,
Thanks for your responses, suggestions and links.
I greatly appreciate the effort you all took to reply.
I'm still accumulating information so the more the better.
Just to fill you in a little on what actually happened, the car started to over heat just after the end of the last stage on day three of the event. We thought we had damaged the radiator but no evidence of external leakage. Topped up the radiator and headed for the overnight stop about 80ks away. The car run cool until about 10ks from the end when the temp shot up again. We crossed the finish line late but got there inside our allowed late running time. Our support crew sent Greg and I to have a bite to eat while they sussed out the problem. They found the sump to be full of "cappuccino" so, suspecting a blown head gasket they removed the head, only to find a 50mm long split in no1 bore.
The split ran radially around the bore from right behind the water pump at about a 30o upward angle towards the right hand side of the block.
To cut a long story short, at about 10.00 at night they rang an engine reconditioner mate of theirs back in Mexico City about 400ks behind us and arranged to get the engine to him first thing next morning. They pulled the engine out and left for Mexico City at about 3.30am and arrived there at about 7.30.
The guy was waiting for them.
They dismantled the short, the guy made a sleeve, bored the block and installed the sleeve and cleaned up the piston as best he could.
They had the short back together by 4.30 that afternoon and headed straight back to us, now about 700ks in front of them because we had trailered the car to the next overnight stop so we wouldn't end up a day behind the event.
They arrived at a workshop they had arranged through another one of their mates at about 11.30pm and worked through the night to refit the engine.
Our nominated start time for the next morning was 9.35.30am and we got the car to the start line at 9.27 thanks to the incredible efforts of our support team, both Mexicans and Aussies.
To them I owe a huge debt of gratitude for all they did to enable us to finish the event, which we did.
So there it is, definitely a split and a mammoth effort to repair it.
Cheers
Dave
P.S. We are gong back in 2015 to attend to some unfinished business with a Pom in a Jag but in the meantime, in September , as a thank you to the Mexicans, they are going to come down here and we are going to crew for them and let them run the FJ in Targa Adelaide so we need to have it properly sorted by then.
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If reliability was a very high priority item, I would have all 6 bores re-sleeved professionally. 40 thou over on a red 202 block with a dynamically balanced blue crank with blue Starfire rods. Has worked well for me. |
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Hi,Dave maybe you just got unlucky with a bad block?
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