740 starter motor fit an amazon ?

[red122]

Hi
A 740 starter motor is a lot lighter than an amazon one. does anyone know if it s a straight swap into an amazon please ?

[classicswede]

yes, you also need the bolts to go with it

[Army]

Originally Posted by classicswede

yes, you also need the bolts to go with it

Well that's interesting and quite surprising.

[Burdekin]

Brookhouse sell them for £126, part number B5003564. They also sell the bolts but are a bit expensive.

They are also higher torque and turn over faster so a nice upgrade.

[c1800]

Full discussion here, subject is an ES, but I think it applies to an Amazon as well .

https://www.volvoforums.org.uk/showt...Starter&page=3

[142 Guy]

If the original starter is a Bosch SR 37X then the later Bosch SR437X which was used on the red block over head cam engines starting some time in the '80s right up into the current century is an almost direct replacement. The Bosch SR 37X was used on the B20 (I have done the SR 37X to SR437X swap on my B20E) and I expect was used on the B18; but, check to confirm that).

The almost direct fit refers to the mounting bolt arrangement mentioned by classicswede. The mounting ears on the SR37X are unthreaded and on my 140 the mounting bolts are inserted from the front through the ears and bell housing with nuts on the back of the bell housing securing the bolts. On the 140 there is insufficient room between the firewall and the bellhousing to fit the bolts in from the rear. The SR437X has 12mm metric threads in the mounting ears. I suspect it is to be mounted with the bolts fed from the back side of the bell housing and the threaded ears eliminate the need for bolts. On the 140, that is not an option because of clearance. If the Amazon has more firewall clearance allowing you to insert the bolts from the back, then getting two metric bolts of the correct length from a fastener supply store may be the easiest way to go - probably 2 pounds sterling for a couple of grade 5 fasteners. The only fly in this ointment may be that the holes in the bell housing may not fit 12 mm fasteners requiring drilling.

If the mounting bolts on the Amazon have to go in from the front you have two options. You can drill out the ears so that the original mounting bolts will fit through the ears allowing the use of the original mounting bolts or you can buy two new 10 mm diameter mounting bolts which will allow them to fit through the holes without being drilled out. A bolt length of 100 mm will work; but, 110 mm is better if its available. I did my installation 6 years ago. Here is a picture of my installation plus details

https://forums.swedespeed.com/showth...=1#post2436403

As noted, it is a win-win upgrade. The starter is lighter (so the car is quicker!) and starting current is lower so the starting voltage is higher which results in higher voltage to the ignition coil and a faster turning starter motor.

I picked up a genuine Bosch rebuild which cost me around $150 Cdn delivered to my doorstep from Rock Auto. If you have access to an auto wrecker with a supply of later model OHC redblocks you might be able to pick one up quite cheap.

[Clan]

Originally Posted by red122

Hi
A 740 starter motor is a lot lighter than an amazon one. does anyone know if it s a straight swap into an amazon please ?

Its also an inferior quality one , it used an over sized permanent magnet wiper motor running at high speed and geared down with a noisy epicyclic gear train to get the torque , it sounds horrible .
you are MUCH better off using the original field coil starter it sounds wonderful and will never let you down ..