UNC and UNF Bolt specs. for a Ford Crossflow engine

[EdWills]

Not sure if there is any interest in this as there are a few different engine options for the Seven, but I have compiled a list of the size, thread type and especially the length of the various bolts used on the Crossflow (and possibly other Kent) engines.  A number of years ago, I purchased a spare 711M engine at an auction of bankrupt oil company stock.  The engine - with a 711M block and 1100 cylinder head (with small valves), was used as a pump engine (shades of Coventry-Climax?).  Everything was sound (block, crank, and rods later magnafluxed and all o.k.).  It came with packets of nuts and bolts, and did not include some parts that were non-essential for a pump engine.  Also at that time, a local Ford dealership was disposing of 1600 engine stock which provided extra bolts, gasket sets, and numerous engine parts to last a lifetime which I gratefully purchased.  None of the workshop manuals that I own have provided the correct lengths for the UNC and UNF bolts fitted to these engines, so it's a matter of trial and error. Neither Haynes, Autobooks, Wallage's book, or the Ford Cortina Factory Workshop Manual for 1970 provide any indication of the appropriate bolt length for any part.  Bolt thread type, bolt diameter and torque requirements are provided in many cases, but not correct length.  A publication produced by Shankle Engineering originally of Van Nuys, California, provided quite a few answers.  John Shankle was mainly involved in Alfa Romeo parts and tuning, but he branched out to include Formula Ford preparation at least into the late 1970s (his booklet is dated 1978).  He went to the trouble of identifying many of the bolts used in the 2737E and 711M blocks and heads.  As a F.F. car does not use accessories such as a dynamo or alternator, and excludes maybe a few other road car parts, not every bolt length has been identified.  Fo a couple of unknowns, I still have to unwrap my spare block, try different bolt lengths and allow them to 'bottom', then use an electronic micrometer to determine a safe length for correct part installation.  If anyone requires a mostly complete list, please let me know, or perhaps it can go in the library?  Cheers,  Will

[anduril3019]

I'm interested in the list. I'm slowly collecting parts to build a 1700 pre-crossflow on a 7llM block. 

[JohnCh]

20 hours ago, EdWills said:

or perhaps it can go in the library?

 

Just follow the submission process at the top of the Library page once the doc is final.

[SENC]

Will - Brian Buckland's book on the Elan has a good bit size list, some of which may be useful given the same block.  If you don't have a copy to check I can see about grabbing that section for you.

[EdWills]

Hello John.  I went to the library section, but it notes that I need to send a PM to post anything to both @Croc and you @JohnCh. If you prefer, I can send the list to you for perusal?

 

I had also looked at the library section a while ago regarding the very detailed list of Lotus and Caterham Sevens produced (Lotus 7 Stats 2?).  I noticed the listing for the 1982 to 1984 Caterham 7 Holbay 1700, but could not find any technical reference to these Holbay engined cars in any of the Lotus or Caterham books that I have.  I had an unrelated inquiry for Paul Dunnell (Paul's father Roger Dunnell and John Read - Paul's uncle - owned Holbay until 1992), and asked him about the 1700 Holbay listed in the USA7s library stats. The stats show it described as an 'R120'.  Note: The R120 was the camshaft fitted to the on-off 1600 cc Lotus Seven S, plus a few other Series 3 and 4 cars.  

 

Paul advised on the following:

 

"You're nearly right about the Caterham builds, and yes, it was me that built them!  They were 1700cc, (ok, 1698cc) and had the K3A fitted, not the R120.  The impression I got was that they wanted to offer an up-rated X flow, as per the engines we supplied to Lotus, and that we were to supply them.  I think, as you say, this was just a ploy to get them off the hook until they could sort out their own builds, as the 'production' came to, from memory, 3 engines!"

"I remember an issue as to the clutch spec we supplied, which was not what they wanted. Certainly sold more engines into Caterhams as Dunnell Engines than as Holbay!"

 

For anyone who has an original Holbay 1700 Caterham the following may be of interest.  It is from a 1990s Holbay parts list and brochure:

 

Type K3A  A  high torque race camshaft. Widely used for 1.6/1.8 litre rally engines and in almost universal use by Formula 1300 and Formula 4 engine builders. 

