Rally Engine build: discussion of considerations...

[@danielruiz7304]

This dude is a national treasure as we say in America..lol

[@Triplet2bear]

Thanks for this very helpful (& charming) guide.

[@andrewcroxall1416]

Well done sir, very knowlagble and informative enjoyed this.

[@danielebbeling4056]

I bought my 1970. 142-S ; B-20; 4-sod manual ; already built for rally. This was in 1981. My reverse speed was crazy -fast. I recall wearing my clutch to use it in day-to-day use. I had great torque from the higher RPMs. Strong acceleration through the 80+ range. I was 18 then. Absolutely clueless ; mechanically. It did win my heart over, though!

[@brallybear620]

Thank you for a very nice video. I used to rallye cars with these engines in the 70:s. PV 544, Amazon and 142. Never had any problems with the engines. The 142 was kitted with pretty much all goodies that was available in the mid to late 70:s. No dyno testing because the nearest dyno (no rolling road) was 250 kms away. We just made tests on a forest road, pulled the plugs to check the colours and changed main jets in the Weber 45:s if we thought it was nessecary. Sounds a little bit crude nowadays but we drove a lot of rallyes and usually knew our cars inside and out and learned what worked and what did not. Greetings from Sweden.

[@amazoncars]

It's such a pleasure to hear from someone who competed in these cars in the 70's: thankyou. Do you have any photos that you can email to us perhaps? We've (obviously) had a quiet year, the PV hasn't competed since December 2019, I've been out in Gareth's 122S, and my daughter's 142 has benefited from the extra time available and is now Historic Cat2 eligible. I also navigated for Amy on a modern event in her MX5 as Course Opening Car; and tonight we're marshalling on the Preston Rally, a full out very rough forestry "road" rally ending at 0600 tomorrow. Regards, and thankyou again Rob

[@brallybear620]

@@amazoncars Thanks Rob! I am glad you liked it. I have mailed a couple of pictures and some "volvofilia" to your E-mail address. Please write if you are wondering about anything. I remember some things but have, for sure, forgot even more.

[@stuartvaughan2137]

Extremely comprehensive overview.

[@bayvanman]

Thank you, owning a mysterious '66 amazon which engine code shows it as a 142 B20b. This has been very informative.

[@jsand2949]

Thanks for this, really filled in some of the gaps for me. :)

[@williamholmblad5849]

Awesome video!! Really liked it. I have started my second b20 rebuild/tune, and this time i am going for more power than the last one! So this video really helps me!

[@jonobester5817]

Just beautiful. Thank you!

[@jefferyrichardson8867]

As a DIY home car mechanic, I found this fascinating because it explains from some basic principles how to make a car go faster. And, curiously, the suspension and braking modifications make the car safer right from the start. Something to think about.......!

[@douglasfox9579]

Always great videos, thank you. Can you provide some more detail on the head? It looks to be a later year head, given the P for FI, but what exactly is it? I have a F Head and a E head and am trying to decide whether to use the E in its original configuration or shave the F to E specs and higher compression (FI holes plugged for a carbureted motor). Thanks again!

[@tutnallman]

Well done about priority of tasks. what suspension angles are used on an amazon?

[@Froa2000]

Great video! Will a lighter flywheel result in rougher idle and reduced torqe at low rpm?

[@amazoncars]

We've gone down to 5kg flywheel, and with a well built balanced engine it still happily idles at 900rpm; however hill starts will need extra revs because of the reduced momentum from the engine. So, the pay off is improved acceleration, but reduced apparent torque below 1500rpm. Rob

[@VECT4GAMING]

Very good video, what was the top speed you where obtaining in this car?

[@davidferreira7243]

Great information regarding the cross drilling of the followers. Any chance you can share the process or possibly a how to video? Keep the knowledge coming!

[@amazoncars]

I confess that we don't cross drill them in-house, we send them off to our machinist to do a batch at a time.

[@kickstartedwards6916]

Great video much appreciated Read piece in classic cars June edition on the CCK volvo which now claims to have 225bhp...It certainly goes like a rocket

[@amazoncars]

We supply CCK with original parts for the PV & Amazon, and they do wonderful engineering on the mechanicals.

[@declanburke4146]

Good common sense advice Rob! I secretly prefer the SUs.... but don't tell anyone ;)

[@benlaisby3720]

Hi Rob, great video. What bhp and torque would you expect to see from this specification of engine? Thanks

[@amazoncars]

Ben, rather late in spotting your comment, sorry! I would say 125bhp, however dynos are notoriously optimistic when operated by engine builders! More important are our 0-100kmh times, which with this engine would be a shade over 10s, our PV544 runs under 10s, and the 142 in stage spec managed sub 8s. All have good behaviour from 2000rpm to 7000rpm. R

[@dorufilip3477]

Great video, sir! What kind of figures would you be able to get from a B20 engine for a daily driver ? Torque/bhp, 0-60mph and fuel economy would be highly appreciated. Thank you!

[@amazoncars]

We avoid bhp and lbft like the plague: many rolling roads are at best 10% inaccurate, and some are closer to 50% in error - entirely dependent on whether the rolling road built the engine or not. However, our "sport engines" typically achieve around 10s 0-100kmh, and very nice torque curve. Idle speed is high at 1200rpm to avoid wearing the camshaft, but they will idle comfortably down at 900rpm. Fuel economy, I'm not really sure! Around 25mpg generally, but a long trip at around 3500rpm can return 30mpg.

