Solid lifters in Stock
 

When the rule was changed to allow solid lifters in Stock eliminator engines that were previously hydraulic equipped, did racers change cams or just install solid lifters ? What typically would they set valve lash at ? Not looking for top secret info just a general idea.
I have seen solid cams run in engines (not NHRA stockers) with hydraulic lifters that seemed to work "ok" but never the reverse procedure,

Re: Solid lifters in Stock
 

Myself, I have just switched lifters. BUT, the pattern on the cam had to appear normal, I lubed the lifters just like installing a new cam. Put break in oil in the pan. Set lash and ran it for a Half hour at 2500. With a hydraulic cam there are no clearance ramps ground into it so I run lash tighter than usual. (under .010)

Re: Solid lifters in Stock
 

I installed solid lifters on hydraulic cam and was told by a well known cam grinder to set lash at .004 - works fine!

Re: Solid lifters in Stock
 

has anyone noticed a hp increase or a better et?

Re: Solid lifters in Stock
 

-With solids, you loose lift at the valve due to the lash under running conditions.

-With true hydraulics, the theoretical lash is '0'. In reality, there is some compression of the retained oil in the lifter. How much? .004? .006? More? less?

And since the lift is checked at '0' lash.....;) -Al

Re: Solid lifters in Stock
 

Going from non shimmed Hydraulic Roller Lifters to solid roller lifters. What would you expect to see as far as performance increase?

Re: Solid lifters in Stock
 

The way I see it...
Solid Lifters allowed an engine to spin tighter with the same Spring.

Over the years (decades) Hydraulics improved with Short Travel Lifters and other modifications to get them to behave more like a Solid Lifter.

Couple questions.
Are Solid Lifters Lighter than Hydraulics?

Do solids allow better ramp rates and duration?

Is there any improvement to valvetrain control?

Re: Solid lifters in Stock
 

Minus 4 thou lift not a big issue to me .Probably lose that much on the other side with hydraulics.
Last year, guys were talking .010.
Any more real world, hands on reports about lash from last season?

Re: Solid lifters in Stock
 

I am in the process of switching from hydraulics to solids on the same cam (originally ground by crane who was of little help to me) (maybe I talked to the wrong guy). Called Bullet, they were very very helpful and instructed me to swap to an "EDM" lifter @ .008 hot. I'm going to tighten the lash from there on the dyno to see if there's any + or - results. I hope there is a peformance improvement for me with lifters, pushrods, rockers and properly setup springs.

Re: Solid lifters in Stock
 

Treating your cam , Nitride or Cryo is worth looking into.

Re: Solid lifters in Stock
 

I worked with a guy some time back who was our shop foreman. He was a Mopar wedge guy, and he knew Torqueflites inside and out. He was a self taught rocket scientist. He experienced a tendency toward lifter pump up on one of his rather radical streeters, he attributed it to not so much as valve float over the nose of the cam, but due to the long duration cam he had, the exhaust valves had trouble closing quick enough, and the lifters would tend to pump up. He got a set of solid lifters,16 adjustable push rods, and dropped them in on the hydraulic cam. He adjusted valves around .008" on both valves, then buttoned it up and went for a ride(ha,ha).The car liked it. It had more RPM in all three gears, it ran smooth at a steady speed, seemed like a win/win. He said that when he got off the freeway after a run of a few miles or so with a fully warmed up engine, it would steadily start idling worse and worse, and one time it stalled in traffic at the bottom of the offramp. Attempting to restart the engine, it cranked like it was low on compression (which it was).After a bit, it restarted, and in regular traffic, it seemed OK. What was happening was that the cylinder head temperature climbed at a hot idle, the valve stems and valve train components expanded due to the heat, and it took up the valve lash to the point where the exhaust valves weren't closing since the lash disappeared. After it returned to ambient temperatures, lash reappeared, the engine ran fine. We don't heat soak a stocker motor like that, so .008" or so lash wouldn't do this, but it might be a thing to consider. Another thing--a hydraulic lifter with a lot of spring pressure running at 6000+ rpm, would it be possible for the lifter height to decrease, allowing the maximum lift at the finish line to be less than the lift at a lower RPM? Is it possible for lash to open up at RPM like that due to the lifter starting to possibly retract the plunger?There's no way to adequately measure this while the engine is running, but the non-collapsible lifter might result in a little more lift at RPM's than we had with hydraulics. Just a speculation.

Re: Solid lifters in Stock
 

A very common problem on small air cooled engines with solid lifters. They run fine cold but start running bad and stall and won’t restart. Not enough valve lash on the exhaust side. It quickly gets worse when the valve is not able to touch the seat and shed some heat. Onan old style flathead opposite opposed twins did it all the time. Lash spec was .013” on exhaust side. Valve face wears and lash gets tighter. Eventually the hot engine runs bad/no restart scenario. Drives you crazy until you figure it out! One of many odd scenarios heat related I’ve dealt with.

Re: Solid lifters in Stock
 

My new solids are a lot lighter.

Re: Solid lifters in Stock
 

When did this rule change happen?

Re: Solid lifters in Stock
 

Interesting.
Kind of hard to explain motorcycles though.
Many were routinely set up with 2- 3 thou. lash with adjusters or shimmed valve caps on the DOHC's.. They'll run fine, hot or cold , until all the lash goes away and need to be re-shimmed. When they get quiet, ..time for some maintenance.

Re: Solid lifters in Stock
 

2018, I believe.

Re: Solid lifters in Stock
 

Mark, newer Onan V twins(air cooled) engines are built by Subaru-Robin from what I know...…..They are 60 degree overhead valve engines used in 5.5 and 7 kw RV generators. Valve lash spec is .002-.003...

They usually get loose on the lash and not tight. They routinely fail from heat working on the valves, springs, guides and eventually the guides get loose in the head. Real bad problem on those. I replace heads on them all the time...….The hotter they run the quicker and more likely the guide problem will happen.....And owners that don't change the oil often enough. 2 quarts is all they hold.

Re: Solid lifters in Stock
 

I ran my 327/275 stocker engine with plugged hydraulics at .005 lash cold. It did not like any tighter.

Re: Solid lifters in Stock
 

The ramps on camshafts on hydraulic and solid cams are designed differently for many reasons.

Due to the various ramp and lobe designs in Stock Eliminator such as dwell and non-dwell lobes, when you plan to switch from hydraulic to solid, the best is to talk to the camshaft designer at the camshaft company; not the salesperson.

If you are building a new engine, just have a new camshaft made for use with solid lifters. It will have the proper area under the curve and also, with the right lobe, you can create lofting that will provide the engine with more lift than what the actual cam was physically designed with.

Yes, due to the dynamics of a solid lifter, they tend to make more power and RPM quicker when compared to a normal hydraulic lifter only if the valvetrain geometry has been optimized. When I say normal hydraulic I am not talking about a restricted travel or blocked hydraulic lifter.
Also, a solid lifter will be lighter than a hydraulic counterpart. I always recommend EDM drilled solid lifters that are DLC coated, installed with the proper lifter bore clearance.

Many years ago during a conversation with Don Tweles at General Kinetics, he shared that his dwell lobes could be run 0.006 ~ 0.010 with solid lifters.

Re: Solid lifters in Stock
 

Thank You to everybody who replied since I revived this thread. I'm going to give it a try. I've got to do something to find some ET. Hopefully this, a 200 transmission and a couple other things will help get me going In the right direction.

Re: Solid lifters in Stock
 

Thank you,