Don Terrill’s Speed-Talk

The first comment is be very careful porting on iron heads the second time as you have lost your 'zero' point. Unless you know exactly how much material is there don't do it. The biggest csa is at the valve area and the csa increases around the bend to the exit. This makes flow separation likely abo...

The problem with adding the extra bolt (I use a 3/8" stud) to an existing engine is this is fairly close to the bore and it distorts the bore a touch. This is one of those things you should do with a torque plate.

The Indy has a thinner deck than the Edelbrock. I'm a strong believer in the extra bolt with the Indy and particularly with a power adder.

Many things are done because they look cool or someone told them it's a good idea. Often not related to good functionality.

Secondaries completely closed. Nowhere close to the transfer slot. Tried to open them back up a bit and immediately back into lean cruise.

An update: This has been a tremendous education. The secondary idle speed screw is a massive influence. Close it down and now the carb works quite well, cruise is now 14.5-15 on the AFR, no more surge and bucking. Also jetted down 4 numbers all around. Full power may be a bit lean and I may go back ...

A few more bits of information: There is no list number on the carb as it is a custom from a carb house. It does have screw in bleeds, but not IFR. I only have blank bleeds and right now do not have the ability to drill. Looking to fix this! The cam is a 232/240 @ .050" hyd roller on a 110 lsa, 1.7/...

Thanks for all the suggestions and comments everyone. I will make use of these on the weekend to see what can be done. A bit more background is this carb was speced for my 04 EMC engine. After that for giggles I stuck the carb on the very mild 401 in the street Rambler, and was astonished how well i...

Both the primary and secondary transfer slots are fully covered, the primaries more so. There is an .085" hole in each throttle plate. I have gone looking for vacuum leaks and not found any. Another thing I will look for again, but it does idle right down and it makes enough vacuum the vacuum wipers...

I'm hoping to get some help with a tuning problem I'm having. The combo is a 426 AMC street engine, 232 hyd cam, 570 hp, 5 speed OD, 3100 lbs. I have an older 1000 cfm Holley carb from a tuner house. The carb has been on a mild 401 (440 hp) for many years and worked very well, sat for a few years, n...

Also at a higher throttle and less vacuum the cylinder pressure will be higher which increases effective compression and efficiency. The true "dynamic" compression ratio.

I made mine low so it doubles as a storage or shipping cradle. The rad, gages and systems are on a separate small stand so the whole thing takes up less room. Fits AMC and Willys Tornado.

https://www.youtube.com/watch?v=k_ud7vRnTB8

Info I have is 4.380" bore spacing. I have not measured it.

Stans calculation shows a 13% drop in flow area @ .100" lift by changing from 30 to 45 degree seats. I've gotten a little higher % reduction in flow than that but similar on a good back to back on the same heads with the same valve size. Can you imagine the flow only guys with a 15% reduction in flo...

To kill low lift flow? Seat angle is the immediate big thing. Do a drawing of actual flow area at a couple lift points and then change the seat angle and see what happens to the flow area. Big changes.