MSD Ignition and Quench Head History?

[Bristol603]

I am investigating running my Mopar (SB 360) engined Bristol 603 (obscure British GT car) in an historic rally event. A requirement is that any engine modifications to the car must be of a type that were known and available for that engine at the date of the car's manufacture (1976 in my case).

My car has an MSD6 unit fitted and quench-type heads. Can anyone tell me when the MSD-type systems and quench-type heads started to be used on SB Mopars?

Thanks.

[dwc43]

Mopar never used an msd box that's an add on piece. They used a magnetic pick up dist with a ecu box. Mopar performance wsells a complete kit, but dont buy an orange box they are failure prone and take timming out at high rpm. You need the Mopar chrome box, and that's not to be confused with cheap parts store chrome boxes that are just stock with a chrome cover. The mopar chrome box is a performance ign. box. We used one on our rce cars for years till we went with the msd 7al2 box. Your heads should be fine.

[Billydelrio]

The Mark V was an aftermarket captive discharge system that dates back to the late 60s or early 70s. The early LA 273 and 318 both had closed chamber haeds, but I don't know if that will qualify them as "quench technology."

There are some old MSD boxes that are not captive discharge like the 6 is. Take a look at the MSD webpage, as they should be able to tell you.

Billy

[cuda66273]

Mopar Chrome Box?????????????????????

I guess you haven't seen the test numbers on those.....they may have been good sometime in history but the new ones sure don't impress me, I'd never run one ...on anything.

MSD's were available in the 70's, I wonder if they're refferring to the quench head design on the open chamber style head?

[Bristol603]

Thanks for the replies.

The history section on the MSD website refers to "Pro Stock legend Bob Glidden was one of the first pros to take advantage of our powerful multiple sparks and capacitive discharge ignition design." Sorry to show my Brit ignorance, but when did Bob Glidden race?

My engine has Magnum heads - I was assuming the main technical difference of these over the 1976 stock heads would be the quench-type behaviour. I think I could argue that if quench-type heads were available in 1976, then the Magnum heads are just good flowing examples of this type of head. The other differences such as the pushod oiling and lack of rocker shaft aren't really giving me any performance in themselves.

I am allowed to have modifications that would have been available, even if not stock, at the date of my car 1976. I just need to prove that they were of a type available to a racer in 1976.

[panic]

Quench head used by Chrysler in 1930s. Used in V8 motors in 1955 (poly).

[Bristol603]

Thank you Panic, that's exactly the in formation I needed.

[Dr. Righteous]

If you want to know which cylinder heads are on your engine, we need the casting number. Then we can give you every spec you need. You have to remove the valve cover to get a look at the number.
As far as calling MoPar cylinder heads QUENCH heads, I have never heard of that term. They were commonly called WEDGE heads because that was the basic shape of the combustion chamber with the piston at TDC.

It might be that a wedge shaped combustion chamber cylinder head is refered to as a quench head in some circles because it isn't hard to achieve ideal .040-.045" QUENCH clearance with head milling or using a piston with a quench pad.

[ehostler]

Read his actual question before you post. He knows which heads he has. They are the magnum heads. He just needed to confirm that the quench design was used before the date of his vehicle. It doesn't matter that the specific heads were not used before then, only that the design concept was used before then.

[rumblefish360]

This is my take on this.

I'm not sure on dates for the MSD, but they have been around since the early 70's. If not meeting the dates correctly, Don @ FBO systems (cuda66273) has a new chrome box thats is said to be performing very well. The MSD is a good box if leagal. If not, Don version is a good unit out performing the OE Chrome box and no one would know.
Don, can you surrply the info and links needed?

On the heads. It's a no go. Not because quench tech was used in the 30's, but the Magnum head could be to new tech. Heres why. Some guy is going to snoop around and see when they were made. Starting in 1992. The swirl port heads started in '89 I think. To new as well. When they see the advantages of the Magnum head over the older heads and also the swirl port heads, they'll cry foul. They weren't being made then. The tech was there, but not inuse. So there could be a problem in useing tech know but not used.

