true...was thinking 0.5mm was minimum ..stick with 10.5:1 and build the 1700...you have all the parts...and if it doesnt perform then look at building the 2.0....
Mark
true...was thinking 0.5mm was minimum ..stick with 10.5:1 and build the 1700...you have all the parts...and if it doesnt perform then look at building the 2.0....
Mark
Yes 10.5 is with the pistons flush with the deck. I'm using a Victor Reinz gasket - would this allow for a 0.5mm skim? as this would give me another 3cc approx. making it 35cc and 11.2 to 1 CR
Cheers Chris.
Hang on - no it wouldn't, as I'm calculating the the volume of the gasket as if it's 1mm thick. Aren't they about 1.3mm compressed? This would only bring it up to 10.7 ish.
Last edited by MemphisTwin; 23-04-2014 at 14:14.
Victor reins last time I checked was 55 thou, so yeah about 1.3mm, you can skim the block half a mm and have the pistons out the bore 20 thou giving you a safe 0.8mm piston to head clearance.
btw great build thread, been watching this with anticipation since the start.
its not dead till it's buried!
T.I.T engineering. "Feel the power!"
Why don`t you do like I am, Pistons 10 Thou out of the Bore and use a Cometic MLS Gasket at 40 Thou thick compressed. My calculations with that give you 10.63. 1. I still have the RL 31 you can borrow for set up purposes if you want. You need a bit more than a FR cam in my opinion, otherwise all that Head work has been pointless.
Cheers for that. I've already got the gasket, so I'll just get the block decked 0.5mm. It's not looking too bad now - I would much rather build the 1700 than a 2.0L. I suppose just looking at the static CR doesn't give the whole picture as I expect cylinder filling to be better than conventionally ported heads, hence higher compression. Bloody hope so anyway!
Not too much to report, but everyone likes photos!
I did a dummy build of the short engine to check the fitted piston height. I knew in theory what it should have been, but it's nice to know that I can still add up. Pistons protrude higher than the deck height by 0.002", so pretty much flush really, and exactly where I thought they'd be. Crankshaft spins effortlessly on the new competition bearings, which is a great relief.
Plenty of clearance for the Cosworth YB Rods
So I reckon that I need 0.5mm off the block to gain some compression, yet still leave 0.8mm safety margin between the head and the pistons when using a Vic Reinz gasket compressed to 1.3mm.
OK I admit it; this isn't going to work.
With the valve pockets required for the skimmed downdraught head and any decent competition camshaft, I'm just not going to have any compression. The head would work well on a 2.0l+ bottom end, but on the 1700 it's no good. Back to the drawing board.
To be honest, this is really pissing me off. I think I'll leave it for a while....
Last edited by MemphisTwin; 07-05-2014 at 12:34.
Gutted for you mate..trying to work an answer...im no expert ....but one option i can see is raised top pistons,and a cam with 2-3mm at tdc...i dont no what sort of cam is needed for hill climbes ...but if you could use a more torqey cam with an earlier inlet closing angle 60-65...it would increase the dynamic compresion ratio...
mark...
also thinking raised top pistons, speak to freddie686868 ( think thats his username) he got a custom set of domed pistons made for not a lot of money.
its not dead till it's buried!
T.I.T engineering. "Feel the power!"
here's a link to my forged engine build
http://www.turbosport.co.uk/showthre...=276802&page=6
Have you looked into what overlap the RL 31 Cam has at TDC? There must be one somewhere that `ll do the job!
I'm sorry for everyone that's been following this thread, but I just can't get it to work how I wanted.
With the required piston pockets, I'm looking at a compression ratio of less than 10 to 1. I could prepare another 1600 head with smaller valves and less unshrouding to do (which lowers the CR) but I just can't summon up the enthusiasm at the moment, and I'm very keen to use my downdraught head to see how it goes. So unfortunately the 1700 is shelved for the time being.
So bollocks to it! It's now going to be a 2.1 litre. In a 500kg car It'll be even more of a flying machine.
Yesterday I picked up a 2.0l block and crankshaft. The crank had been reground to 0.25mm undersize on mains and big ends, but unfortunately it had suffered some condensation damage and may need a regrind to -0.5mm. I t-cut the journals to clean them up, but there are some stubborn little pits here and there (probably no more than one thou deep). I'll get it to the machinist and see what they think.
