I'm needing some advice, Picked up a set of 74" jugs and heads, jugs are scored pretty good and heads need valve job. I'd like to give the engine a bit more oomph. what type of pistons should I run, flat top high comp?? and should I have the jugs bored before ordering pistons (sizing) that makes sense to me, although I have no brain sometimes. As for the heads, what can you recommend for a complete valve job, types etc.... and i've heard of a five angle valve job, what the hell does that mean??

thanx for the input

Jeff

Note : i'm in Florida and it does get warm, if that matters

 

I like KB pistons(great product for the price), but you run them at half the clearance of standard pistons so make sure whoever is boring them knows that. clearance is .0015" instead of .003". they make them in 9.5:1 compression, your machinist should be able to tell you exactly how much oversize pistons to buy, so have him look/bore the cyls before you buy pistons. He can then finish hone them to proper clearance once you get the pistons.

as for the heads, rowe makes good reliable valves and guides. and a standard 3 angle valve job is fine for a shovel. I would replace all valves and guides, as long as you are there.

I have been running this setup in my 1980 FXEF with an andrews a/b grind cam, and it has been very reliable and the power is pretty good as well. I live in Dallas, where temps hit 90-100 4-6 months out of the year. (oil cooler is a life saver here!)

 

I bought my first Shovel in '78 and the above advice sounds good.

 

Thanx for the input guys

Jeff

 

In my shovelhead days, it was common for us to install bronze intake valve guides with valve stem seals installed. Cast iron exhaust valve guides without valve guide seals. The thinking was because of exhaust valves getting so hot, it was a good idea for a little oil to be lubricating the valve stem.

 

If you are going to go through all the trouble or replacing valves etc, as well as boring out the jugs and putting in high compression pistons, maybe porting and polishing is a good next step to take as well (depending on your wallet and/or expertise I guess)

Tuk

 

Very much agree, if horsepower is your goal a good set of ported heads will definately benefit the shovel head motor.

 

Thanx guys, In reference to the valve job, should I run seals or not, i'm a little confused on the reply from Harleyphoenix, all sounds Ok so far as well as porting heads.... I had that in mind.

 

run the valve seals(cast or bronze),go with about 10.0-1,on the shovels,we use andrews #6 cam,dual plug the heads.as far as porting goes,with the inconcistency of machining,we have to see the shovel heads first before we will do any porting(some heads its not cost effective,cheaper to get aftermarket heads)
kirby
facebook: kirby apathy

 

Prodrag is right. The best port and polish job and valve cutting, with dual plugs will not even get near a set of off the shelf S$S heads, or some of the other aftermarket performance parts suppiers, and the cost is about the same. One other thing. The person doing the work had better know what they are doing. Once you start taking the material off, it can't go back on. Does your head man have a flow bench? Just some things to consider.........