Just as racers sometimes change engine builders DRO is changing engine gurus. It wasn't that the guys we have had, Don Kirn and Tom Klein, aren't highly competent because they are; it was just that their business wouldn't allow them the time to answer our readers' questions.

So we had to find someone else. We called upon old friend Scott Walker who certainly has the qualifications: he has worked at several name engine shops over the years, worked at the Frank Hawley school, and had his own shops, both engine and chassis. He has recently started a new engine/chassis business with Bob Braun, who is experienced in the sprint car and street-legal racing scene. This guy will be around for a while as Editor Jeff Burk reportedly has compromising photos of Scott Walker in the DRO files.

So, if you have an engine question, just send it to horses@racingnetsource.com and then watch this space for an answer from Scott.

Question 1:
I have a new 1970 LT1 short engine assembly with steel heads with hardened valve seats and 64cc chambers with (I believe) 10.5 or 11-1 pistons. I measure compression at 10.6-1.

What do you feel is a safe cr for street use - 93 octane pump gas - with steel heads? I would like to use as much as possible, but would be willing to change the cam or cut the piston domes down. Cam is 242/254-115 @ .050 lift hyd.

Thanks,
Dave Christie

Answer 1:
You're right, Dave, the compression in an LT1 is rated at 11;1 which is too much for today's gas. I suggest that you use Fel-Pro head gasket #1044 which is .051-inch thick with 4.160 bore diameters. This is an inexpensive way to take compression out; it should knock it down to 10:1.

Now you can use 93 octane gas and I would add octane booster.

Keep in mind that your 115 c/l cam is designed for 4-speed application.

Scott

Question 2:
I am 18 years old. I own a 1974 Camaro and I was wondering if you could give me some advice on my engine. It is a 454 bored .60 and ported 119cc cast heads, flat top pistons. The cam is a 540 intake 228 @ .50 and 540 exhaust 238 @ .50. I also have a performer dual plane intake.

I raced it last year and ran 9.2 in the eighth-mile. This year I want it to get into the mid 8's but still be drivable on the street. Any ideas?

I also ran a Holley 4150. I think it was about a 600 cfm. It also has a cast crank. Anyway I want it to contend on the strip and also be feared on the streets. What would you do if you were me?

Shad Tenold

Answer 2:
Shad, Sounds like a fun ride that you have put together. A 468 with flat tops and 119cc heads is around 8.5:1 compression.

Here are my suggestions:

1. Up the compression to 9.5:1 and you can still use 93 octane pump gas
2. You can use a little more cam, in the .600 lift range.
3. If you do both of the above, then step up to an 850 Holley Double Pumper.

This should get the results you are looking for.

Scott

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