Harris pinto dyno test

[Graham]

Yes, but when it's clear parts need changed to achieve their desired/ultimate goal......again, does the budget allow this ?

Or is it a case of give me what I want, but don't change anything and there's no money ? Which clearly cannot work.

And as said, when it was supposed to be a 2.0.....does that need factored in to race again where he wants to ?

not really, yes, no and no.

its an ex hill climb car which has bought to return to the road but he describes as un drivable on the road, so he wants to tone it down, but still have it lively enough for the odd track day. if we need to change the carbs he will, i dont think budget is a major concern, we were discussing pistons. his look rather second hand and need new rings and pins, but would go again, but he wants new ones. I dont see any point in running out and buying new smaller carbs straight off the bat when its not a forgone conclusion teh 50's wont work, and in any case we are in the position to experiment with different carbs so why not? i recently dyno'd a bmw engine on 48's with very big chokes, it was just a refresh so other than run it it and set the timing i didnt do any tuning. But what i did have to do was refit it to the car, so i gave it a drive around afterwards just to check all was well. what i found was it was way more drivable than it had any right to be given, big carbs huge chokes and a race cam, so you never know.....

[stevieturbo]

So if happy to spend, why not bump up the cc as much as possible ?

2.4 has been done I believe, and will help all round, certainly on the road, and with the carbs, and with taming a larger cam

[Graham]

So if happy to spend, why not bump up the cc as much as possible ?

2.4 has been done I believe, and will help all round, certainly on the road, and with the carbs, and with taming a larger cam

theres a big difference between buying a new set of carbs if required and buying a steel crank and custom set of rods!

[alladdin]

i would guess the 50's are worth more than some 45's anyway ?

[stevieturbo]

theres a big difference between buying a new set of carbs if required and buying a steel crank and custom set of rods!

Indeed there is, but there was no mention of budget constraints when asked.

[Graham]

Indeed there is, but there was no mention of budget constraints when asked.

do you not think i would of been making the engine bigger if it had been a viable option or i had the budget??????????????????????

[stevieturbo]

I've no idea....which is why I asked ?

[rallyrob]

A Crank and Rods has got to be all of 3 Grand Plus, hasn't it?

[stevieturbo]

I'd say you could do it for less than £3k, plus pistons of course.

But it does appear there is a limited budget, so that's out the window.

[Miniliteman]

Think there is a difference between a blanc cheque and a "what has to be done has to be done" budget.
Am curious what Graham can do with probably some smaller chokes for the 50's and a somewhat milder cam.

[Forest_rallying]

Jaysus Stevie it would be a minimum of 3 Grand for a decent 2.4 bottom end unless he went for Chinkie shite.

[Graham]

Jaysus Stevie it would be a minimum of 3 Grand for a decent 2.4 bottom end unless he went for Chinkie shite.

thats just crank and rods, never mind pistons, clearancing block and a host of other minor mods

[Forest_rallying]

thats just crank and rods, never mind pistons, clearancing block and a host of other minor mods

How are you going to reduce the 7 thou bore clearance Graham? Get the block linered, rebore another block or a new set off oversize pistons and rebore the existing block. If the Accralite pistons are in good condition I would want to reuse them proving new rings are easily available.

I am sure you can give the customer what he or she wants without spending bucket loads of money, most of the ingredients are either already there or sitting in your workshop.

[Graham]

How are you going to reduce the 7 thou bore clearance Graham? Get the block linered, rebore another block or a new set off oversize pistons and rebore the existing block. If the Accralite pistons are in good condition I would want to reuse them proving new rings are easily available.

I am sure you can give the customer what he or she wants without spending bucket loads of money, most of the ingredients are either already there or sitting in your workshop.

probably liner the block, customer doesnt want to use another block. he also doesnt want to reuse the pistons, too my eyes they are a bit secondhand looking, to his they are basically knackered, either way we also need a set of gudgen pins, so by the time you have paid for rings and pins, its not that much more expensive to by a set of pistons

[Forest_rallying]

probably liner the block, customer doesnt want to use another block. he also doesnt want to reuse the pistons, too my eyes they are a bit secondhand looking, to his they are basically knackered, either way we also need a set of gudgen pins, so by the time you have paid for rings and pins, its not that much more expensive to by a set of pistons

That’s strange worn gudgeon pins, they are normally as hard as a Woman’s Heart. I thought Accralite pistons were the dogs Danglies. Back in the day we always used Cosworth 93mm pistons, we had to buy them from a Mr Reid in Ireland, he always provided a first class service.

