Thanks for all the information and ideas. I'll try to describe my thought process and where I'm at with the engine side of the project.
I don't have particularly deep pockets, so I have to be careful where I spend my money. Wherever I spend money, it has to "count". That means that I don't want too much custom work being done if there are factory parts that will get the job done. For that reason, I don't want to get involved with shortening of valves, re-cutting keeper grooves, etc.
I like the idea of 7mm valves, but it doesn't look like there are any factory VW valves that would be a direct drop-in. For that reason, I am most likely going to run the stock 8mm valves, buy a fresh set of single springs, and a fresh set of lifters. I am going to keep it hydraulic for the sake of simplicity. I read up on someone else (Saurkraut maybe?) converting a hydraulic head to mechanical, but I don't think I want to get into that whole affair.
The head has already had some light porting done to clean up the bowls. I'm not planning to do any more porting. It's going to get a valve job, new guides and seals, and the aforementioned new springs and lifters.
I realize that the 1.5/1.9 combo is unconventional. I believe it will be a good setup for an LSR attempt. The head should flow better than any of the factory 1.5 or 1.6 heads (bigger valves). The pre-chambers are larger on the 1.9, and should yield a static CR of somewhere in the 17.5:1 range. Starting may be a challenge, but I have to believe that it will be capable of starting for my needs. The number of "wacky" engine combos used in LSR racing is mind-boggling. The shop that is doing my head work recently cut a small-block Chevy in half to make a V-4, which is running Subaru cylinder heads with belt-driven overhead cams for a different class at Bonneville. That is just one example of the type of creative engine combos that are used.
This will be a race-only engine. While I don't have the money to rebuild a 1.6 head at this time, I do have a 1.6 head that could be pressed into service if the 1.9 just won't work. I'm pretty optimistic that the 1.9 will work, though, and will get some dyno time before the LSR attempt is made.
The lack of static CR will be made up for with plenty of boost. Giles will be doing the pump work, I have total confidence in his abilities. It will have a water-to-air intercooler, running chilled water from an insulated tank. A big thermostatically controlled oil cooler is also part of the plan.
The current record in this class is 106 mph over a flying mile at Bonneville. While this might not sound like a big mountain to climb, the current and past record holders in this class are big names in the LSR world. The #2111 VW Caddy that formerly held the record will be on the verge of 200 mph this year, with a turbo VR6 engine and a major-league effort. The current recordholder also holds records in several Diesel Streamliner and other classes. These guys are serious heavy-hitters. Everyone assures me that it's not as easy as it looks. There are a ton of details to consider throughout the entire vehicle. Everything has to work well together in order to put your name in the record books.
There are several concurrent paths going on with this vehicle, in addition to the engine work. The roll cage, safety equipment, body work, and suspension/steering/stopping are all subject to the same level of consideration and scrutiny.
I really appreciate the input from this forum, especially with respect to the engine configuration. I have learned a lot already, and will continue to learn as much as possible. Not a day goes by that I don't think about some of the details of this project, with a goal of running at Speed Week 2013.
Steve.
Topic: AAZ valves, springs, and lifters for performance build. (Read 15650 times)