I believe your soulution is in a W-2 head. They can be fully ported to over 300 cfm no problem. These heads were in catologs and on the track then. Bob Gliden used these heads and ruled the strip back then.
Heres an off trick know then but seldom used. Offset grinding off the crank. Creates more stroke. Useing hard block or other material to stiffen the bottom end of the block. This is useful in hughe overbores. MoPar legand, Dick Landy, took a 360 crank, cut it down, installed the crank in a 340 @ .060 (I believe) to make 372 cubic inches. Although custom pistons in the mid 70's were truly a fotune. Right now, there off the shelf.

Is your engine subject to a tear down and inspection after the race when the crybaby that just lost, cry's on how you whooped his tail?
If so, I'd be a little more careful on parts selection.
Roller cam and rockers are good to go.

[Bristol603]

Thank you Rumblefish - that's very useful information. Pity about the swirl port feature of the Magnum heads being too new. With your help I think I now have enough to start a conversation with the rally tech scrutineer.

When I win the rally with my Mopar engine I want to be sure the mods have been OKed in advance.

[Slant Cecil]

At one time, MSD had an ignition that the OEM electrnic harness plugged into, model MSD-7C and I think also it's predicessor, MSD404. If you can locate one, although not OEM, it may fool the inspectors because of the OEM wiring.

Cecil

[b-1ken]

"Squish" and swirl port technology have been around for MANY years. I read an article which was written in the 1920's about squish in flathead engines. Swirl ports have been used in engines for many years as well. I'm guessing that you wouldn't be allowed to use pulse type electronic fuel injection, but everything else that's used in a late 360 should be O.K.
By the way, "quench" means cooling of the combustion which is "putting the fire out". This is not desirable and occurs when the piston gets close to the head (but not close enough for good squish). Ideally, you want the piston to almost touch the head so it can "squish" the air-fuel mix into the main chamber (wedge part), with turbulence, so it can burn efficiently.

[Dr. Righteous]

OK B-1ken,

How much squish are we suppose to have.
Say zero deck height flat top pistons and run of mill open chamber wedge heads.
What about closed chamber "swirl port"heads.

My next build will be a 360 with 302 heads. Zero deck heigth Hypernutectic KB pistions, and a .040" composite head gasket.
From all my reading that would give ideal "Squish" .
Everyone called it Quench but it does sound like they got the terms mixed up.

[DartGT66]

.040" is OK, it works and it is safe. Optimizing the piston to head clearance is a pretty time & work consuming process. Basically, you set the gap, then put the engine together and run it for a while, then pull the heads 6 see if there is carbon build up on the blanc side of the chamber & piston. If there is, you reduce the gap in small increments until there no more is. I have been in to way smaller than .040", but do not know how much the benefit is. The .040" works pretty well.

[panic]

Quench patented Sir Harry Ricardo 1923.

[Bristol603]

Brilliant! I'm a patent attorney myself - I should have thought of looking there.

[b-1ken]

Originally posted by panic
Quench patented Sir Harry Ricardo 1923.

That's the guy I was refering to. I'd agree with Greg with the .040" to be on the safe side, but as he said, you could probably sneak in a bit closer. Don't try it with aluminum rods though, they require more room. I run zero deck with my B-1's with .042" head gaskets. When I was forced to use aluminum rods I used a .051" gasket. I run those engines to about 7700 rpm max. I had one noted engine builder tell me when I asked him how close "the pistons should be just knocking the carbon off the head". Hmm .. THAT takes balls! He thought about .035".

[cuda66273]

MR Bristol.....

Yes we have an ignition system that will power you up very close the numbers of an MSD box.

The entire kit...ECU Coil Cap and Rotor is introductory priced at $99.00

You can run the stock ballast resistor or our low resistance type $15.00

For racing you can wire a switch to bypass the ballast resistor and run 14V direct to the coil....no more than 2 hours continuous. This will give you 48KV in the low end and hold at 42 KV up to 7700RPM like all magnetic pick-up systems you will lose 2* of timing at 5500 through the pick-up, at 8000 RPM our box will pull out another 1*.

It is a direct plug and play unit, only the gut's have been changed.