Valve springs, pushrods and trunion upgrade advice.

[Fu Manchu]

I’m starting to put thoughts toward those components in the Cross8.

Not sure if replacing those for peace of mind is the way to go. The motor will be getting a refresh later but not straight away.

So I’m guessing without a big cam, the dual valve springs are woftam. So what’s a good brand to look for in a single valve spring?
Crow, VCM I’m going to guess are good enough?
Is there a type in particular worth looking for?

Pushrods, I’ll pull them out to inspect them, but what hardened or heavy duty ones are worth looking at?

I’ve seen two types of trunion upgrade kits. One with the brass bush, and one that keeps the needle bearings but securely. That’s the one I’m probably best looking at?

I’ve only driven this twice. It‘s internals are completely unknown.

It will be a daily and do a few beaches, so some revs involved with the soft sand. Stock does it pretty well from what I’ve seen but I’m a bit nervous about the rockers.

 

[losh1971]

Forget Crow springs they snap more often than other brands. Trunnion bush kit try Michigan Motorsport. I think that's where I got mine cheaper than anywhere locally and that included freight to Tas, taxes and exchange rate.

 

[losh1971]

From my searching these are the cheapest for a quality PAC spring and will suit a mild cam or stock cam.

https://www.revhigh.com.au/product-...z-ve-vf-ls1-ls2-ls3-l98-l77-v8-5-7l-6-0l-6-2l

 

[Ginger Beer]

Stock cam only needs stock valve springs, same same for pushrods, unless your running boost or reving its tits off

I'm running trunnion bushings which are running fine

Only reason was the original trunnion bearings had some side to side play and my engine builder recommended the bushings

If nothing is currently broken I would wait until you changed your cam, then get springs and pushrods to suit

And while your in there look at trunnions, as well as a high volume oil pump, water pump, new timing chain, underdrive balancer kit etc etc......

All cheap '"while were in there" preventative maintenance parts that otherwise would be a PITA to change

 

[Fu Manchu]

Well a lot of that isn’t too hard. Two years of cleaning and fixing so far so time is not of the essence.

I will still be pulling the springs etc before I start this. Just to inspect them. Water pump will be done. New cam sensor, oil pressure sensor, radiator, oil cooler, ps rack, steering cooler, valley cover seal, leads, pulleys, belts, ps pump, coolant sensor, injectors. So lots to come.

It’s just these few things I’m not sure on. 300000 on the motor. Well serviced.

 

[losh1971]

It takes a garage about 7-8hrs to do springs and trunnion bushes. If you can do them yourself you will save a decent chunk of coin.

 

[losh1971]

And while your in there look at trunnions, as well as a high volume oil pump, water pump, new timing chain, underdrive balancer kit etc etc......

Why would you need a different balancer than a just stock replacement in PB? I agree about changing it as the PB is a better unit than the factory original. Looking at those underdrive ones and the price triples IIRC.

Edit, not quite triple but $293 as apposed to $118.

 

[Ginger Beer]

Why would you need a different balancer than a just stock replacement in PB? I agree about changing it as the PB is a better unit than the factory original. Looking at those underdrive ones and the price triples IIRC.

Need.....inspect the standard one, mine had to much run out, and, after removing it for inspection, was being spun off due to the PD blower , so we replaced it with a standard size Powerbond (standard size because PD supercharger) and pinned it to the crank

As for price, it's only a few hundred extra for a much better unit

So, if NA, 25% underdriven Powerbond would be my choice if I needed to pull the old OEM one, 25% underdriven will free up a few ponies

And if PD boosted, pin that sucker down

 

[losh1971]

Need.....inspect the standard one, mine had to much run out, and, after removing it for inspection, was being spun off due to the PD blower , so we replaced it with a standard size Powerbond (standard size because PD supercharger) and pinned it to the crank

As for price, it's only a few hundred extra for a much better unit

So, if NA, 25% underdriven Powerbond would be my choice if I needed to pull the old OEM one, 25% underdriven will free up a few ponies

And if PD boosted, pin that sucker down

I already bought a standard PB, wish someone had mentioned that I could save some HP if I went underdrive.

I have been told the factory balancer is a fairly average unit and tend to cause problems. No idea what I currently have on mine but given I'm just over 210k I doubt it's original as my AC is not playing up, like what happens when the factory unit starts to give out..

I have a newy in the shed waiting to go on when I can be bothered spending the coin to have it done.

 

[losh1971]

So a 25 underdrive will save about 8-9kw. Don't think I will go to the expense of buying an underdrive for those savings. On my bus it would be about 3.5% increase in power. If I was competing it would be worth it as I know about saving every bit of HP you can when you race. I removed every non-essential thing driven by my engine on my bike and drilled everything possible to save driven weight to get the most I could from it. But for a DD I don't know if it's worth it?