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Have a FF motor, believed to be uprated. Numbers on the block read 831C 6015R34, and not the usual 711M. Anyone know what motor is this? Cotina, Kent, Fiesta, Pinto, uprated? Also, is there anything on the head to look for to tell the difference between the motors? Thanks Allan.
Allan, I am unfamiliar with that particular casting number but, put simply, if the head has combustion chambers, it's an early version - Cortina whereas the "Uprated" has a flat head surface and dished pistons. Also, to distinguish a Fiesta block from a typical 711 type block, check to see if the front cover casting has a raised part about 2" in diameter in front of the cam location. Also, there are three additional bolt holes in the block "flange" just above and to the left of the front cover. These two items would signify a Fiesta block. You can't go by whether there are four typical drilled engine mount bosses on each side of the block because many of the Fiesta blocks have them. By the way, for use in FF1600, the Fiesta block is every bit as good as a 711M so as long as the engine mounts are okay for your chassis, you're fine. Additionally, in some of the Fiesta blocks I seen lately - from salvage yards - the cylinder bore ridge is miniscule and they can be honed to the proper clearance when using the new forged pistons and thus, the cost of sleeving is avoided.
THe number you describe is not a Cortina or Lotus number, to the best of my knowledge. Might be a Fiesta CVH.
CVH head numbers are as follows:
81SM6090 - pre 1986 hemi head (1600 Escort, Fiesta XR2, Bosch K XR3i etc)
86SM6090 - Lean burn head on post 1986 carb engined models.
88SM6090 - Hemi head on the few carb engines that didn't go to leanburn in 1986.
89SM6090 - The EFi hemi head from Bosch L Fiesta XR2i's and XR3i's. Also has the injector cutouts in the inlet ports and therefore won't take a DCOE manifold without welding or other tinkering
The head casting number is found on the intake side.
A nice, brief, rundown of Kent type blocks can be found here:
http://www.lotus-cortina.com/library/block/blocks.htm
Terry,
Cortina SPU
Merlyn MK 30
Allan, the 831C is a uprated kent block (from a "service motor" I think) and is one of the block numbers listed in the SCCA GCR as a legal block for use in FF. It should work just fine.-Dave
I believe this is what I'd call an industrial motor or application. Kents apparently are also found in agricultural , marine and stationary uses. I have no idea how Ford would have identified these blocks but this number might well indicate that purpose.Quote:
Originally Posted by Dave Hopple
Thanks for all the responses. Will be taking off the head to see if the chamber is flat or chambered. But this brings up a new question. I have another FF with a 771M casting (not 711M) number. it has 3 bosses rather the 4 on each side of the block which I assumed was a Fiesta block. Since it was in a 82 Reynard, the bosses didn't matter. But according to Terry, all the Fiesta blocks start with 8. Anyone familuar with a 771M block? Thanks again Allan
Yup, I got a Fiesta block sitting right here on the shelf and 771M is the number.
According to Ford, CVH and Kent are not the same engine family.
"The 1.6L CVH engine was introduced in 1981 for the Escort, Lynx, EXP, and LN7 car line... It has a canted valve head (CVH) with the valve angles to match the hemispherical combustion chambers. Reliefs are cut into it(s) "domed" pistons to match valve and combustion chamber configuration... A 1.9L CVH was introduced on 1985 1/2 models." (Ford Racing catalog 2003)
I believe the CVH is the engine now used in Spec Racer Ford.
According to this, the CVH was never used in the American Fiesta. Keep in mind, though, the American Fiesta is not the same as a European Fiesta. That may be where the confusion starts. "Fiesta XR2" and "Bosch K XR3i" were not model names used in the US.
I think someone on the Underground once speculated that the 831C block was the Kent engine fitted to Tennant street sweepers?
Hi Allan The block numbered 831c 6015R34.This is an early AX thick walled motorsport block,used here in England in formula ford.The AX letters are cast where the 831c is stamped.They were manufactured here for motor sport in the 1980s.831C then became the thick walled AX block manufactured in Port Elizabeth South Africa until 1994.I have 2 in my garage they will bore out to 86mm 1800cc if you are carefull.am building an 1800 to go in my caterham 7.Geoff
Allan, any new info on the motor? I have the same numbers cast on the motor in my Lola 340 with a cast iron head.
4D89 AX
831C 6015 R34
Also, you don’t have chassis number 118 listed for the 340/342 on the Lola registry.
I had dinner with a guy last year - Bob Holden - who used to run Fords performance vehicles in this part of the world. They were particually successful with Escorts for rally.
He said that there were some special 711 blocks made that had a higher Cr (I think) content, and they had extra "X"'s cast on the exhaust side of the block. The more "X''s the more Chrome. I've seen some of these blocks.
Anyone else aware of them