Tach Drive Distributor For Crate Engine

[LUCKY13]

I'm Preparing To Install A New 575 Crate Engine In My 65 Roadster. The Distributor In The Crate Engine Is Much Larger Than My Existing Unit. I Need To Install A Mechanical Tach Drive In The New Distributor. Does Anyone Have Any Advise For Me On How To Do That? Is There A Kit Made To Do It? Can I Remove The Existing Tach Drive From My Distributor And Modify The New Distributor By Installing It?

 

[LUCKY13]

Sorry For The Typo. It Should Say 572 Crate Engine.

 

[qwik-tripp]

Best bet is to use msd 6AL and msd tach drive dist. this way you have awesome fire and a rev limiter that is adjustable.

 

[Jack]

Lucky 13:
The new, larger dist is an HEI. No, a tach drive setup cannot be bolted to it. There are some aftermarket large HEI that come with tach drive cast into body. The larger HEI may or may not fit well under your hood ... they often are too close to firewall in some applications ... I dunno about a C2.

MSD P/N 8572 is a small cap tach drive dist ... but it must be used in conjunction with an MSD spark box/ignition control.

You could use a distributor like what came in the car ... they're available rebuilt from several vette parts houses and on ebay. It'll fit right in your new 572 crate. But, pull the gear off the HEI and press it on a TD dist like what came in car.

However, if the larger HEI will actually fit under hood ... one of the tachdrive-fitted HEI would be nice ... they're available from vette parts houses for around $500-$600. They come from here http://www.performancedistributors.com/gmssdui.htm and they’re $545 It looks like this http://www.performancedistributors.com/15720tn.jpg If this will fit under hood-firewall-aircleaner … it's a stand-alone unit & it’d probably be your best bet ... if it'll fit.
JACK:gap

 

[tigernut]

Here is the MSD distributor referenced above:
http://www.msdignition.com/dist_11.htm

Doug

 

[67HEAVEN]

Here is the MSD distributor referenced above:
http://www.msdignition.com/dist_11.htm

Doug

That's what I used too.

CLICK (way down the page)

 

[Lucy64]

I had a new 350 built by EngineFactory.Com that I dropped into my 64. I had them install the MSD with the 6AL box and it is running great. I have seen an HEI on the market with the tach drive but I highly suggest the MSD route.

 

[74bigblock]

Mid America has their Tach Drive on sale for $400. This is a VERY good price.


http://www.madvet.com/shop?frame=1.140.1166

Check it out.

Dave

 

[Viet Nam Vett]

Mid America has their Tach Drive on sale for $400. This is a VERY good price.


http://www.madvet.com/shop?frame=1.140.1166

Check it out.

Dave

The MSD Can Be Had at Jeg's for $309.95 Just bought one ..It's better built then the Mid America Unit..
http://www.jegs.com/cgi-bin/ncommerce3/ProductDisplay?prrfnbr=15584&prmenbr=361

 

[74bigblock]

The MSD Can Be Had at Jeg's for $309.95 Just bought one ..It's better built then the Mid America Unit..
http://www.jegs.com/cgi-bin/ncommerce3/ProductDisplay?prrfnbr=15584&prmenbr=361

It's better because??


A) you have to drill into your firewall and add a box that doesn't belong under the hood?
B) because you have to ground that box to something, which can come ungrounded at any moment?
C) Because it is suceptable to heat damage being an electronic component instead of a mechanical component (how much heat do you think a 572 puts out??)?
D) Cause you say so in your infinite wisdom?

... If you are going to shoot me down... at least give some reasons why you think the MSD is better than the tach drive (BTW there is nothing wrong with the units... I've had mine in with no issues. In fact, it's prob the best investment I made in the car besides the original purchase price).

D

 

[cbernhardt]

572 question

Lucky13:

I can't help you with the distributor question, but I do have a question about your 572. I just received my 572, 620 HP engine and there was no documentation, wiring instructions, start up procedures, etc. Did you receive anything with your engine?

Thanks,
Charles

 

[IH2LOSE]

I just received my 572, 620 HP engine


Boy oh boy Charles,that sounds like a lot of motor.You had better double check all of the welds on the frame,

I have been drooling over that motor loong before it became available for sale,(way out of my budjet though) Here is a link to a web site with start up procedures.

http://www.gmpartsdepot.com/572stup.html

 

[Jack]

parts-repairs

I'll add this to the MSD v. HEI discussion.
I have BOTH. The MSD is well made, works great for racing and also looks cool. The HEI clones with a tach drive use the same TYPE ignition parts as an OE HEI. The MSD tach drive distributors' ignition parts are unique to MSD.

