These cores have fuel pump lobes on them and can eather be ground , or not depending on the aplacation , these is no cost involved in that I eather grind the lobe off , or grind it in to a fuel pump lobe, this UGL fuel pump lobe also gives me the ability to grind more aggressive or less aggressive lobes to be in conjunction with some of the new lift pumps available.
For towing I look first at the charger or Chargers and then select the proper exhaust lobe , and then choose the corresponding Lobe separation angle .
For strict towing use I would recommend a regrind with smaller exhaust events , and the biggest intake lobe possible .
The intake lobe is the key to moving air thru the engine , and the only limit is the fitment in the engine , and the Valve spring .
The dual springs that I use in my performance application are chosen because they will cover a lot of lift , and they remain consistent thru the range of motion during the opening and closing of the valve
I have spent a great deal of time on the Sprintron with the Cummins 24valve / CR , and the main problem with the link-Bridge system like employed on the Cummins 24 valve is constants of valve spring pressure .
I tested the available springs on the market , and while they might have the same pressure at installed height. The single springs combination showed a fatal flaw , in that they were all over the map through the pressure values over the lift range .
The ovulated wire single spring has advantages , particularly on two valve applications in that this spring will fit in tight spaces . But the single spring , can not even come close to a dual spring system , just a given fact .
The only other advantage is its considerable less expensive , less then half. There are only a few manufactures in the world that wind wire in to springs . We all as Custom cam grinders draw on the same resources , from the smallest to the largest as in large cam grinders like Bullet ,Crane , or Comp cams draw on these same spring manufactures
The fatal flaw of the single spring in link-Bridge application in high performance uses , is that when one spring has more or less pressure during the cycle , the spring with less pressure lifts farther , this first rises concern for valve clearance , and the link-bridge becomes less stable , and leads to the possibility of pitching the bridge.
I can provide single ovulated wire springs for the same spring winders thou a different wholesaler for around $100.00 and still make money , I could not in good concisen do that . I started grinding cams and doing R&D on the diesel valve trains to provide the best , not the most marketable. [/B]
When I first started to provide springs the going rate of a set of 24 springs was $500 to $900 for a set of springs, that I could buy in large lots for well under a $100 a set. I set my sights on providing the very best , possible , a dual spring that required a custom retainer. I started using a titanium retainer in that it was only slightly more expensive then a heat treated chrome molly piece .
These is a lot of smoke a misinformation on this and other sites by people that were in dippers when I first started working on high performance engine design. Judge for your self .