[Graham]

That’s strange worn gudgeon pins, they are normally as hard as a Woman’s Heart. I thought Accralite pistons were the dogs Danglies. Back in the day we always used Cosworth 93mm pistons, we had to buy them from a Mr Reid in Ireland, he always provided a first class service.

ive seen it before

pins are worn in the middle when they run in the rod, the pistons have had a modification which i think will of reduced oil supply to the small end. but it may also be the small ends them selfs have embeded dirt which will wear pins, its odd, but soft will wear away hard. i think part of the problem will be the engine has had hard use before being warmed up properly so all the movement of the pin was in the small end and none in the piston

[Forest_rallying]

ive seen it before

pins are worn in the middle when they run in the rod, the pistons have had a modification which i think will of reduced oil supply to the small end. but it may also be the small ends them selfs have embeded dirt which will wear pins, its odd, but soft will wear away hard. i think part of the problem will be the engine has had hard use before being warmed up properly so all the movement of the pin was in the small end and none in the piston

I am not familiar with Fiesta Diesel Rods. Have they already got the same size gudgeon pin as the Pinto and is the bronze bush of suitable quality for high revs with them coming out of a slow turning Diesel. Are you going for the same make of piston or trying something else?

Looking forward to seeing your progress with another video.

[Graham]

I am not familiar with Fiesta Diesel Rods. Have they already got the same size gudgeon pin as the Pinto and is the bronze bush of suitable quality for high revs with them coming out of a slow turning Diesel. Are you going for the same make of piston or trying something else?

Looking forward to seeing your progress with another video.

yes they have same 24mm pin size as pinto. it is a bronze bush, true diesels dont rev but they put way more load into components, so i cant see why the OE bush would not be upto the job.

Pistons are already here, im putting the same pistons back in, they are yb with very thick crown to allow machining to however you want them. so i will have to machine a chuck off the crown, i am un decided as to whether to put valve cutout back in or not, if a fit something like an RL31 it wont need them, but it probably wont hurt to put them back in even if not needed. in fact putting them back in would give a bigger safety margin in case of a missed gear, or allow me to swing the timing on the dyno without a care so to speak. not to mention i need to drop the compression by about a ratio

[Forest_rallying]

yes they have same 24mm pin size as pinto. it is a bronze bush, true diesels dont rev but they put way more load into components, so i cant see why the OE bush would not be upto the job.

Pistons are already here, im putting the same pistons back in, they are yb with very thick crown to allow machining to however you want them. so i will have to machine a chuck off the crown, i am un decided as to whether to put valve cutout back in or not, if a fit something like an RL31 it wont need them, but it probably wont hurt to put them back in even if not needed. in fact putting them back in would give a bigger safety margin in case of a missed gear, or allow me to swing the timing on the dyno without a care so to speak. not to mention i need to drop the compression by about a ratio

That’s a crying shame Graham to have to machine a brand new set of NA Cosworth pistons down, 93mm ones were virtually impossible to find when we were looking for them 30 years ago. Aren’t flat top Pinto pistons with a thick crown available?

Are Omega still making pistons or have they amalgamated with Accralite? I remember ringing Omega many years ago, they would only supply me some if I ordered something like 6 sets.

[Graham]

That’s a crying shame Graham to have to machine a brand new set of NA Cosworth pistons down, 93mm ones were virtually impossible to find when we were looking for them 30 years ago. Aren’t flat top Pinto pistons with a thick crown available?

.

they are not n/a cosworth they are cosworth with massively thick crowns

https://www.burtonpower.com/forged-p...-sc302-93.html

[Forest_rallying]

they are not n/a cosworth they are cosworth with massively thick crowns

https://www.burtonpower.com/forged-p...-sc302-93.html

Sorry my misunderstanding Graham. They do look like to have a good thick crown.

[Graham]

Sorry my misunderstanding Graham. They do look like to have a good thick crown.

yes they are really really thick, you can chop about 7mm off with ease

[Forest_rallying]

I have just read that they have 12mm thick crown. Are you machining both inlet and exhaust valve pockets?

I wonder why Burton or Accralite refer to them as a Cosworth YB piston and not a Pinto, are they intended for high compression Turbo use.

[Graham]

I have just read that they have 12mm thick crown. Are you machining both inlet and exhaust valve pockets?

I wonder why Burton or Accralite refer to them as a Cosworth YB piston and not a Pinto, are they intended for high compression Turbo use.

i may put both cutouts back in. In reality they are too heavy to be used without machining espcially on a pinto rod. The idea of this is to allow turbo YB tuners to machine whatever sort of depth bowl/valve cut out they like and still have a usable piston at the end of it. many years ago you used to be able to buy a powermax BDA piston with a similarly thick crown, the piston catalogs used to refer to them as "unfinished"

[Forest_rallying]

i may put both cutouts back in. In reality they are too heavy to be used without machining espcially on a pinto rod. The idea of this is to allow turbo YB tuners to machine whatever sort of depth bowl/valve cut out they like and still have a usable piston at the end of it. many years ago you used to be able to buy a powermax BDA piston with a similarly thick crown, the piston catalogs used to refer to them as "unfinished"

It just seems strange to go for a 93mm bore on a high cylinder pressure Turbo engine.