Now the block. It's already at 93mm, and has just been honed. There's no wear or lip in the bores, but it does have a few score marks. They're not deep but you can feel 'em. When I carried the block from the car, I commented that it was the heaviest ruddy Pinto block that I've ever picked up (!) which made me very curious. It's a 205 block with 2222 stamped on the distributor mounting boss, and it has YBB7209 stamped near the water pump. I think it may be an early Cosworth YB block...anyone know? I know sod-all about Pintos!
I measured the bore walls, and even at 93mm they are still between 5 and 6mm thick. I believe this is plenty to go to 94mm, as they would still be 4.5mm to 5.5mm thick. If that's the case, I could build a 2136 engine and even with deep valve cut-outs in the pistons I would still have over 12 to 1 CR. Much more like it.
So the question is; would this block be OK at 94mm? Anyone?
Cheers Chris.
A week is a long time in the mind of an amateur engine builder! One thing for sure is that "I'll never hang myself".
So...I haven't given up on the 1700, but have given up on the 2.1. My heart just isn't in it.
The problem with the 1700 is that I had two different projects going on hopefully to come together in the same engine. The first was to build a short stroke/large bore 1700 screamer of an engine; the second was to develop an experimental downdraught cylinder head. Well I've now got a very nice bullet proof 1700 bottom end with long YB rods, short 66mm stroke and 90mm forged pistons. I've also got a rather fine downdraught cylinder head with 45.5 inlets and 38mm exhaust valves. Problem is...they don't go together! Even with a 2.5mm head shave, I just don't have enough compression.
So I'm on the lookout for a 1600GT head with the 42mm inlets as standard. I'll take them out to 44mm and maybe go up to 36mm on the exhausts (which is plenty) and therefore won't need so much unshrouding (and loss of compression) I will then have the chambers welded to increase the CR so I don't have to shave the head. I will probably do a conventional porting job with port-floor epoxy filler. From results I have seen here on this very forum , the head should flow extremely well. Anyone got an early 1600 GT head?
There's no real rush on this project now as I have ( rather ashamed to say ) also acquired a XFlow engine which I will also be building into a 1700 hillclimb screamer. I know much more about Xflows than Pintos, having built several in the past, and TBH I really like their simplicity and compact dimensions. Of course I do have a few ideas to incorporate into this engine. I will use a standard crankshaft but forged pistons and long rods, a top notch head - I may do my own or I may bite the bullet and get that CNC Alloy jobbie, and I intend using titanium pushrods and valve spring retainers from the USA, which with the the dollar very low against the pound at the moment, is a much less expensive proposition than it sounds. I can get the XFlow up and running quite quickly, so I can get out and do some events asap...and then finish the Pinto at my leisure; I've gone too far to drop it now. Then it would be nice to get them both on a dyno and compare the two.
Cheers Chris.
OK, so I've just sold my last remaining kidney and bought one of these:-
http://www.cncheads.co.uk/?p=727
It really is a stunning piece of kit, and there is no way I would dispute those flow figures. Nearly 121 cfm @10"H2O at 0.5" lift from a Xflow! To put that into perspective, I've been reading about the Dave Walker/RetroFord magazine ultimate 2.4l Pinto. Their head (with no added material) flowed 122cfm with inlet valves 4mm bigger.
Cant wait to get this engine together.
Anyone want a 1700 Pinto short engine?
Last edited by MemphisTwin; 12-06-2014 at 16:26.
cool mate..good to see you up and running again.....nice head ..will be watching.....
Go for the X/flow !
Well 5 years has flown by, and I'm beginning to look at this 1700 Pinto once more. It seems such a shame to waste this strong 1700 bottom end after all that work. I've managed to get a 1300 Pinto head and now I'm looking forward to getting out the die grinder!
I have still have n't done anthing yet with the 1600 head I bought off you Memphis. After having it flow bench tested I dummy fitted various cams including a WR40, BF63 and a Lulabelle to see what clearance there would be without pocketing pistons. My conclusion was only the LB would require the pistons modifying. At the moment the head is gathering dust and probably rust.
Keep us all informed on how you get on as your last build was explained in such fine detail. Are you going High Port once again.
The tragic irony of all this is that it took me ages to find a 1300 casting, and now I know where there at least 6 others. I've also found an engine builder who welds Pinto chambers to increase compression, amongst other "demon tweaks". Had I known this 5 years ago, things would have been much different. Oh well..
I'm going to keep the ports of this head on the smallish side, and make them D shaped. I want to keep the gas speed high. I've also been thinking of using readily available pinto valves, and using lash-caps to get the required length for correct geometry. Would lash caps be a problem for a high revving engine?
