there are no free meals...

Can't hear mod you done on the conrod be done on a standard 2litre pinto engine

Is there any way the divider in the offenhauser could be machined out and the Holley retested?

I'm a bit late to the party having just seen this and it's not that different to mine - my knackered 4.6 heads were saved with a set of very very slightly bigger valves (ones that don't need new bigger seats) and like you I used the standard cam, carbs, airfilter, etc off the old 3.5. My 3.5 exhaust manifolds had been built for looks from box section and I thought were awful for flow but I still got the same as you, 201bhp and 291lb/ft so maybe they're not so bad after all. The difference in driving is just staggering, it's definitely the best engine mod you can do IMHO. 4mpg better fuel consumption too :)

awesome test. would be good to measure manifold vacuum on tests like these.

195hp is the max for the small bore. That’s my guess

hoe veel kan een pinto op zijn max halen 2.0 of 2.3 . geen turbo shit

Hi Graham, I've seen that you've done a few Rover V8s on here and I'm looking at swapping out the tired diesel in my 1990 Land Rover Disco for a V8 with ~200hp. Based on your experience, would you recommend a 3.5 or 3.9 engine as a used base? I'm wary of the issues these engines have with cracked blocks and with liners, I'd like something that will last. Or would running on carbs be a better option for simplicity, assuming you can get that kind of power from a 3.5 on carbs? I've been looking at Canems distributorless ignition systems to stop it coughing in the wet, with either the EFI or carbs.

kzfaq.info/get/bejne/etKWoNlkqZewqac.htmlsi=uckileBGwd8MGb2o Pintos and cosworth are shit vs Mazda bp power!

Comment for engagement and to encourage you to continue your good work 👌🏻

One more question: When boring the chokes, would the jet size have to be adapted? If so, means bigger choke size a bigger (bc more airflow) or smaller (bc less velocity in venturi) jet?

I'll add what I can re header primary sizes for 2v engines. This issue changes engine to engine based on their unique variables. Hitting 50hp per cylinder from 2v and 500cc can be tough. For engines with individual cylinders around 500-550cc, 38mm primaries work great and rev great until you have a 2v engine with an intake valve larger than 46-47mm, which allows for even larger intake ports, wants more revs, so a 38mm exhaust port and primary is not quite up for the job way up high. The best example is the Porsche 911RSR or even Porsche Carrera 3.2 engines which both have 42mm intake ports and 49mm intake valves and sometimes up to 51-52mm. The RSR engine has very large 42mm exhaust ports and primary size (also 42mm) and of course revs and often makes 330hp-360hp from 3L. A standard 3.2 Porsche Carrera engine with a 38mm tubular primary exhaust manifold, even with big 48mm carbs, high compression, and 265 duration @ .050 .500 lift cams, will not make 300hp, never seen it happen unless the exhaust is ported to 42mm and 42mm primaries are used and it's revd well north of 7000. Note 911 engines, even in race form, don't get much anything out of going higher than 12:1 compression. Hot street builds with twin plugs (required) never go hotter than 10.5-11:1. The 3L Alfa Romeo Busso V6 2v engine is a different story. You can stay with the 38mm primary exhaust manifold as the intake valve on the Busso 2v head is at maximum 43-45mm or so, meaning a 38-39mm intake port is the largest one can go, thus negating the need for an exhaust port larger than 38mm. Mind you this is with 48mm carbs as well. Those variables are not all doom and gloom though, as when one has this somewhat small valve issue, you can run much higher static compression (even up to 12:1) on water cooled aluminum motors, even on the street, as volumetric efficiency of the intake makes for dynamically realizing the static ratio very challenging. A 2v 3L Busso engine can still crank upwards of 300hp+ (the most I've heard of from a 2v was 347hp, on race fuel at around 14:1 compression) with much higher static compression than certainly would be used with an RSR motor as it's just not needed nor does it benefit the RSR motor, all while running the 38mm primaries. A Busso motor likes tons of compression due to the volumetric efficiency issue caused by the lack of intake, but it can still make good power as that opens the door to playing with compression. It's not so diminishing returns as it is with the 911 engine, which has much better intakes. The 3L Ferrari 308 2v engine is not exactly a similar comparison but I'll note the stock exhaust flows some 92% of the stock intake right out of the box, while the intakes are sort of horrid. Stock manifolds are 35mm ID and that motor can be tuned to make 300hp+, never touching the exhaust, but only bumping compression (at least 11.5:1) and running larger carbs, much larger cams, and ported intake. Playing with compression is definitely a thing when the VE of the intake is lacking, all while leaving the exhaust alone if that's what one is stuck with.

Good video again. What do You think is smallest exhaust pipe OD for 200hp Pinto? When OD 51mm exhaust pipe will be restrictive?

Outstanding research and development. Thanks tons for doing this!

Hi Graham , love your videos could you please check what chokes are in the 50’s and was the small bore a 2” exit Thanks Chris

Ive seen a 6hp gain going from 45's to 48's on an 1800cc 190hp (non pinto) engine, both carbs running 39mm chokes, so id say most if not all of the gain seen was from the carbs.

