3020 E6015 Block

[111Robin]

I've read all of the posts I can find on the subject of block identification and all seem to indicate that a 3020 E6015 is for a Mk2 Lotus Cortina. My Plus 2 engine (late '68 build) carries engine number H17535B that is correct for a Super S/E high compression engine and also has the 3020 (stamped) E6015 ID on the block. I'm a bit confused now if the Mk2 Cortina designation is correct (assuming my engine is original ofcourse which it does appear to be as the stamped engine number hasn't been tampered with) ?.

[promotor]

I wouldn't worry - plenty of Elans have a 3020e block and they are original.

Don't forget that Lotus had to get their engines from Ford so I guess Ford had some say-so on what was on the blocks supplied to Lotus.

Blocks in mk2 Lotus cortinas would have 3020e on them, possibly some early Escort Twincams did too.

[smo17003]

3020E was Ford's designation for their Cortina Lotus Mk2. Likewise 3034E was for 1300cc RHD and 3036E for 1600cc RHD Cortina's, and so on.

My ancient Cortina Mk2 part book says 3020E-6010-A for the bare block. Other Lotus specific parts, i.e. they don't (originally) fit other Cortina variants, are also prefixed 3020E. Carb's, Lotus badges, air cleaner, exhaust are all 3020E.
The gearbox internals are not numbered 3020E because they were shared with the GT (and later 1600E) and came from the earlier Corsair 2000E, which obviously had its own designation.
The rear springs and shocks on the 1600E are prefixed 3020E because they shared those parts with the Lotus, but the Lotus preceded the 1600E by a few months, I believe.
It's just how Ford's heirarchical part numbering worked at that time.

Back in the 80's I ran a Mk2 Lotus with said 3020E numbered block. Wish I still had it.

[111Robin]

Thanks. My engine number is correct per the Lotus heritage certificate, so the 3020 block is the original, supplied as a Plus 2 kit. So if 3020 is the Cortina part number, what makes it specific to that model?. Would Lotus not just use whatever blocks they had in stock irrespective of the part number ?. Ultimately I'm not bothered, it's just interesting to dig into the history.

[rgh0]

Around that time Lotus tended to come with the block casting number ground off and nothing in that place. The Ford Lotus Cortinas had the 3020 stamped on the block in the ground off place. I am sure some of the Cortina engines ended up in a Lotus like yours depending on what was on hand on the day.

cheers
Rohan

[2cams70]

Ford part numbering back then generally revolved around the vehicle that the particular part design revision was first used in. For example "105E" prefix means it was first used in the Anglia, "109E" means Capri Classic, "116E" Mk1 Cortina and so on. There are exceptions but that's the general rule. If that same design part was subsequently used in a different vehicle it still always kept the original part number prefix.

"3020E" means Mk2 Lotus Cortina. For Lotus use the blocks had the original cast in numbers altered (ground off and re stamped) in order the distinguish them in production from regular cylinder blocks with smaller 81mm bore size (that's my yet to be disproven theory at least).

The part numbering system seems to have have changed around 1968. From that date new part designs started to be introduced with a prefix indicating the design year - eg. "681F", "701M", "69AG" etc. with no linkage to the origin vehicle.

[111Robin]

Thanks all for the information. Would a Mk2 Lotus Cortina block have been delivered to the Lotus factory ?. I know the Mk1 was assembled by Lotus but thought the Mk2 was fully built at the Ford plant ?. I'm over thinking this I know, but I find these details interesting. I blame forty years of figuring out what's genuine in the world of Mini Coopers, that was bad enough with what if's and when's, build change dates etc. I am reading Wilkes' book just now so trying to figure things out.

[2cams70]

A part of a specific design is just that regardless of the vehicle. It doesn’t change name or part number depending on where or in what vehicle it’s used so provided it fits a 3020E block could have been supplied for use anywhere, a Lotus, a tractor, a boat! . Lotus however would have had their own different part numbering system for identification compared to Ford. In their system any Ford part numbers would have had a cross reference to a Lotus one. The physical part didn’t change only the reference numbers in the design drawings, part listings in the Lotus administration systems will have changed to being a Lotus one with a Ford cross reference.

[smo17003]

Ford part numbering back then generally revolved around the vehicle that the particular part design revision was first used in. For example "105E" prefix means it was first used in the Anglia, "109E" means Capri Classic, "116E" Mk1 Cortina and so on. There are exceptions but that's the general rule. If that same design part was subsequently used in a different vehicle it still always kept the original part number prefix.

"3020E" means Mk2 Lotus Cortina. For Lotus use the blocks had the original cast in numbers altered (ground off and re stamped) in order the distinguish them in production from regular cylinder blocks with smaller 81mm bore size (that's my yet to be disproven theory at least).

The part numbering system seems to have have changed around 1968. From that date new part designs started to be introduced with a prefix indicating the design year - eg. "681F", "701M", "69AG" etc. with no linkage to the origin vehicle.

Ah ha, now that makes sense because in the early 90's I also briefly owned a second Mk2 Cortina Lotus and that one had the 701M block.

Could it be that for the 3020E blocks, Ford were, at the introduction of the Mk2 Cortina, producing engines for Lotus (Elans) and the blocks were still cast with 120E (I think that's right?), and then for use in their own Cortina's the casting number was ground out and restamped with 3020E?

Just thinking out loud so sorry if that's wrong.

[2cams70]

No. By the end of ‘67 the 120E block would have been superseded and completely out of the Ford part system. 3020E blocks were probably based on a 2731E casting. The 2731E was the standard block for regular production early Mk2 1,500cc Cortinas. These had a pre-crossflow 1500cc engine with six bolt lip seal crank. For Lotus application Ford ground off the ‘2731E’ casting number and restamped to “3020E” after having bored the block to 82.5mm instead of the regular 81mm

[111Robin]

The V5 and chassis plate also have 8J16 showing after the engine number, indicating presumably 16th September 1968, should I be able to see this on the block, or does this mean date of assembly ?.

[2cams70]

The date code is cast into the block bottom LHS front. This is the date the block was cast and not date of assembly.

[111Robin]

Do you have a photo showing the format of the casting date code ?.

[Craven]

cast date.jpg (81.28 KiB) Viewed 641 times

[111Robin]

Cheers, I was looking at the circular arrangement above, I'll have another look to see what date mine is.