CMI SBF Clearnce issues . . . I need help!

[mphatc]

Friends,
:boggled:
My 302 Ford now has AFR aluminum heads, to which I am mating a set of E-top CMI SS headers.

For those not familiar with CMI headers they use a custom SS adapter plate to mount on the heads, the headers mount to these.

I have two clearance issues.

A. Headers to Rocker Covers. I have roller rockers under H&M cast covers with 1" spacers as the rockers won't fit under the stock height covers.
The CMI's interfere at the outer most top surface of the H&M covers.
SImple solution is thicker adapater plates . . BUT . . . :(


B. AFR heads have a different spark plug location and angle than stock GT40P heads or other SBF heads. To access the spark plugs I need the adapter plate as thin as possible, and the headers as close to the engine as possible . . :boggled:. Or I need to R&R the headers to change spark plugs . NOT HAPPENING under the tiny Corsican hatches!

Short of my buying every rocker cover on the market, does anyone know which covers might solve this dilema??

Does anyone how to identify an alternative spark plug, something smaller, that I can install in the heads with an adapter sleeve in the plug port?

I shoulda built a Chevy . . . :bonk:
Mario

[gcarter]

I don't do Fords well....but I do own three of them. But if you look at eBay motors under big block Chevy, you'll find a ton of different fabricated valve covers.
Are there a lot of SBF fabricated aluminum valve covers on the market? If there are, perhaps that offending longitudinal corner could be "modified" to give you room.

[vonkamp]

perhaps that offending longitudinal corner could be "modified" to give you room.


That was pretty much what I was thinking as well.

You could put studs in SS adapter plate to make R&R of the headers a little more bearable. I cant imagine you will need to get to them on a regular basis. Post some pic's of your project if you can. :)

[gcarter]

As far as "B" goes, how about some really long lassting plugs like Denso Irridium????

[VetteLT193]

I gotta ask the stupid question:

Do the stock covers not fit because of drip tabs? I'm a chevy guy most of the time, so usually you just grind them off and move on with life...

I really didn't think rollers took any more room than the stock rockers, other than the shape, but I never closely compared them either.

[MOP]

Mario how much do you need? Maybe have the adapters milled at a slight angle that would cant the headers outward it does not take much, I saw it done a a big block Ford with the Chevy header adapters. Talk to you machine shop guy he can probably dope it out.

Phil

[mrfixxall]

hardin marine makes a set of valve covers for your application...the side tward the header is slanted..

Accell makes a sparkplug thats shorter then your average plug..you have to figure out the heat range

http://www.cpperformance.com/detail.aspx?ID=3453


http://store.summitracing.com/partdetail.asp?autofilter=1&part=ACC%2D0276S&N=700+115&autoview=sku

[maddad]

I had some clearance issues with tall valve covers and SM manifolds. My covers were cast also, so I ground them for no interference. The cast covers were thick enough to remove the 5/16ths I needed at the top edge.

[mphatc]

Wow, great reponses thank you!
I looked at a couple of these today while in the shop . .
The drip tabs do interfere, but the inboard surface is also real close . .
to the rocker arms . .
I like the Accel spark plug idea and have ordered a couple . . this could be a winner!!
also spent time reviewing Ebay and SBF rocker covers . . I'm thinking these might solve the problem?? Item # 190157895099
I've also attached a few images ,
On the end view note that there is a 3/8" space between the header flange and the adapter flange . .
Another image shows spark plug holes that aren't in sight . . :eek!:
Obviously there is a substantial amount of modification that I'll need to do there to access plugs but also to connect wires . . .
I kinda like MOP's idea of angle cutting the adapter flange, but don't like bolt heads that are loaded only on a portion of the circumference?? Should I be?
Mario

[MOP]

Mario what the machine shop did was to cut into the header flanges to match the angle that the flanges were cut to. I saw it assembled but it was easy to see not much had to be cut, it was anywhere near a severe angle. But then again if you can grab a set of covers that will work it has to come out cheaper.

Phil

[MOP]

Mario have you put everything in place to see just how much you really need? The one pic looks like the headers is sitting on a bolt head, the one with the header upright looks like it is slightly canted in. Grab a set of gaskets get everything in place as best you can and go from there, atleast then you will have a much better feel for what you can do.

[gcarter]

If a machine shop is going to machine the face to an angle, there's no reason they couldn't machine a spot face parallel to it to get good fastener seating.
The valve covers look good, and reasonably priced too.

[mphatc]

Phil,

BTDT, pictures are a mock up only. When assembled as designed there is interference on the H&M rocker covers. These I really don't want to modify as they are amongst the most expensive of SBF rocker covers, stupidly over priced :wink:

George,
I can see the machining as a solution, although costly as once the pieces are modified it's hard to go back . . I tihnk I'll order the other rocker covers. They look to be the lowest cost solution.

A sde note, when I started this project my goal with the Bravo converrsion and a SBF was to retain all the H&M pieces . . for the historical and originality of the boat. The complexity of this set up and all the custom stuff to use a built up SBF makes me wish I had just switched over to one of those other engines . . :frown:

I'll post my findings soon!
Mario

[MOP]

Mista U Mean Like a Cheby!

[BigGrizzly]

I have a question the bigger intreferes what I had on our 16 with a 302 with the H&M exhaust. what I did was get a agndled box wrench from Snap-on. It took a while but the manifolds won't have to be removed. One more question unless you are changing plugs every day it shouldn't be an issue at once a year or less. I do my Corsican plugs every three years and the criterion every year.That isn't much.