 

K3A specifications relating to use in a 1600 cc Crossflow:  

Power operating range (RPM) 3200/8000;

Torque Peak (RPM) 5900

BHP Peak (RPM)  7400 (this relates to a 1.6 litre engine)

Achievable BHP per litre = 90.6 (Holbay calculation is 90.6 x 1.6 for a 1600 engine = 144.96 BHP or 90.6 x 1.7  for a 1698/1700 engine = 154.02 BHP).

Timing Degrees 58/88 inlet, 74/50 exhaust.

Valve lift (inches) Inlet and Exhaust 0.411

Period @ crankshaft degrees (inlet/exhaust) 326/304

 

Cheers,

 

W.

 

[EdWills]

40 minutes ago, SENC said:

Will - Brian Buckland's book on the Elan has a good bit size list, some of which may be useful given the same block.  If you don't have a copy to check I can see about grabbing that section for you.

Hi SENC. That would be excellent, thank you. The Autobooks manual for the 1500 Pre Crossflow, 1600 Crossflow and the Lotus Cortina engine does show all the necessary bolts (with lengths) for the Lotus Twin Cam front timing cover, but nothing for the rest of the engines in the book. Cheers Will.

[EdWills]

6 minutes ago, EdWills said:

Hello John.  I went to the library section, but it notes that I need to send a PM to post anything to both @Croc and you @JohnCh. If you prefer, I can send the list to you for perusal?

 

I had also looked at the library section a while ago regarding the very detailed list of Lotus and Caterham Sevens produced (Lotus 7 Stats 2?).  I noticed the listing for the 1982 to 1984 Caterham 7 Holbay 1700, but could not find any technical reference to these Holbay engined cars in any of the Lotus or Caterham books that I have.  I had an unrelated inquiry for Paul Dunnell (Paul's father Roger Dunnell and John Read - Paul's uncle - owned Holbay until 1992), and asked him about the 1700 Holbay listed in the USA7s library stats. The stats show it described as an 'R120'.  Note: The R120 was the camshaft fitted to the on-off 1600 cc Lotus Seven S, plus a few other Series 3 and 4 cars.  

 

Paul advised on the following:

 

"You're nearly right about the Caterham builds, and yes, it was me that built them!  They were 1700cc, (ok, 1698cc) and had the K3A fitted, not the R120.  The impression I got was that they wanted to offer an up-rated X flow, as per the engines we supplied to Lotus, and that we were to supply them.  I think, as you say, this was just a ploy to get them off the hook until they could sort out their own builds, as the 'production' came to, from memory, 3 engines!"

"I remember an issue as to the clutch spec we supplied, which was not what they wanted. Certainly sold more engines into Caterhams as Dunnell Engines than as Holbay!"

 

For anyone who has an original Holbay 1700 Caterham the following may be of interest.  It is from a 1990s Holbay parts list and brochure:

 

Type K3A  A  high torque race camshaft. Widely used for 1.6/1.8 litre rally engines and in almost universal use by Formula 1300 and Formula 4 engine builders. 

 

K3A specifications relating to use in a 1600 cc Crossflow:  

Power operating range (RPM) 3200/8000;

Torque Peak (RPM) 5900

BHP Peak (RPM)  7400 (this relates to a 1.6 litre engine)

Achievable BHP per litre = 90.6 (Holbay calculation is 90.6 x 1.6 for a 1600 engine = 144.96 BHP or 90.6 x 1.7  for a 1698/1700 engine = 154.02 BHP).

Timing Degrees 58/88 inlet, 74/50 exhaust.

Valve lift (inches) Inlet and Exhaust 0.411

Period @ crankshaft degrees (inlet/exhaust) 326/304

 

Cheers,

 

W.

 

Should read "one-off" for the Lotus Seven 'S', my error W.

[JohnCh]

19 minutes ago, EdWills said:

it notes that I need to send a PM to post anything to both @Croc and you @JohnCh.

 

When it's ready, please attach it to a PM to the two of us and we can sort it.  I opted to point you to that page for instructions, given it's not clear when you will have a final copy ready, and that process may change -- in fact, it did on Saturday