If you can find them lash caps are ok, but I think outside Sommint racing in the USA you won’t find any. Alternatively just use Essex V6 valves they are longer than 1600 pinto ideal for a 1300 head
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Good To see you got it going again!
Ford Taunus Going RS2300 16v with 48s!!!
There's nothing like a Pinto to make people prick their ears up.
I started porting the 1300 head casting. My god it needs some metal grinding out!
I've just about finished the inlet ports and taken them out to 37mm round (at the moment). I've finished the valve throats, and am going for a 44.5mm valve. Chambers need quite some valve unshrouding. I don't want to go too big on the exhaust valve, but there isn't much available at 115mm length so will probably go with 37mm 1600 length (113mm) and use 2mm lash caps; aircooled VW ones fit as luck would have it. Trouble is that I would have to machine 2mm on the spring seat to fit them and get the right valve spring fitted length (which is rather a lot). The smallest competition Essex V6 exhaust valve is 41mm; WAY too big. Pistons will need valve cutouts almost certainly as the chamber depth will be only >5mm.
But there's another spanner in the works...!!
I've also now got a very nice early 1600 head casting. It requires nowhere near the amount of metal removing as the 1300; valves are easier to source in the right size and length, and spring seats shouldn't need machining, and nor should the pistons. I've found several places who are experts in cast iron welding on cylinder heads, so the option is there to weld up the chambers to get higher compression, which is something I couldn't do on the downdraught head I made a few years ago due to the glued in inlet tubes. I'm beginning to think that the 1600 head with welded chambers would be would be a better option. I'm going to mull it over for a day or two and report back; hopefully with pictures!
Cheers Chris
not quote sure how you would use vw lash caps anyway, unless narrowed on top the wouldnt fit the pinto follower
Oh bollocks! I hadn't thought of that... I really don't want to use a standard Ford Essex 37mm exhaust valve on the 1300 head as I intend it to be quite high revving, and by all accounts are heavy and unreliable for high rpm.
The welded 1600 head is definitely looking more attractive now.
There are people that say a 36mm exhaust valve is adequate for a 2.0 Pinto so maybe for a 1700 they would be okay, just a thought.
If you have gone to some much work porting the head then it's a shame not to use it.
Last edited by Forest_rallying; 26-10-2019 at 08:01.
Are you going to deck the block ...
It's not the diameter of the valve that I'm worried about, it's whether a standard Ford valve would stand regular use North of 8000rpm. I'm still a novice when it comes to Pintos.
Well....that didn't go to plan. I managed to grind through one of the inlet ports of my 1300 head. All is not lost though; I could sleeve the ports with glued in tubes, or just go to 1600 head and get the chambers welded.
It wouldn't be an easy weld and all the ports are very thin. I was being greedy and just went too far. It would actually now be easier to turn it into a downdraught head along the same lines as the other one (yours!).
I'm still left with the problem of the long exhaust valve though
I don't want go over 37mm and it needs to be about 115mm length. Standard Essex exhaust valves are exactly the right size , but I just don't know if they would be reliable.
Why not have a word with Paul Ivey at REC if he's still on the go regarding valves.
So I can say categorically that 1300 inlet ports have much thinner walls than a 1600 or 2.0. I'm going to persevere with the 1300 but the ports will need sleeving. And if they need boring uniformally to get a sleeve in there, I may as well go the whole hog and make the sleeves downdraught. The other downdraught head I did flowed 117cfm at 0.5" lift with only a 34.8mm diameter port, and I'm sure if I'd used a slighted larger dia. tube the flow would have been quite a bit higher. Just a 2mm larger bore gives nearly a 12% increase in cross sectional area. If the port was restricting flow, the slightly larger new port has gotta help.
But just in case it doesn't work for whatever reason, I have the 1600 head casting as a standby. To get the CR up on this head I could either shave it to death (2.5mm) or have the chambers welded. I've had a quote for welding the chambers from a firm that specialise in welding cast iron, but it seems very expensive to me. What would you expect to pay for reshaping the combustion chambers on a Pinto.? Does anyone know?
Cheers Chris.
I have seen one of Brookes's heads with welded chambers so you could try him for a quote but don't expect him to be cheap.
dont mean to sound negative, but that sounds a lot of work for 117 cfm, a 1600 head can do that without any radical mods
Yes you're right.
I've given up on the 1300 head for now. Poking around with a big screwdiver found fresh air in the walls of all of the inlet ports. It could possibly be saved by boring holes for downdraught tubes but I don't know if I can be bothered, or even if there's enough metal left to fix them in.
What's the most I can shave off the 1600 head to gain compression?
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