I remember seeing the unfinished pistons advertised somewhere along with engine blocks of the same wording.

[mariors2000]

Any update Graham.

[Forest_rallying]

Any update Graham.

All Pinto threads appear to be very Quite at the moment Marriors!

[mariors2000]

Hi Graham just seen video great job like always nice flow figures on new head can't wait to see what hp it makes cheers mario.

[mariors2000]

Hi Graham the rec valves your using on the harris engine do they come with a 30 deg back cut or just a 45 deg seat cheers mario

[Graham]

Hi Graham the rec valves your using on the harris engine do they come with a 30 deg back cut or just a 45 deg seat cheers mario

they come with a built in 30 degree, ie its part of the valve shape not back cut as such

[Graham]

Well i have now run it, Dropped the chokes in the 50's back from 46's to 40mm, i tried smaller but it didnt like them, i suspect thats just to much a step down in size for the incoming air to cope with and to be honest i dont the the RL31 is enough cam to make proper use of the simpson exhaust manifold, huge carbs etc but it did ok on the dyno. Curiously i had to retard the cam significantly from kents recomended figure to get it to make any real power. Remembering the goal was make the engine more drivable not give it more power, so it really doesnt make a big headline BHP number. it makes peak power around 6800/6900 which in my experience where an RL31 usually peaks, but what i like is 5800rpm, where it stumps up 181bhp

[mariors2000]

Can't wait for video to come out keep the good work coming.

[Graham]

Right its done, would i recomend 50 webers for this engine, no, but i have to say that with 40mm chokes installed they worked quite well. its quite clean in terms of taking up power on the load in and part throttle. Would it of made the same power on 45's 38mm chokes? not sure i think it would of got close in terms of peak number. but it is what it is.

https://youtu.be/r0fT5O-Zr0I

[Miniliteman]

Graham,

what is happening here? (see black circle in photo)
Looks like (hot) coolant.

[katana]

I believe its the open tank for the absorber - its a water braked dyno, hence the huge water tanks G had to add outside the dyno cell.
Many hp's equals lots of watts which heats the water - often can be seen steaming profusely in the background.

[onecamohv]

good series Graham, thanks for going through it.

im very surprised that you had to retard the cam - what is the cranking pressure? was advancing the cam causing too high cylinder pressure leading to det? i would have thought without knowing the inner details the torque would have both went up earlier, a bit more, and held on longer with an advanced RL31, and maybe sacrificed a bit of top end bhp, but if closing the inlet at that point is causing too much cylinder pressure at peak torque with the cam advanced.....
a tighter squish would have helped this also i think... you didnt mention if you tried to advance the cam and what happened.. did you give it a go? i guess the carbs are not helping this either

thanks for the videos!

[Graham]

Graham,

what is happening here? (see black circle in photo)
Looks like (hot) coolant.

its not coolant as such although the same water does keep the engine cool via a heat exchanger. The dyno is a water brake. The engine is braked by varying the amount of water that is allowed to exit the absorber, as the revs go up and the torque from the engine drops more water flows out the absorber, it it opens quickly it takes the scavenge pump a while to catch up. so you will see the water level keep changing.

[Graham]

good series Graham, thanks for going through it.

im very surprised that you had to retard the cam - what is the cranking pressure? was advancing the cam causing too high cylinder pressure leading to det? i would have thought without knowing the inner details the torque would have both went up earlier, a bit more, and held on longer with an advanced RL31, and maybe sacrificed a bit of top end bhp, but if closing the inlet at that point is causing too much cylinder pressure at peak torque with the cam advanced.....
a tighter squish would have helped this also i think... you didnt mention if you tried to advance the cam and what happened.. did you give it a go? i guess the carbs are not helping this either

thanks for the videos!

i usually start by retarding the cam, usually thats how you get more power, if i retard it a bit and power drops i will try advancing it, but if you retard it and gain power no point in trying to advance it, unless your purely looking fo rlow end grunt.

cranking pressure was about 190psi, so in the sensible range.

squish is a funny thing, everyone says you need loads of tight swish, but some engines have none and still work well. This engine has a little under 0.050. with really tight squish you can be in the position that the burn speed is so high you actually have to start retarding the timing. i think it pays to get tight on high rpm/race stuff.

i think with 45's carbs or ITB's longer straighter intake trumpets would of given more top end power. but this never really was about maximising power

[FrankC]

Another informative video Graham. Look forward to hearing what the customer thinks once it’s back in the car.
If my std pinto needs a bottom end refresh and a little work on the head I’ll know who to get in touch with…

[madmaxptt]

Great video and info, great test as always! I’d like to see the same setup on twin 45s with 38&40mm chokes!
long & short intake manifold and different length trumpets!