Shimless buckets????

Final stages of my engine build and hearing scary stories of the shims getting spat out with high rpm engines.

I'm using 280 cams, raising the rev limit and looking at numbers between 800-1000bhp, are many people staying with the oem over bucket shims?? Or would you advise shimless? Thoughts would be greatly appreciated

The sort of revs you will talking of are pretty mild in the OHC engine sphere, so the shim over buckets should be fine. I think Gen 3 MR2 turbo buckets will work, with top hat shims on the valve stems I make my own silver steel top hat shims, and send them for through hardening when made, and before grinding to size, should you want to go that route. You can make them in a decent lathe with a suitable size milling cutter in the drill chuck. then part them off and harden.

I thought it was the aggressive angle on the 280 cams that can pop the shim out at the higher rpm's. I am happy to be corrected though as I was going to change over to shim-less buckets.

Do you make them in the same style as the normal buckets but one piece Chris? I can get the steel and have a decent lathe

I have shimless buckets, less pieces to go wrong.

I thought it was the aggressive angle on the 280 cams that can pop the shim out at the higher rpm's. I am happy to be corrected though as I was going to change over to shim-less buckets.

 

Do you make them in the same style as the normal buckets but one piece Chris? I can get the steel and have a decent lathe

280 degree cams are tame Very tame. Once you get well over 302 degrees you are talking a proper race cam

What I meant is I think the MR2 Turbo, Gen 3 buckets drop right in the 2JZ heads, and they are designed for shim under bucket.

Pretty sure you're right Chris. I also think either the 1zz or 2zz fit too

Friend of mine uses Yaris buckets in his 2JZ head I think, Ill have to check on that.

No need to change the buckets until 8500rpm

Thanks for all your help I've spent so much time and money shimming to get them all spot on its a shame to bin an start again if they are upto the job.

I have read that shimless buckets are lighter and overal a good weight saver I guess that with no risk of losing a shim is all positive factors

What do you envisage revving this engine to John?

What do you envisage revving this engine to John?

I believe it was 8500, I don't want everything on a knife edge like a race engine, As with most I want to keep on the reliable side

depending on what cams you have I had to go shimmless .

Brian Crower is known for making high quality camshafts that make power without breaking the bank. There is no other cam manufacturer on the market that gives you more value for your dollar, and the parts just work. We use them in our own cars and we encourage our customers to use them as well.

Giant lift profile for ultimate RPM. Full race motor running race fuel. Tuning ECU mods required. Requires kit BC0300. Shimless buckets & cylinder head clearancing required.

depending on what cams you have I had to go shimmless .

 

Brian Crower is known for making high quality camshafts that make power without breaking the bank. There is no other cam manufacturer on the market that gives you more value for your dollar, and the parts just work. We use them in our own cars and we encourage our customers to use them as well.

 

Giant lift profile for ultimate RPM. Full race motor running race fuel. Tuning ECU mods required. Requires kit BC0300. Shimless buckets & cylinder head clearancing required.

Do I need to grind cylinder head lobe access in my 2jzgte for 272 BC cams?

Duration is irrelevant, lift is the critical factor in head to lobe clearance. I'd ring them and ask, but even so I would physically measure clearance on *YOUR* head casting.

I had splashed shim at only 700bhp and a 264 cam. Rpm limiting with ignition cut Can kill anything. I went to shimless mr2 buckets and of course changed rpm limiter.

I had splashed shim at only 700bhp and a 264 cam. Rpm limiting with ignition cut Can kill anything. I went to shimless mr2 buckets and of course changed rpm limiter.

 

 

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Splashed shim?

Displaced shim?

Duration is irrelevant, lift is the critical factor in head to lobe clearance. I'd ring them and ask, but even so I would physically measure clearance on *YOUR* head casting.

What's the best spot to measure in the head to be sure they won't touch? Also dumb question but I measure this when only when everything is torqued down full then just manually spin the crank clockwise right?

You check with one cam at a time in the head, no valves or buckets and slowly tighten the caps rotating each cam and looking / feeling for contact. If no contact occurs with the cap bolts fully tightened you them measure clearance at the tightest points with feeler gauges. I wouldn't want less than fifteen thousandths of an inch absolute minimum. If contact or insufficient clearance occurs then clearance needs milling in the head casting. You need to be very careful or you will have a two or more piece cam to think of an ornamental use for.

Shimless buckers here

I like the idea of less to go wrong, it helps me sleep at night - Although the cost of the little buggers keeps me awake at night!

Displaced shim?

Shim broken and afterwards thrown around in the head

Out of curiosity , the MR2 Sw20 is shimless Bucket from factory as far as I am aware , why was the A80 not Shimless , cost, just down to old tech ? are all modern cars shimless?

Most direct acting overhead cam, and soe indirect acting use hydraulic buckets for long term quiet running and less maintenance. the shimless bucket4 pot Toyotas went that way as they turned a LOT of revs, plus there may be some assembly cost savings with them.Most race engines that haven't got pneumatic valves use shim under bucket (tiny top hat shims that are very light). Older Vauxhall 4 pots used tapered Allen screw adjustable buckets, which seemed reliable and made valve lash adjustment quick and easy. They never caught on, possibly cost or weight being the issue. What I sometimes do is buy only thick shims and surface grind down the side that sits in the tappet, or grind the valve stem tips to give correct clearance without a vast and expensive inventory of shims. You can do the same with shimless, buy only thick ones and change clearance with valve stem tip grinding. You MUST be ultra careful not to take too much off the valve tips, firstly to avoid getting through the hardening and secondly to make sure there's no interference with the retainer collets or the bucket to head.

I thought only the Beams 4 pot Toyota (similar to the MR2 engines, but Ti rods and trickery within) used shimless buckets but maybe the late 2S-GTE used them, too? I know the Beams shimless buckets fit the 2JZ lumps

The only real point in using shimless is on 2JZ's that turn huge revs, where valve train oscillation or bounce can cause the relatively heavy shims to get flicked out. Same with Ti retainers and top hats, Ti galls on steel and can cause issues, Serious race engines treat them as throw away at rebuild time..