Rapido Big Valve Head

[jkxr4ti]

I have a big valve head from Rapido purchased back around 95. It came complete with new cam A231 wich i understand is the same cam as in the later xr's. It also has the double valve springs.

I was wondering if Rapido's big valve heads were actually from ford or if they had stockers upgraded with bigger valves? If this is indeed form ford, did those motorsport heads have different casting numbers from the stock XR heads?

Peter C and I spoke at the Glenn a little about this as he recently purchased a big valve ford head from Ebay. We were both wondering if there was any way of identifying one?

[xrian]

Nothing special. It is just a stock casting that was rebuilt by MP using larger valves. Some had "O" rings cut into the head. Mild port work work was done but still much room for improvement. If it used the MP roller cam which had no base circle, you would need to do much reworking of the valves before a normal type cam could be used.
In a nut shell, you'd be way better off spending the $$ on an aluminum Essy head.

[anglin]

It is just a stock casting that was rebuilt by MP using larger valves. Some had "O" rings cut into the head. Mild port work work was done but still much room for improvement.

Hargh? So what you are saying is that Rapido was getting their big valve cylinder heads from Modern Performance in 1995? If this is true, this is amazing.

[jasonty]

to the best of my knowledge, the old rapido big valve head was the FMS head. i dont know what there talking about in the other replys.

I have a big valve head from Rapido purchased back around 95. It came complete with new cam A231 wich i understand is the same cam as in the later xr's. It also has the double valve springs.

I was wondering if Rapido's big valve heads were actually from ford or if they had stockers upgraded with bigger valves? If this is indeed form ford, did those motorsport heads have different casting numbers from the stock XR heads?

Peter C and I spoke at the Glenn a little about this as he recently purchased a big valve ford head from Ebay. We were both wondering if there was any way of identifying one?

[fastmaul]

It is just a stock casting that was rebuilt by MP using larger valves. Some had "O" rings cut into the head. Mild port work work was done but still much room for improvement.

Hargh? So what you are saying is that Rapido was getting their big valve cylinder heads from Modern Performance in 1995? If this is true, this is amazing.

That it made any power?? yeah, I agree...LOL

[xr4racing]

Hi Jeremy (and everybody),

I don't see any firm answer here so far. If somebody knows the story on the 'Ford Motorsport big valve head' please share it.

I recall from being around these cars since the early days of '84-85 hearing that a big valve head was available through Ford Motorsport dealers. My only confirmation of that may be hearing it from Russ at Rapido 20 years ago, and then asking him again recently.

Could be that Ford had some outside shop make the head for them (if there is any such thing that is).

Mine came with the A230 kit (A237 cam, rollers, sprocket), big valves and a few more goodies. My vague recollection from 20 years ago matches that the Motorsport head came with the A230 kit.

Yes you could just build a big valve head with the same parts or whatever parts you want.... but what we're trying to do here is confirm there is such a thing (as a big valve head from Ford), and how to identify one.

Although I vaguely recall seeing it listed in a Motorsport catalog.. that could be my imagination. Anybody got the catalogs they can look through for us or any other confirming info? Jason??

Thanks,
Peter
XR4Ti-IMSA

[MarkM]

From the 1994 Motorsport catalog:

2.3L OHC Cylinder head assembly - M-6049-A231

Here's a great package for "bolt on and go" fans. Cast iron cylinder head features "D-shaped" intake ports with combustion chamber volume of 62.4cc. Intake valve shrouding had [sic] been deleted. Cylinder head is machined to accept motorsport valves. Current heads include exhaust valve seat inserts. The assembly comes with the following motorsport components:

M-6507-B221 Intake Valves (4) 1.89" Dia.
M-6505-B221 Exhaust Valves (4) 1.59" Dia.
M-6250-A231 Camshaft (1)
M-6513-B221 Valve Springs (8)

Also included are (8 each) of the following production-type parts: Tappets, Valve Stem Seals and Valve Rocker Arms.

[GeneticRehab]

Well I just happen to have my 94 catolog here on my desk. It has not moved off of here sence Carlsile. LOL. Everything that Mark typed out is correct. Here are the cam specs though:

Hydraulic. Flat tappet int=268 exh=268 int lift .400 exh lift .400

I really don't think that the casting number is any different that any other turbo d-port head. Unless you look at the ranger dual spark head. But I may be wrong. I'm aways wrong. So don't rely on me. Lol.

Did you know that you could have bought a Cosworth 2.0 n/a motor from Ford in 94. Here is the part number for that one for the needy M-6002-C200*

Just my .02 cents IOU.

Oh. and were you refurring to me as Jason? He said refur. LOL.

[jasonty]

im 100% positive that the Rapido head was the same as the FMS head. i was looking at an old SVO cat and the Rapido cat. today. Now the question is ...did Ford make the head, or did Esslinger do it? in the 99 SVO cat. there is also the Esslinger Alum. Head..

Hi Jeremy (and everybody),

I don't see any firm answer here so far. If somebody knows the story on the 'Ford Motorsport big valve head' please share it.

I recall from being around these cars since the early days of '84-85 hearing that a big valve head was available through Ford Motorsport dealers. My only confirmation of that may be hearing it from Russ at Rapido 20 years ago, and then asking him again recently.

Could be that Ford had some outside shop make the head for them (if there is any such thing that is).

Mine came with the A230 kit (A237 cam, rollers, sprocket), big valves and a few more goodies. My vague recollection from 20 years ago matches that the Motorsport head came with the A230 kit.

Yes you could just build a big valve head with the same parts or whatever parts you want.... but what we're trying to do here is confirm there is such a thing (as a big valve head from Ford), and how to identify one.

Although I vaguely recall seeing it listed in a Motorsport catalog.. that could be my imagination. Anybody got the catalogs they can look through for us or any other confirming info? Jason??

Thanks,
Peter
XR4Ti-IMSA

[grve66]

rapido sold the FMS head. the sell ford motorsports parts. what so hard to understand.

the head was done by ford end of story. the essy head in the catalog was available through ford motorsports catalog but it came from essy.

essy was not doing "turbo stuff" back then.

[Snake]

The aftermarket iron head B Chandler mentioned was available from SVO Motorsport back in the day. They discontinued it sometime in the mid to late 90's. It was an iron head developed in the 80's by SVO Motorsport with help from Esslinger. It had improved intake and exhaust ports for better flow, Larger valves, Thicker deck surface, and a few other features that escape me at the moment. The part number was M6049-A231. So if you happen to run across one of these heads in good condition at a reasonable price it will give you abit more power over the stock head and be a nice piece of nostalgia.

[DPDISXR4Ti]

Holy 12 year-old thread re-ignition!

I don't recall this thread, and I certainly don't recall Ian's claim that MP built the big-valve FMS heads! Not sure what he was thinking that day.

[merkurdriver]

Holy 12 year-old thread re-ignition!

I don't recall this thread, and I certainly don't recall Ian's claim that MP built the big-valve FMS heads! Not sure what he was thinking that day.

Right , I was just thinking the same thing....is this what we thought 12 years ago? That would be crazy

[jkxr4ti]

Well since this thread has been revived I guess I'll give an update.
The FMS big valve heads definitely don't have hardened valve seats.
I had this resurfaced a few years back and the machinist said the valves had
sunk into the seats. He builds mini stock motors and said the fms head was mostly aimed at that market and most likely why standard seats were installed in those heads by ford.
He replaced them with new seats and the head is back on the car.
So far it's been on 2 vehicles and roughly 60k miles. The seats were replaced at about 30k miles.