Original GT40 Mk1 engine year

[Doc Watson]

Can anybody confirm that a 'original' GT40 Mk1 engine would be a 1966 302? 6 bolt bellhousing. I know that the early Mk1's had the 289 engine but I would preferr a 1966 block. Were there unique casting codes used for the GT engines?

Also (and this is a long shot) where could i find such a block? I'm activly looking and have found some 1969 blocks (used on mustangs) but as I'm going down the 'purist' route would like to be as original as possible with the block.

Many thanks in advance.

Doc Watson

 

[Rick Muck- Mark IV]

Doc,
I beleive the 66 cars had "XE" marked blocks...and yes, there a few floating around-NOT CHEAP!!!

There are no 1969 289 blocks, the last 289s were used in 1968. It is possible that there may have been some service blocks cast, these could have a later than 68 casting date on them but the block engineering code would be a "C8" at the latest.

I had a nice 65 289 block that I hauled around to swap meets for years, no one ever wanted it!!!

Ri /ubbthreads/images/graemlins/blush.gifck

 

[Linder]

Hello

Try to contact this guy in netherland.He is dealing with old mustangs and sometimes have some engines as well www.geevers-classics.nl

Rgds

Linder

 

Hi Doc,
I checked on one of the GT40 blocks that we ventilated last year at the Wine Country Historics. It was an original GT40 race block. The observations that I made are that the main web looks to be standard thickness so I am not sure of the structural differences in the blocks. Most of the modifications can be done yourself to replicate the look of an original. Most of the stuff is standard hotrod stuff but some is interesting. Here are the differenced I noted.

Casting # XE-136505
only other casting # 6L10 near the casting number

Smoothed lifter valley
O-ringed block
Screw in oil galley plugs in front of block

Some of the more interesting things that were obviously done for endurance racing:
Strapped main caps. About 3/8 thick steel
The freeze plugs all had a method of retaining them. The oil plug at the rear of the block just to the inside of the rear intake gasket rail has been tapped on 3 sides of the freeze plug for small allen headed screws to retain the freezeplug. The main freezeplugs along the sides of the block had 2 drilled and tapped ( 1/4 bolts) holes on either side of the freezeplugs to retain them. On each side of the freezeplug they bolted and safetywired a 90 degree piece of brass that bent down into the freeze plug to keep it from blowing out. I planned on doing this on any engine I build for a GT40 project. Lends and bit of originality for not much work.
Hope this info helps.
Don

 

[Rick Muck- Mark IV]

Don,
The "6L10" casting is the date code....
6= 1966
L= December
10= 10th day
Obviously a late '66 block.

Rick /ubbthreads/images/graemlins/grin.gif

 

[Doc Watson]

Thanks for the replys guys..... I think I've actually found what I want its a 1966 289 HIPO block originally used on a mustang.... just waiting for the casting numbers to confirm.....

 

[DON SILAWSKY]

[ QUOTE ]
Doc,
I beleive the 66 cars had "XE" marked blocks...and yes, there a few floating around-NOT CHEAP!!!Ri /ubbthreads/images/graemlins/blush.gifck

[/ QUOTE ]

My $0.02, based on lots of digging around for info over the past few years, and contradicted at times by inconsistencies: 1966 GT40 Mk I Race Coupes had "C6FE" 289 CID blocks. GT40 Mk I Road Coupes were equipped with the 289 CID "HiPo" block. I have spoken with other owners of original GT40s, mechanics who worked on them for race teams at the time, etc., and the original installation of the C6FE block in the race coupes seems pretty solid. What I still don't know with any certainty is how the C6FE block differs from a HiPo 289 block. Both are 2-bolt main bearing cap blocks. One theory is that Ford picked HiPo blocks off the production line and gave them more careful treatment and machining before they were issued to teams racing GT40s. The special handling warranted the different casting number (C6FE vs. C5AE for a HiPo or C6AE or possibly C6OE in 1966). But if that is true, and HiPo blocks were picked off the production line, how did the "casting" number on the block get changed? In late 1966--and this is confirmed by the casting number of the "XE" block mentioned in this thread--Ford developed a replacement for the 2-bolt C6FE block that had 4-bolt mains. This is the "XE" and was the forerunner of the 302 CID Boss motor. The XE apparently is a much better block than the C6FE so soon became the motor of choice for anyone racing Mk I GT40s in 1967 and beyond. The Gulf Team GT40s were originally equipped with XE-block motors, and I'm guessing that many C6FE motors were junked in favor of the XE. Today both blocks are fairly rare, although the C6FE appears to be the more-difficult to find. Race events or series that adhere to "original spec" rules have required some original 1966 GT40s that wound up with an XE motor to go to a 2-bolt main block, as the XE wasn't around until very late in 1966 if at all. I would appreciate learning if anyone has specs on the C6FE block, and how it differs from a HiPo. BTW, I did a chart of the engine numbers shown in Ronnie Spain's book for each Mk I GT40. Although I cannot positively equate a particular engine ID number from Ronnie's book with a particular type of block, there are consistent differences between the ID numbers used by FAV for Mk I Race Coupes vs. Mk I Road Coupes. All this is just part of the quirky history of these cars. Again, this is just my $0.02 and could be contradicted by better information.

 

[JimmyMac]

All of the five XE blocks that I have seen have 6 L 10.
This apparently is a pattern number used at Dearnborn.
Please see my thread on Original Parts.

 

[Ian K]

From what I have understood (and this goes backa few years
to when my brother bought a '66 Mustang for about $150),
there is no difference bewteen a regular 289 block and a
HiPo 289 block. The heads are where changes were made, as well
as the main caps and con rods (the con rods eventually were
also used in the 302 Boss). There were a few pther mods, but
these are the main ones.

Here's a good site with some info:

http://www.hipomustang.com/images/hipoeng/

Ian

 

[JimmyMac]

Ian,
I also have a HiPo motor (built from NOS parts).
A true HiPo motor may have a common type block with some upgrading but the the rotating assembly was completely different.

Quite apart from the heads, the stronger rods and caps to suit, the crankshaft was batch tested for metallurgical integrity and was retrofitted with an external balance weight or hatchet.
These cranks are now extremely sought after, albeit that they are cast. The piston heads were also of high compression profiles.

The recent thread on the NOS crankshaft on the Hipomustang site shows my actual crank.(nice pictures by the way)

 

[Rick Muck- Mark IV]

JimmyMac,
That is a date code..that all the blocks you have seen all have the same date code makes sense...how many days do you think Ford would need to cast ALL of the Mk I blocks? Considering that Windsor did a couple of THOUSAND castings a day, a hundred or so blocks would not be a sweat for one shift. /ubbthreads/images/graemlins/shocked.gif

Rick

 

[Keith]

I would agree with that. I changed out a "ventilated" original hi-po 289 block in my Shelby GT350 and the replacement out of a fairly standard mustang was identical apart from the caps, rods and heads (all re-used). Apart from the block casting nos. therefore, I consider I retained an original hi-po 289 motor unless the metallurgy was different, which I have not seen any evidence to support.

I would add that I performed a number of modifications to the block as a matter of course such as completely de-burring, (removing all casting flash and sharp edges) screw-in brass core plugs, screw in oil gallery plugs, polished lifter valley. I didn't run to 'O' rings as I was only running 10:1 and the Felpro gaskets used with studs instead of head bolts easily coped with this.