I’m going high with that exhaust, don’t think it’ll be the limiting factor

Love the videos! Keep em coming much love from Holland <3

Would have liked to have seen the Simpson upgrade from small bore without the change in carbs first, just to see the difference between each manifold. Great video though, keep them coming!

and to think, you had to slap a turbo + another 8 valves on a pinto in a sierra for 204 bhp in the day...

Outstanding video, still like to listen to the induction noise!

Ashley exhaust i had bought in the past is rubbish. I had to reweld parts for flow and connection to cylinder head. Flange even was warped due to welding. I make my own exhaust headers now. Simpson build headers are better option to use. For the rest cross section of primaries is a discussion that ends up in hours. How engine is build and what it wants. generaly a high rpm engine needs larger primary tubes, but you can tune the length of it. Then would you have to use 4-1 or 4-2-1 system. It all depends, and you know that very well. testing and some more testing will be a time consuming effort at cost.

Great video graham

whats your thoughts regarding stepped pipe diameter manifolds?

I wonder 😊 wat would the small bore doo on the 50's

What do you know, your just the dyno man, lol🤣 back in the day,i never heard of the Simpson manifold, i bought an Ashley 3 piece, because the normal 4-2-1 kept breaking re mig it blah blah blah, but Ashley 3 piece was really good,it was like the handbrake was taken off, engine breath so much better and climbed the revs with vigger, but very surprised of the horsepower you got out of the motor, my set-up was BVH Kent cam dowled vernier,RL1 3,500 rpm to 7,500 rpm, and Webber downdraught IDF 44, did i have fun in that car, but my wheel horsepower was 145-150 at the wheels, but the motor was pulling nothing (mk1) but things have upgraded since then (mid to late 80's) we used Lumention ignition system then, things have progress since then, I really find your video's fascinating, king of the road back in those days were Capri 3.0 2.8i sunbeam Lotus most I walked past but Lotus we were neck a neck, if we had that motor that had the three-piece manifold(ashley) the champagne would be out, lol like we won a stage on Lombard RAC Rally. 🤣 incidently,what would a motor like that cost to build at todays cost? Back then the places to get stuff from was far and few, like Burton Motivation UK (Roger & Jamie)good lads, Race & Rally Centre (James Perkowski), your not just the dyno man, your the man that can😊.

Most manifolds are too big so smaller would have made same power, with better response.

What a Sound!!! At 7500….. 🙏🙏🙏

Without question if i had a pinto to rebuild, you id be looking up pal. Mate of mine used his Dad to do his engine work for a road rally car, his last motor was alleged to be pushing 240. Rob Roy i think he goes by.

This is very interesting…

Save £700 and spend it on tyres, you'll be doing better times You can lead a horse to water but you can't make it drink. Club motorsport in a shell🙂

Can only change 1 item at a time.

Good video as always Graham, I just wondered what you use on the end of all of those manifolds, is it similar to a one box 2.5 inch escort system (Ashley) or is it just a pipe out into the outside world. 😀😀

Love these insights. Please put the camera and a light facing down the can barrels 😊.

Wow, that was a shocker, just goes to show its not all about how much money you can throw at a project,. Nice work Graham 👍

2 :11 in and I going to say that the small bore manifold is good for upto 180 bhp.?

Great video again Sir Graham, showing that a simple manifold can make a big difference. To give you some ideas, you could try an anti-reversion chamber at the output of the manifold, or a short small bore 50mm output being followed by a tapered pipe from let's say 2 inches to 3 inches and ending in a straight 3 inches pipe. Or also small bore headers going straight onto a 3 inches exhaust pipe. Cheers from Spain!!

Great vid, what were the differences in choke and jet settings between the 45,48,50 carbs?

Small bore exhaust will do to 190bhp.

@2:15 mins in and think it will work well up till 175hp.

I really wish you had ran a test after changing only the exhaust....

Damn! I nearly got the comparison i wanted! Simpson vs tony law. But on a yb atmo. As usual, great vid 👍

Grayham maybe try a CV type controled vortex manifold. It's an anti back flow idea.. 2lte fiat + janspeed 421, to bigger CV 4to1 Gained 8 whp and pulled from 500rpm lower down. On kent race cams.

Has the rod ratio changed for the' better' with the rods? Engine sounds so balanced beautiful

Thank you for this informative video! Have you ever tested one of the big bore cast iron RS manifolds? Are they far away from the Ashley and Simpson?

Awesome, fantastic effort you have gone to to answer everyone’s questions. Great job.

Recently drove a small light car with 1650cc non x flow head, modified bigger valves but i don't know the details of it. Kent 244 cam, twin DHLA 40 with 34 chokes. It was a pig below 4000rpm, then came strong to the rev limit. Have you done any tests on a similar engine ? Any hints at what to look for or alter to gain some lower end ?

Did not see you check piston/deck height protrusion

Turbo ??????

Nitrous oxide on the menu