DRD heads any experience?

[woodsbuggy1]

I am looking at purchasing a set of DRD L5 turbo heads for my 1915 turbo.
Looking for feedback or other info from actual customers.
Thanks
Kenric

[Chip Birks]

I run his L7T heads. They work just fine. Next time i'll probably just do Super Pros though. CB is much more customer oriented.

[volksbugly]

I have the DRD L5 Turbo CNC heads. They are exceptional quality. My motor is built but not installed yet...
here are some photos of my heads.

https://picasaweb.google.com/1078300117 ... directlink

[Steve Arndt]

I run DRD hand ported "L5" from 2005 year when they were hand ported. 044 castings. Also with an infinite angle radius valve job to help combat reverse flow reversion (part of the squishy engine methodology).

[woodsbuggy1]

Thanks for the input, how long did it take to get your DRD heads?

[volksbugly]

It took me about 1 month to get mine.

[Steve Arndt]

It took over a year to get mine but worth the wait. John doesn't bill your credit card until they ship so no worries there. My wait was because I wanted bare castings from CB in 40x35 then have them machined. That took a delay because CB doesn't reorder many 044 40x35s. Those are usually based off the better cooling 043 or revmaster castings.

My DRDs are ancient and 044 based. It took a lot of fin drilling and filing to get any airflow through them.

[woodsbuggy1]

Are the 049 heads what I want for torque? We hillclimb and trail ride so 90% of the time we are in 1st and 2nd gear. If there are better options for my situation I am open to ideas. I am planning to start this build in a couple of weeks and order heads by the end of July.
Thanks
Kenric

[Chip Birks]

Thanks for the input, how long did it take to get your DRD heads?

6 weeks on a 3 week quote.

[turbobaja]

It took over a year to get mine but worth the wait. John doesn't bill your credit card until they ship so no worries there. My wait was because I wanted bare castings from CB in 40x35 then have them machined. That took a delay because CB doesn't reorder many 044 40x35s. Those are usually based off the better cooling 043 or revmaster castings.

My DRDs are ancient and 044 based. It took a lot of fin drilling and filing to get any airflow through them.

This was NOT the case with my order a few years back. Very poor communication, very long extension on the "promise time", and what turned out to be a virtually useless pair of heads was my experience with DRD.

No matter where you buy your heads, even if they're CNC ports and chambers, I would strongly suggest you do a full inspection including measuring chamber volume (accurately) and removing the valves and inspect the seats before you sleep good at night like your money was spent wisely. I'd go with a set of CB heads personally, they usually have them sitting on the shelf ready to ship, and will be more than happy to assist you with any problems you might have with their product.

[Steve Arndt]

049, 043, revmaster, etc. are what most porters are using now. They will run cooler than the 044 casting. For your baja go that route.

044 is better for turbo and deep flycut. My heads are cut 0.130 inch deep for super high compression. This would weaken a stock style head too much and make them a 7 fin head.

[woodsbuggy1]

I have been hearing very good things about the 049 RevMaster heads and like the fact that they use 12mm plugs to help prevent cracking. I am shooting for 8 to 1 compression ratio so I require a large combustion chamber to achieve a tight deck.
Is anyone running heads with 40mm intakes and 37.5mm exhaust valves with a turbo? Are the larger exhaust valves actually a benefit ?
Keep all the info coming it is much appreciated
Kenric

[Chip Birks]

I have 44x37.5 heads. The big valves do just fine with the turbo.

[volksbugly]

IMHO you want the more square valving in a turbo engine, but for me its all theory. My test case ie.. Built engine is in the garage. I feel its beneficial for more seat surface are which helps keep the valve cool and better exhaust flow. Since the engine is a system that has input and output to minimize differences between " input and output's" speed and density normalizing variables in the engine is important. This only holds true on forced induction. When you start dealing with reversion issues that's a branch of output that can be tuned with header design and harmonics.

[woodsbuggy1]

Well, I called DRD yesterday and got his machine, he returned my call today and talked with me for nearly 45 minutes asking me lots of questions and taking the time to answer all of mine.
I ended up ordering a set of 40 x 37.5 entry level turbo prep unported 049 castings at $580 a pair. I expected him to try to sell more expensive ported heads but he thinks that these will best suit my needs. I also ended up ordering a cam and lifters from him.
Thanks for all of the input from everyone.
Good Luck
Kenric