If you're on the road with an OE HEI or HEI clone, and a pickup, coil or module fails, you can get replacement parts nearly anywhere parts are sold. That probably won't be the case with MSD tach drive distributor.

Doesn't matter if HEI has tach drive or not ... as there's a disparity in ignition parts availability between ANY HEI and an MSD tach drive distributor. Also, MSD's tach drive distributor requires an MSD or similar spark box ... and if the box fails, nobody but a coupla shops in USA can fix it and boxes are not readily available at just any old parts store. Bottom line ... if tach drive MSD fails on road ... you're probably stuck ... but if any HEI fails you can find "bolt-in, get it home" parts/service just about anywhere.

Recent rules in Nascar (cup, busch & truck) require all ignitions be located on top of dash. So now you can see the setup from the incar cameras' viewpoint. Look closely and you'll see TWO MSD boxes and TWO coils ... unseen is their race-only MSD distributor that has TWO pickups. This way, the driver can switch to another "backup" ignition system when the primary system fails ... happens routinely. MSD tachdrive dist P/N 8572 has only one pickup and a second "backup" pickup cannot be "bolted in." Of course, HEI cannot be readily setup with backup capability either ... but you don't see them in upper classes of Nascar ... nor do you see tach drive MSD in same classes. You can be sure those teams travel with many spare distributors, coils, pickups and boxes ... and there are plenty of trackside vendors with same. Let's not leave Crane out ... it makes & supports a redundant race-only setup too.

Both MSD and HEI are good systems. Either has advantages, limitations & risks. What's risky in one application simply ain't a problem in another.
JACK:gap

 

[Hib Halverson]

I'm Preparing To Install A New 575 Crate Engine In My 65 Roadster. The Distributor In The Crate Engine Is Much Larger Than My Existing Unit. I Need To Install A Mechanical Tach Drive In The New Distributor. Does Anyone Have Any Advise For Me On How To Do That? Is There A Kit Made To Do It? Can I Remove The Existing Tach Drive From My Distributor And Modify The New Distributor By Installing It?

Remove the dist. in the crate motor and replace it with your existing dist.

Or....install the MSD Corvette dist. It has a mech. tach drive and a vac. advance and is probably a better choice for a 572 cuin crater.

 

[Ken Anderson]

A stock, up to spec, 65 Corvette distributor will work fine and is VERY reliable. MSD=May suddenly die.

 

[bossvette]

one quick question Isn't the 572 a "tall deck" and don't they require a different distributor?

 

[Jack]

one quick question Isn't the 572 a "tall deck" and don't they require a different distributor?

Darn good question. Yes it's a tall deck motor ... that often indicates need for slip collar or longer distributor. However, it seems recommended distributor GM P/N 88961867 is a relabelled MSD P/N 8365 (no clip collar and for standard deck height). It seems the 572/620 crate's intake manifold is machined for standard height distributor. A standard height HEI distributor measures approx 5 13/16" from bottom of collar to bottom of housing casting.
JACK:gap

 

[cbernhardt]

Here is a link to a web site with start up procedures.
http://www.gmpartsdepot.com/572stup.html

Thanks. I found that site but I just thought it was rather curious that there was no instructions included with the engine. Guess they figure that anyone using it should know how to hook it up.

The 572 IS a raised deck and the top of the intake around the distributor appears to be milled down about 1/4" or so. I haven't pulled the distributor yet so I can't measure the shaft length.

Charles

 

[Viet Nam Vett]

It's better because??


A) you have to drill into your firewall and add a box that doesn't belong under the hood?
B) because you have to ground that box to something, which can come ungrounded at any moment?
C) Because it is suceptable to heat damage being an electronic component instead of a mechanical component (how much heat do you think a 572 puts out??)?
D) Cause you say so in your infinite wisdom?

... If you are going to shoot me down... at least give some reasons why you think the MSD is better than the tach drive (BTW there is nothing wrong with the units... I've had mine in with no issues. In fact, it's prob the best investment I made in the car besides the original purchase price).

D

First of all.....No one is trying to shoot you down. I made a statement ...The MSD is better. That's all I said . I did not attack you personally. This is an open forum with rules that have been laid down by the owners of this site. They don't like it when members get into raging "ROD" battles. So we won't have one here.

I am entitled to my option... So are you. It's how we go about addressing one another. I have respect for you and your car . I would like you to have respect for me and my car. Also, If I make an incorrect statement I always ask that some one with more knowledge straighten me out with the correct answer. Quite a few people here tend to do the same.

If I have made any incorrect statments here about the MSD or HEI ..someone please correct me.

This is a friendly place. I am a friendly kinda guy. I try and get along with every one. It's just nicer that way.

