[Eric_Oz_S2]

I'm going to replace the stock rods with forged ones. There are quite a few options including pauter, carrillo and wossner. They all seem to be around the $900 mark. I have been told H beam like the carrillo or wossner are better. Is there really any difference?

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[flash]

ruh roh - did we bend something?



the general consensus amongst engine builders is that carrilo is the bang zoom of rods, regardless of engine.

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[Eric_Oz_S2]

No bending yet. This is with the aim of raising the rev limit. Currently running conservative 6600rpm cutout

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[flash]

ah - well, while high rpm rod stretching is an issue, especially on the 1R rods, if you are running a 968 head, unlike normally aspirated, under boost, your valve train and chamber design will be as much of a limiting factor as the rods.



swapping out rods is expensive if you plan to do it right. it requires a full rebalance of the engine, which of course means you have the thing out and are rebuilding it anyway. be sure you are ready to do that. i just went through it and dropped a cool $20k in the process. glad i did, but it sure hurt the wallet.

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[Eric_Oz_S2]

No plan to re-balance. Not sure why you would 'really' need to do that. Rods and pistons will be balanced if necessary. Crankshaft will stay as is. New piston rings, will check head to see if valve seats need machining. New valve guides if required. New valve seals. Debating whether to replace valve springs. Won't be anything like 20k. If I was spending that sort of money I would be getting Michael Mount to build a 400hp NA engine for me.

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[flash]

nope - i have never seen a set of rods balanced out of the box, because the pistons are not balanced to match. you have to do everything all together. i would not swap rods like that without balance. you could easily end up ruining the whole mess.



the last i heard, even michael has never never gotten that out of an NA. the only one in know of that he got even close with was an ITB motor, and that one was $40k and still fell short by a long way (325 i think). pete has one that does 300, but that one cost over $20k.

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[Cloud9...68]

I went somewhere in between. New true 11.1:1 compression Wossner pistons, with rings fit to match the measurements of the bores, Pauter "lightweight" forged rods (per Mike Lindsey's recommendation), everything balanced as a unit (crank, rods, pistons with rings, flywheel, and clutch), cross-drilled and polished crank, refreshed head with new valve guides, and seats re-ground (although the guy who did the head said the seats were the hardest he'd ever seen, and they and the valves showed no measurable wear), and of course new valve seals, but no new valve springs, head or crank cradle studs. Of course I replaced the rod and main bearings (and the balance shaft bushings), but I didn't know about the recommendation to use different clearance bearings on different rod journals. I also didn't have the engine blueprinted, although I had the deck height checked - it was perfect - and the block surface checked for flatness (also perfect). On a whim (and a recommendation from Craig Woodman), I also had the piston tops, combustion chambers, valve seat faces, exhaust ports, and exhaust manifold (stock) ceramic coated. It also has an insulated intake manifold gasket from RS Barn, and a crank scraper, also from RS Barn. It also has the Lindsey Racing flap-style oil pan baffle door, and I had the oil pick-up tube reinforced. I replaced all the seals and o-rings, of course, and the variocam chain and pads, but didn't replace any sensors, or lifters. The rod bearing nuts are new, but not the head nuts. I pulled and replaced the engine (with the help of a friend), and did all the disassembly and assembly myself, so the total came to just under $6K. I did everything according to the manual, but not knowing any hard-won engine builder "tricks", I'm sure I left several horsepower on the table, but that's a compromise I can live with (not like I have any choice, as having a builder do everything was WAY out of my budget).

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[Eric_Oz_S2]

Thanks for the info. I was also going to get the piston crowns ceramic coated, but not the valves. Where did you get the Wossner pistons from, and are they truly compatible with the Alusil bores? I presume the pistons were around $1k for the set?

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[Cloud9...68]

I got the pistons and rods from Lindsey Racing, although I later found out that the pistons at least were sourced through Racers Edge, so you might want to check with them (Karl Poeltl, specifically). And yes, they were right at $1K. I hadn't thought about whether the pistons/rings were compatible with the alusil bores, but assumed that since Lindsey and Racers Edge work on these cars for a living, they must be compatible. In all honesty, that's how I approached a lot of aspects of this build - having no experience myself, I leaned heavily on those who work on these cars every day, such as Lindsey, RE, and especially Pete at RS Barn, who's been extremely helpful throughout.

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[taporite6]

Iam in the process of rebuilding my engine...Do you recomend knife edging

Iam also resleeving my cylinder bigger pistons new rods and cam

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[flash]

most of the builders do not recommend knife-edging this crank. first, the balance between piston/rod weight and counter weight will be off. there has been talk about the crank twisting when it gets too light, as well as the main bearings having problems. i have no idea how light "too light" is, and i can't find any documentation of the failures, but i've heard enough complaining about it to leave it alone.



what kind of sleeves and how big oversize?



i ask because dry sleeves do NOT seem to work in this engine. everyone i know so far who has tried them has had them fail.



what kind of pistons?



i contemplated going bigger on the engine, but there was a real limit on boring due to the water jackets and what it would do to the cooling capacity. then there was the whole "alusil" issue. so, i considered sleeving, but found out about the dry sleeve problem. then i considered wet sleeves, but being boosted and wanting high revs, the manufacturer of the sleeves cautioned me against it.



complicated issue for sure.



i'm also curious what rods you plan to use. i went with the carrilo, as i wanted a very stiff rod. the factory rods flexed too much for what i wanted to do.

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[Cloud9...68]

While I can't speak for all engine builders, I can second Flash's input regarding lightening the crank - specifically, Karl Poeltl of Racers Edge emphatically told me NOT to lighten the crank, due to the inherent imbalances (from multiple sources) of such a large inline 4. Just for kicks, I went ahead and weighed my crank - it's a whopping 59 pounds! At least it sits down low...

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[flash]

yup - it seems that the pulse of the large cylinders is a real problem. going bigger would create an even bigger problem. this is why balancing is so important on these engines. change anything in there and the balance goes off. if you don't do things to correct that, the engine will tear itself apart.

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[taporite6]

Thanks will let mechanic know tomorrow he says cylinder has to be resleeved ...As to pistons i was going with Wooser but i could just resleeve it and reuse the pistons i have also the rods and save my self 3 grand

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[flash]

not all sleeves can be used with all pistons. additionally only certain pistons and rings can be used with our block.



i just went through this. it was a real pain working out what i could do, and still use the porsche pistons.



in the end it cost me $20k to get the motor done.

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[taporite6]

This all started with a bad water pump Domino principle....one thing leads to another......I called J&E and they recomended Wooster

the resleeving alone is $2500 what did you end up doing

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[flash]

i bored it out and went 1 over size at 104.5 using porsche pistons



dry sleeves don't work in our block, and darton was not confident that the wet sleeves combined with the open deck design was going to work for me, given what i wanted to do in the way of boost and rpm. there is somebody running dartons right now though, and so far so good.

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[taporite6]

thanks for the information will let you know how it all goes

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[flash]

one of these days you'll make it back down to an event

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[taporite6]

the bow on my top broke on the drivers side and have not found a used part it seems i have to buy it from sunset

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