Not cheap but a good one just the same. There's $500 just in the Carillo rod and 1000 bucks in the rare Alfin barrel.![](http://img.villagephotos.com/p/2005-8/1062154/JAP-Engine.jpg)
On offer is a mid 1930s J.A.P. 4B long stroke racing engine from a parts
stash out of the Midwest Cooper F3 racing fraternity. This is the same 4B
engine that was used in flat track, speedway and grass track racing
motorcycles. The engine was pulled from a racer years ago to be rebuilt for a new race
season which, for various unknown reasons, never happened.
In preparation for the rebuild the case was cleaned and the inside coated
with red glyptol and the outside was given a spray of gray for corrosion
control on the lectron/magnesium case. The engine has had the flywheel and
main bearings fitted along with the con rod. All other parts have been dry fitted before final
tolerance and proper honing and fitting. The engine has no seals with it and must be considered
a complete but unassembled engine. The parts provided are as follows;
Glass beaded steel head
1 1/4 inlet track has a good nut and carb flange which has been blended
into the head intake port but not polished.
Good threads on exhaust outlet and chromed exhaust nut with a nice
smoothing of the exhaust port but not polished
New Titanium valve spring caps and keepers
New stainless steel valves - 1 ¾ intake - 1/1/2 exhaust
New valve springs
New steel valve guides with the option of alum/bronze if desired
Valve rocker and bushings with needle bearings are original equipment in
good condition
Complete rocker box with a small crack in the bottom edge of one rear
spring cap
Oil line from pump to rocker box and secondary feeders from rocker box to
valve guides but oil pipe unions will have to be sourced for the build
Lodge Pink spark plug (SL51?) maybe just a place keeper
New Carrillo H-Beam rod
New 80mm Arias domed racing piston with rings
Case cleaned and coated for corrosion protection on the outside and oil
shedding on the inside
Wellworthy ALFIN barrel- good fins and good clean steel sleeve
4 compression studs for head to case - good threads - stud appearance fair but useable
Pilgrim oil pump - used but on inspection appears good
Oil box has in place four oil return valves
Polished roller valve lifters
Valve cam with unknown profile
Flywheel has been polished and balanced - unknown balance percentage/may
be factory balance
New alloy push rods with good ends
Chromed push rod tubes
Magnesium timing side cover, oil box cover, oil return box and magneto stand
SEM magneto which sparks but has not been tested and needs cleaning and
new points cap. Drive side splined carrier and retaining nut for drive cog unknown maker
bronze mechanical tachometer drive to run off the magneto shaft with cable
drive end which should, with appropriate cable, drive a Smiths Chronometric
tachometer. Engine has been dry assembled only for the purpose of checking parts fit and
inventory of parts. This engine has not been built as it is excess to my
requirements. What would be required is cleaning and fitting of all parts
to specifications.
Offered at $4,500 or best nearest offer. Any questions contact
Roy H. Caldwell - CELL PHONE 406-422-9343 or 406-324-3207 email
[email protected] or
http://[email protected] September 24