Now ..Let's address your post....
Referring to your (A)... you have to drill into your firewall and add a box that doesn't belong under the hood?


The box you refer to is the Capacitive Discharge Electronics'..MSD #6AL.
The MSD Distributor is a Capacitive Discharge Type ignition.The HEI Is NOT.. The MSD box produces the Multi spark that fires multiple times and works with the MSD Distributor..Not just once like The "HEI" Distributor. As far as not belonging under the hood goes..there are lots of places it can be mounted in in the glove compartment or under the seat . In Fact NASCAR mounts 2 in there cars next to the driver. If it doesn't belong under your hood then you can mount it where it does belong...anywhere you want.

(B) You also say you have to(Quote) "ground that box to something"....."which can come ungrounded at any moment?"(Unquote)

Yes you need a ground..or else the MSD 6aL Box won't work.... Also MOST every Circuit in your Corvette has a ground..this is do to the fact that the body is fiberglass and most electrical circuits in the Corvette need a ground as well as a Positive feed.. although not all do.
Do you think that they could also come ungrounded at any moment????

(C)Quote"Because it is susceptible to heat damage being an electronic component instead of a mechanical component (how much heat do you think a 572 puts out??)?"Unquote

The HEI Distributor contains a reluctor which produces the impulse for the spark. This small Impulse is then Amplified by a small amplifier inside the HEI Distb. This is an electronic component. This amplified pulse is then used to feed and fire the Ignition coil which is also inside the same HEI Distb. ..Another Component. This whole assembly set's inside a big Plastic housing called the HEI Distb Which Sits Directly on top of a Hot BB motor. Not the best way to keep your electronic components cool by putting them inside a plastic housing on a hot motor with no way to cool them. The MSD Distributor has NO electronic components inside. All of the electronics are in the MSD6AL box which is placed in a Cool area not hit with heat from the motor or hot air from the radiator fan.

The MSD Distributor only contains a "Relucktor" which is nothing more then a cast metal 8 legged device that spins in front of a coil of wire . Also the advance weights and the the rotor. This small pulse that is generated by the relucktor is fed out to the MSD 6Al Box for amplification which then triggers your ignition coil. Your coil can be mounted anywhere even inside your car. Your coil then fires thru the MSD Distributor and to your plugs.

Heat does not effect the MSD Distb. It also has precision bearings as well as top quality Billet aluminum construction including a grease fitting on the side of the unit for the tach drive gears. There are many more important design features that I have not mentioned. If you would like to find out more about MSD..Visit there web site..

There is nothing wrong with GM's HEI Distb. I think Mid America Sells the Tach Drive unit for around $400.00. The MSD is a much better value for just a few dollars Less.
I have an HEI in my Supercharged 86 Vette. It has given me many years of good service except once when the coil burned out do to heat stress. I also have a MSD 6AL Box hooked up and running with the HEI Distb.

D) Cause you say so in your infinite wisdom?
[size=+0]No...There are plenty of people smarter then I am on this forum. And your not the only one that came from a world of S _ _ T. When you were where I was ... then we can compare S_ _T.!! [/size]



I hope I have addressed your last post . Remember..I am not here to insult or attack you or anyone. But I will exercise my right to my opinion to say...It Sucks..

 

[Jack]

For clarity only: In addition to a reluctor ... ALL MSD and ALL HEI have at least one pickup (magnetic/Hall effect trigger) in them that can & do fail. An HEI has an internal module (amplifier) while tachdrive MSD's counterpart is a required, externally-mounted spark (CD) amplifier box ... BOTH module and spark box can & do fail. Nascar (cup,busch,truck) ignitions are no longer beside driver/on tunnel etc, for about the past 2 seasons they're required to be atop dash (it eases inspection/detection of illegal traction control).

While both are internal, an HEI's pickup & module are discrete units ... they're both separately replaceable but both are internal and both are typically in stock at local parts house ... same goes for HEI in-cap coil. Tachdrive MSD has internal, replaceable pickup and external replaceable box ... but you're not likely to find either in stock at local parts house.

Yes, some later GM HEI applications have an external module ... but the big cap HEI is what we've been referring to and it has internal module. Also, big cap HEI typically has coil mounted in cap ... but the coil can be externally mounted (i.e. MSD P/N 8401).

Insight: Likely I'll soon be driving an early C3 survivor (with points-condensor ignition) from midwest back here to SC. Since chevy quit with points in about 75, I KNOW that points/condensors are not nearly so available at parts houses as they once were ... so in my kit I'm packing a spare set of points&condensor.

Question: Pretty fair observation MSD parts are no more available than points ... so what kind of STREET ignition would you choose if parts availability were paramount?
JACK:gap