[@banarne71]

Great video as always. I have a d-kam and lighter fly wheel on my pv 544, b18. Do I need double valve springs or can I just use oem ones? Thanks.

[@amazoncars]

D-cam: definitely OE springs. The double spring set up is only needed on the high lift (0.5") camshaft that we supply. Beware of a nasty batch of substandard springs that are out there: only buy from a reputable source. In fact, I would say that the original springs with the engine will be absolutely fine, no need to renew, unless they are known to have had a racing life... Rob

[@satanihelvetet]

When talking about carburetors at tuned Volvo red block engines, also Solex and Dellorto should be mentioned as popular alternatives.

[@amazoncars]

Excellent addition: what's parts supply like for them?

[@grapsorz]

nice to se ;) i had a B18 with some mod's and it had a R cam. i managed to over rew it in anger. within 5 seconds i had taken out all the piston rings and lost all compression. it wold stil run just fill on the oil and check the fuel thing ;) then i got a B20 at 2.2L K cam and the rast was about the same.. the K stopped WAY earlier then the R cam did in RPM. (btw i made 135kmh in second gear... not good)

[@oleelo100]

I have a theory about the braided teflon lines if you were to use something like or similar to a crimp sleeve on the outside of the braid would that be sufficient for use in rallying? Or am i just thinking nonsense?

[@TeamHystericalPC]

Hello ive been noticing on my b20 a sort of rattle coming from the engine i tries tracking it down but havent been successfull i fear it might be timing gears cause the valve train is good the gearbox clutch and such have been replaced or been found good for instance im driving along i let go of the throtle the engine ratles till the rpm go down if i put the throttle on again the rattle is gone

[@Triplet2bear]

PS I would love to know the power & characteristics of the new cam

[@Patricks_Projects]

A lot of opinions in the video, i´m sure he want´s to sell his stuff. Here in Sweden we are revving 8000 with oem lifter and pushrod, no hassle...

[@tutnallman]

I built a 10:1 engine (B20) in 1996 and in 2022 I had to replace the cylinder head gasket. I had no idea these engines were so unreliable.........................

[@mrtordse9042]

Im wondering if its a problem or a feature that in my 142 with a b20 and m40 i cannot no matter how hard it try to engage the first gear while the car is moving which causes problems in traffic when im moving too slowly for 2nd gear but cannot engage first gear. Im thinking of installing lighter flywheel but dont know if the car will stall every time in traffic if i install that

[@MrPemellquist]

what is the specific Isky Cam did you choose?

[@thephatlander]

The b18 head has the valves more narrow each other than b20 and there for are MUCH better then b20 if done right with the right valves (b20) which should NOT be to big... Why is this? Because youbdont want the intake valve to close to the cylinder wall... Then you Will lose lots of flow! Also, when porting the head, dont go to big........ Try it! You be surpriced IF you get it right!

[@DavidSilva-vo7pk]

many thanks i a volvo4ever.... classic maniac blogspot ;) more videos

[@DanJ.Hendon]

can you wear a royal guard's helmet in the clubman races

[@jonobester5817]

What is a C grind camshaft?

[@oleelo100]

Do you have a website?

[@loetkoe27]

what oil do you run in your competition engines?

[@amazoncars]

15w40 in winter, 20w50 in summer, and mineral. Rob

[@loetkoe27]

@@amazoncars thanks!

[@goblright]

@@amazoncars I this because of terrible experiences with the synthetic ones, or is it just a habit?

[@amazoncars]

@@goblright I have no problem with using synthetic (or semi synthetic) oils, I just haven't seen the need for them, nor am I aware of any advantage that they might have in our temperate climate. Rob

[@taihund]

Are building a B20 engine and have a quistion ,double valve Springs what pressure du you have on the valve when spring at built in

[@amazoncars]

Aha, now I don't bother balancing up the valve spring pressures: for sure this will give you an even better engine, but it's kind of in the "race" league of engine builds, whereas I build road rally engines for a 7000rpm redline. But you can work it all out from the spring specifications, if your engine needs to be smoother at high revs. Rob

[@taihund]

@@amazoncars thanks 👍😀

[@arod997]

what would you recommend for alignment values for an Amazon running on modern rubber (205/60r15 tires)?

[@amazoncars]

Very much stock values except for choosing a camber of around -0.7deg (note the -ve). Caster is critical and should be +0.5 to +1deg, however running 205's the steering is still going to be rather heavy. I only use rubber that fat when competing on dry smooth tarmac (ie race circuits, or the Eifel region of Germany), outside of those conditions we've found the car to be better handling with 185 maximum width. And just a touch of toe-in: 0 to 1mm.

[@onniheikkila9884]

Do you use the original design piston rings?

[@amazoncars]

We're usually using forged pistons in our uprated motors, which have the more modern style narrow rings. I think we do see greater oil consumption due to these, but negligible compared to the rear crank seal loss at 7000rpm. Rob

[@onniheikkila9884]

@@amazoncars I replaced the oldschool one piece oil rings with new three piece rings. No more blue smoke when engine braking. I'm using Mahle pistons.

[@amazoncars]

@@onniheikkila9884 Mahle pistons are our favourite, but very hard to find now (or have they produced some more???). And good point, the 3 piece oil control rings are indeed very good. Rob

[@kickstartedwards6916]

Great video much appreciated Read piece in classic cars June edition on the CCK volvo which now claims to have 225bhp...It certainly goes like a rocket