Anyone install 1.65 ratio rockers on heads with valve skirts?
Jim,Valve skirts? You mean "oil shields"? Should not make a difference as long as your lift is not crazy. You can always test fit a rocker arm and rotate the engine over and measure the clearance.
Did you clearance the pushrod holes in the head to make sure the pushrods don't bind and bend? Stronger valve springs? ARP Big Block rocker arm studs?
OK, cool, more info which was needed. I would not use the 1.65 rockers as a means to get additional lift. The 2 Bbl heads are the low compression, small valve heads.Jim,
I have been a member here for a short time and find that you share your experience with everyone no matter how trivial it may be.
Thank you for your contributions.
I have not yet taken the plunge to purchase the rockers. Hoping that I can get input to be sure it will work.
Actually I have not even removed the valve covers but assumed that the valve springs would have what I call skirts and assumed that they would potentially be an issue if I added lift to the valves.
I have the original 2bbl heads #14 with the original cam and lifters. I am trying to avoid getting into the engine but would like to give it a little more “fun factor“.
Everything depends on your budget. A complete rebuild could cost you around $4500ish depending on options. The more you can do, the additional savings.Awesome information. I was hoping to avoid a new cam and lifters. But while I have the engine out might as well. Sounds like it would be a good idea to go ahead and pull the pistons and do a rebuild to avoid issues down the road. Will the larger valves fit in these heads or should I find some better heads?
Pontiac Jim,Everything depends on your budget. A complete rebuild could cost you around $4500ish depending on options. The more you can do, the additional savings.
You are going to get different opinions on the heads. First, any head you get/use, have it cleaned and magnafluxed for cracks. You don't want to invest a dime more should they turn out to be bad.
You already have the #14 heads - so no costs there. Buying another set of later heads with 2.11" intakes and screw-in studs will have to be added into the other costs to rebuild them. So a saving advantage with the #14 heads.
You could use your heads and install larger 2.11" intakes. Your machine shop will do this. They will have to open the throat with a cutter and then fit the valves and do a valve grind. This will give you fresh seats.
If you buy heads already having the 2.11" intakes, you will want to make sure that the valve seats are good and have not seen a couple of grindings which can sink the valves - you need a specific seat margin which your machine shop will know about.
In case #1, you will have to buy new valves. In case #2, you may be able to regrind the old valves - if they fall within spec. But, they are old.
New Ferrea stainless steel valves are about $90 a set. For $90, you get new and better valves. There are the longer RA IV valves which with matched springs, allow for a higher lift depending on how big a lift on the cam you want to go. You can also get the stock height valves as you now have, just a tad bit shorter than RA IV, but note that you will have to buy new pushrods with the longer RA IV valves. If your budget says "nope" then go with the stock length as you now have. Here is RA IV https://butlerperformance.com/i-24453184-ferrea-high-performance-stainless-steel-intake-valve-setfer-f5143-8.html?ref=category:1400522
A factory hi-po head will have the 2.11" intakes and screw-in rocker arm studs. You won't use the factory bottleneck studs for any good high lift cam - you will go with the ARP 7/16" Big Block Chevy rocker arm studs and poly locks. You unscrew your bottleneck studs from the factory hi-po heads and replace with the ARP studs - pretty simple.
With the #14 heads, you would buy the ARP screw-in studs specifically designed to replace the press-in Pontiac studs. I don't know if the rocker arm stands will need to be spot faced to get them flat prior to the machine shop cutting threads down into the stands for the screw-in studs to bolt in to. Again, fairly straight forward for a shop to do. In both cases, ARP studs. A little extra cost on the #14 heads if the rocker arm stand need to be milled flat (I have read both accounts where "no they don't" and "yes they do.") and tapping the press-in holes to accept the screw-in studs.
I would also install new exhaust valves in either head - so same costs there. The 1.66" exhaust size will work fine, or you can size up to 1.77" but will add additional costs in opening up the throats for fit.
My guess would be that either head will need new valve guides. Never knurl valve guides as this is a quick fix, but not one for long term if you plan on keeping the car. Some shops will use a cast iron valve guide to replicate the factory cast iron head and then hone to fit the valve stem. A better upgrade is the bronze valve guide. You save a few dollars on the cast guide, but both will require insertion & sizing - so no savings on installation as costs will apply the same to either heads.
Valve springs will be selected to match the cam lift.
Valve Seals. The Ferrea valves do not have a second ring/groove for factory type O-ring seals. So you will need to use a seal that fits on the valve guide which means the valve guide will have to be machined to accept these. Viton valve seals work best. Not a big operation. This generally will also mill down the guide and provide more clearance between the bottom of the valve spring retainer and top of the valve guide - so that could be a plus with bigger lift cams. Butler explains and provides examples: https://butlerperformance.com/n-13487-pontiac-valve-stem-sealing.html
You will want a 3-angle valve job. Porting/clean up of the ports would be extra. I did my own, but have the tools and experience in doing them. Now I don't know how good a job I do as i have never flowed a set. I may have made them worse! LOL My 7K3 heads ran me about $1200 to have rebuilt with me doing the porting/bowl work. Here is a set ready to go out the door and flowed, and not too bad a price all considered: Nitemare Performance | Custom-Ported Pontiac Cylinder Heads
Some will say you need to add hardened seats. Note on the Nitmare heads, no hardened seats are added. I questioned the owner about this and he said he did not install hardened seats on any of his heads as the Pontiac heads were not designed for them. Instead, he uses a gas additive, Driven, that helps to lubricate the valves/valve seats and provide a slight more octane. Said he has never had a problem.
So you have options, but in the long run, I think there will be little difference in savings in buying another set of heads and rebuilding them, using our #14 heads and rebuilding them, or save the grief & time and purchase a ready to bolt on set of heads for a little more $.
Don't select pistons until you know what your actual head chamber cc's are. You will match your piston dish/valve relief cc's to the head cc's to arrive at a streetable compression ratio of what I feel is 9.0-9.3 for iron heads (unless you live at a high altitude and can go higher compressions). This will typically mean a custom forged piston. You also want a forged connecting rod, if nothing more than the lesser expensive forged I-beam. You will also have to balance the engine.
So you want to do the research and have an idea of what you want out of the car and for what purpose you will be mostly driving it as - street crusier, local around town, highway, street/strip, or other. You then have to take into account the HP/TQ you may be adding to the drivetrain and what upgrades will be required. Many forget about this, so it can cost more $$$ to be able to handle any big HP/TQ increases.
Late to the party, but....Pontiac Jim,
Thanks for the information. I will be reaching out to Nitemare next week. #16 heads and RA exhaust with 2 1/2” pipes. I will wait till I get bottom end to the machine shop to decide what I will do there.