Fiat Abarth 750GT Zagato Forum
Project: Chassis # 417338
Submitted by: John C.
Date of submission: January 2022
For any questions please reach out to John. His profile is John.Chatley. You can search his member profile in the member's section.
Chassis number 100*417338
Engine number 100*456211
Recorded in John de Boer’s “The Italian Car Registry” on page 12 as produced/delivered on 4th March 1958 destined for the USA.
This was confirmed by the FCA heritage team in March 2018 (enquiry reference 35451255)
It was purchased by a Mr. John D. Sheets from Encino Car Center Encino, California on the 29 July 1958 for the sum of $3,310.00. He was the first owner registered in the state of California with the Licence plate “ PZC 753” by 1964 it had acquired the license plate “ HIP 298”
Photo taken around 1988 at second owners address in Arizona
Mr. Sheets born in 1910 was a producer at Desilu Studios in Hollywood, Los Angeles. The studios appear on many period documents including the certificate of insurance and finance paperwork.
Mr. Sheets was responsible for many of the early Tarzan productions (1947 to 1950) as well as the popular TV series ‘Lassie” between 1963 to 1970.
The car fell into disuse probably in the late 1970’s and was purchased by its second owner after a chance encounter in the mid 1980’s. The second owner was a Mr. Glen Neyenhuis. Involved in the Automobile trade, Glen was one day transporting a small car for a friend and stopped at his favorite restaurant ‘Jerrys’ on route from California to Arizona. He was approached by a man who said he knew where there was a similar car sitting in ‘the weeds’ in a storage yard. Glen asked to be shown the car and on Recognising it as an Abarth asked the gentleman if he knew the owner and gave him his phone number as he said he might be interested in purchasing the car.
A couple of days later Glen received a phone call from John Sheets and a deal was struck. The car was transported to Arizona in 1988 in a non-running condition. Glen was a collector of Fiats and had an extensive assembly of cars mostly in non-running order.
Always meaning to start a restoration on the Abarth , in 1989 Glen's son, Adam, removed the interior trim from the car and later that year Glen took all the paint off the car. The intention was to refinish the body in a ‘polished’ condition unfortunately that never happened and the car would remain in this semi disassembled condition in a garage in Arizona until 2018.
Unfortunately Glen Neyenhuis Passed away in 2012 at the age of 65.
In late 2017 the family took the decision to sell the car along with another rare Fiat Jolly from 1964. Both cars were in need of total restoration. A friend of mine, Mr. David Zumstein had known the Neyenhuis family for many years and offered me the opportunity to purchase both cars. I travelled to California in February 2018 to view the cars and purchased them from Chris (Glen's son) and Linda (Glen's wife) and shipped the cars back to the UK.
Work began on the Abarth almost immediately and the car was stripped completely. There was little evidence of corrosion – a testimony to the dry climates of California and Arizona.
The engine was badly seized and the cylinder bores corroded but in order to keep the original number engine block the block was fitted with replacement liners in the standard bore size.
The main engine components were all inspected and ultrasonically cleaned, ready for reassembly.
The original Abarth Mille Miglia crankshaft was in good condition and standard size.
Original engine number.
All suspension components were shot blasted and refinished with new bushes. Suspension dampers were replaced all brake system components were relined or replaced all Brake pipework was renewed.
Original chassis number.
Unusually, the car was fitted with plexiglass side and rear windows and it was necessary to commission/remanufacture these items.
Replacement rear screen in place.
The car had originally been delivered in what was described as ‘cream’ exterior and green interior. It was decided that the interior would be replicated as closely as possible to the original colour but the exterior ‘needed something more’. So, after some consideration, the following paint scheme was decided upon.
Front screen replaced, note original alloy trim. New alloy fuel tank made from original pattern.
Interior was retrimmed in original materials and colours. Seats and carpet, head lining, RH door, and control levers
After many hours of work and some delays due to the pandemic, the car will be registered in the UK January 2022.
As soon as travel restrictions are eased, the car will be transported to Turin, Italy to be put through the official Abarth certification of Authenticity.
Detailed Engine Rebuild
When I acquired the vehicle i was fortunate that the car was in very largely unmolested condition and had its original Mille Miglia spec Abarth engine.
However the engine was completely seized (blocked) from years of sitting unused.
One of the priorities of the restoration was to retain the original engine and have a ‘Matching numbers’ car which has become very desirable in the collector’s market.
Upon stripping the Engine it became clear that the original cylinder bores had suffered badly from corrosion and that if we needed to retain the original block it would be necessary to recover the block either by re-boring or fitting cylinder liners. Close examination of the extent of the corrosion suggested that the normal re-boring sizes would not clean up the bore sufficiently to be serviceable. The decision was taken to fit ‘cylinder liners’ which would be refinished to the standard bore size.
This strategy also had the advantage that we could reuse the original ‘Borgo’ pistons with the correct crown profiles to retain the factory specification compression ratio (C.R)
Abarth standard bore and stroke dimensions were 61mm x 64mm and the 61 mm bore was not used in any standard Fiat specification so now we had to find a source for two key components. Firstly the cylinder liners and secondly replacement rings to fit the original pistons.
The first issue was solved after a visit to an engineering show here in the UK where we located a company providing thinwall liners to the general automotive industry. They had a product not specifically designed for the application but that could be adapted for the task.
The second piston ring problem proved surprisingly more difficult. Again it was the 61mm bore that appeared to be the stumbling block and at first we could only locate rings suitable for 61.5mm bore size however after some internet searching we located a company in Holland who could supply a suitable ring. Slightly deeper in section than the original but still with sufficient clearance to work with the Original pistons.
All components were Ultrasonically cleaned, the cylinder head was stripped and all valves replaced and then once all components had been thoroughly inspected reassembly could begin.
The engine block had been cleaned after machining and having the liners fitted and a fresh coat of paint on its exterior completed the job.
As mostly the original components were reused reassembly was in general straightforward.
The cylinder head gasket was originally a copper-asbestos item and a replacement was obtained via the Local Abarth specialist here in the UK from a supplier in Italy, although there was some confusion as to the bore spacing.
The replacement rings were individually gapped to each cylinder. Block ready to accept cam followers and camshaft.
Camshaft installed in Block -note liberal use of “graphogen” on the lobes. Crankshaft installed. Checking crankshaft end float prior to installing pistons and rods.
A Vernier adjustable timing gear and chain set were chosen to ensure accurate cam timing. Initial setting was made from the cam follower lift- this would be rechecked after the pistons had been installed and exact TDC point established. It would also be finally adjusted by measuring valve lift once the cylinder head had been installed. Original ‘Borgo’ pistons installed.
Bottom end assembled and all Caps torqued to specification. Note the locking taps on the main caps. The modified “Abarth” lightened and polished con rods can clearly be seen.Finding True TDC to set degree wheel and recheck cam timing
Cam timing finally checked at valve with tappets adjusted correctly. Cam was standard “Abarth” 70/30 30/70
Front cover, sump and ancillaries were refitted. All of which had been subject to thorough cleaning and reconditioning where appropriate.
Final product and installed.