Page 1 of 1
solid lifters clearance
Posted: Fri Jan 05, 2018 7:04 pm
by Pitschi
Hi there,
running solid lifters (Chevy) and adj. steel rockerarms (Volvo) on the RV8 (not built by myself) and after approx. 3000 miles it sounds a bit noisier now. Can anybody tell me how much clearance for new adjustment? 25 thou? #
Thanks in advance
Cheers
Pitschi
Re: solid lifters clearance
Posted: Fri Jan 05, 2018 7:16 pm
by Coops
mines about 24thou i think.
12 cold
all depends on your cam recommendations?
Re: solid lifters clearance
Posted: Fri Jan 05, 2018 7:23 pm
by Pitschi
Problem is, that I don't know what cam was used
Just know, and I hope it is true, that a Holbay cam was used.
When I refer what cams where possible, I found:
Holbay 111R 39/73/73/39 292° .429" Hyd. Fast Road The Tornado
Holbay 125LHC 40/84/89/45 304/314° .520"/.541" Hyd. Competition Designed for maximum performance within rpm limits of hyd. lifters.
Holbay K3A 58/88/74/50 326/304° .432" Solid Competition High torque design.
Holbay 751R 63/95/95/63 338° .451 " Solid Competition Maximum bhp at higher rpm.
When the spcification is true, only two are possible.
Re: solid lifters clearance
Posted: Fri Jan 05, 2018 7:25 pm
by Coops
solid lifter cams are always a bit noisier than hydraulic ive been told
Re: solid lifters clearance
Posted: Fri Jan 05, 2018 7:29 pm
by Pitschi
Just want to check, if everything is okay or need an adjustment, just for sure.
Re: solid lifters clearance
Posted: Sat Jan 06, 2018 5:22 am
by strokerengine
Solid lifter clearance various with cam profiles.
Some are as loose as .028" while others tighter at .016.
Living in the US I use the old imperial system, so inches.
An engine grows when it gets hot.
I found iron blocks with aluminum heads grow about .006".
Just today I checked a motor hot that I had set the solid rollers to .010" and it was right around .015 to .017 hot, which is right where I wanted it.
Not so sure how much iron heads grow, do do a lot of them, but I'd guess .003" to .004".
You can cheat a bit and run a cam tighter than specified, it will pick up higher RPM due to increasing the duration, but I'd only recommend do that for racing.
Re: solid lifters clearance
Posted: Sat Jan 06, 2018 1:03 pm
by Darkspeed
Clearances on the Kent M248 and M253 are 0.55 and 0.66 respectively (mm) so .025" should be a reasonable assumption
Re: solid lifters clearance
Posted: Sat Jan 06, 2018 1:29 pm
by Pitschi
I was thinking in mm. 0.25 mm aka 10 thou ""
25 thou " is a huge 0.635 mm.
Confused now
Re: solid lifters clearance
Posted: Mon Jan 08, 2018 10:08 am
by Pitschi
I'll try 25 thou".
Re: solid lifters clearance
Posted: Wed Jan 10, 2018 10:09 pm
by stevieturbo
And make sure if it's a hot tolerance....it's checked hot !
It's surprising how much the engine expands from cold and the clearances can increase....on an all alloy engine.
Apparently on those with iron parts, it can go the other way !
On my LS, the cam setup I have, I set tight, no lash when cold...and when it's warmed up it ends up around 10-12 thou.