Engine rebuild - parts advice?

[modnrod]

Gday all.
My engine is out, the trans is off to one side (*sigh*), and what do I find? Yep, mains are just through to the copper, the rod bearings have a "hot-spot" smack in the centre, and although on a quick inspection the crank journals look really nice, I haven't mic'd them or checked runout/side clearance yet. I bought my bike as an import from Japan, I knew it had been raced (custom holes for frame braces, wiring connectors on MAP and coil wiring), but didn't concern me, I'd been looking for a good '80s V4 for ages, and this one is nice. I raced it too, but on the very 1st run it skipped while in 2nd........after another sigh, I just rode it around for a bit (it now has 18000km from new - 1987), raced it when I just had too (but missed 2nd gear), and now here we are. It's obviously been buzzed a bit high looking at the mains (I did it once with a false neutral, but only once), and has had a gutful of NO2 (1/16NPT plugs on the inside of the mainfold), so the rings are probably gone too, but haven't got in there yet. Just the usual stuff.
It's funny I reckon the best result from the bike was one of the slowest times.........60ft 1.706, ET 11.78, speed 118.......but that was going 1st - 3rd and 3rd - 5th, coz 4th jumps too (another *sigh*).

Anyway, does anyone have any recommendations as to a particular brand or type of mains and rod bearings, same for rings? Are there any other options besides genuine? The mains have F-780-NG stamped on them, is that a genuine stamp mark, or aftermarket from Federal Mogul? What does everyone use for their rebuild stuff? I figure while it's in bits anyway, I'd rather do it all once. Hopefully it will get me through a few years of having fun.

When it's back together, it will have an air-shifter with ignition kill, back-cuts, slightly lower compression ratio than stock (bottle).......and a REV LIMITER!!!!

All advice from those who've been there / done that warmly received.

Oh yeah, one more thing. What brand of valves does everyone use for their head work? Flat "Milodon" style inlets and high-tulip EVL exhausts? 1mm bigger than stock Suzuki stuff?
Thanks guys.
Dave

 

[veebooster]

You have to talk to Sean Morley. He's done just about everything that can be done to Vmax engines.

Dale #2592

 

[SpecOps13]

Ditto, Sean is the #1 Guru of VMax Engines...

 

[one2dmax]

Stock bearings (which there are a number of them to pick from based on your codes). The stock pistons are pretty odd for ring sizes so stock rings too. I have most of that stuff on hand. We can of course get a variety of aftermarket pistons for more or less compression. Bore your cylinders for larger displacement and many other options. Of course many people have us do some transmission work including overdrive options.

Email me for a spreadsheet showing costs and many (though not all) options.

Sean

 

[modnrod]

Thanks Sean.
I'll re-check in a few days the colour codes (I work away), they're on the inside of the bearing centre, right? I'm not interested in big-bore's really, a 40hp shot properly tuned does the same, and I got a box of the stuff in the shed.
I'll send off an email about the bits.

Do you get into the head/valves at all? Just looking inside and comparing it to other old-girl 4valve stuff (GSX, ZX, etc), I reckon there's a bit to be had in there, just want to keep it all under 9-ish with std cams (do you run the usual 104/110 on these motors?).

Thanks for the responses.

 

[one2dmax]

The heads can have many things done to them depending on how much you want to spend. Most of the engines we build run 93 or less ocatane! You can get super high comp pistons if you want that will require race fuel but that of course makes them impractical for street driving.

Sean

 

[modnrod]

I do my own head work, so it's just a matter of high flow valves. I haven't seen Vmax specific ones yet, but haven't really looked hard yet. I don't mind spending $300 on valves, then with a good 5-angle blended seat I'm usually 20% up and haven't touched the port yet.
I normally try (for a streeter anyway) to get the best flow head under 10rpm, then use std cams with lca's to build the bottom/mid.
Just not sure where to try for the valves, or even just get GSX inlets (+1mm, stem length close to work with).