I need to rebuild the 2f engine in my 83 FJ60. I want to install new pistons that have a higher compression ratio than stock. Any suggestions as to a parts supplier or piston manufacturer. Is it possible to buy a piston that will get the compression to 9 to 1? I know that Man-a-fre has a very expensive high compression slug, are there other options?
Higher Compression (1 Viewer)
- Thread starter FJ60FOOL
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pistons don't raise compression... camshafts do. The high compression pistons you see are "rating" which means those pistons will last longer in an engine with high compression cam.
I've always been a fan of MAF... they do good by their customers and have fair prices. I'd contact Steve-O (from MAF) either on this board or call him for help. He'll tell you exactly what you need and give tech advice on getting it installed.
My $.02
I've always been a fan of MAF... they do good by their customers and have fair prices. I'd contact Steve-O (from MAF) either on this board or call him for help. He'll tell you exactly what you need and give tech advice on getting it installed.
My $.02
Mark W
Yep, I really don't really care that much I guess.
Huh??? Camshafts don't raise compression. Not by any appreciable amount. Compression ratio is primarily based on the swept volume of the cylinder and the size of the combustion chamber.
A piston that protrudes further into the chamber will reduce the usable volume and raise compression ratio. Cutting the head (or the block) shorter will reduce the usable volume as well and raise the compression ratio.
IF you were to install a shorter duration camshaft, under some narrow operation conditions it could raise the actual dynamic compression by a very small amount. Raising the duration can also raise the dynamic compression under equally narrow, but different conditions. Again, by a very small amount. Neither of these make enough difference to be concerned with except when finessing the final dregs out of a very built engine. Different duration shafts in the same engine will bring a lot more and a lot larger considerations than any change in compression that they *might* induce.
As to the initial question. I have to assume that MAF can tell you exactly what sort of compression their pistons will produce. Personally I normally swap heads or mill the head for increased compression. 9:1 -9.5:1 is doable this way.
Mark...
A piston that protrudes further into the chamber will reduce the usable volume and raise compression ratio. Cutting the head (or the block) shorter will reduce the usable volume as well and raise the compression ratio.
IF you were to install a shorter duration camshaft, under some narrow operation conditions it could raise the actual dynamic compression by a very small amount. Raising the duration can also raise the dynamic compression under equally narrow, but different conditions. Again, by a very small amount. Neither of these make enough difference to be concerned with except when finessing the final dregs out of a very built engine. Different duration shafts in the same engine will bring a lot more and a lot larger considerations than any change in compression that they *might* induce.
As to the initial question. I have to assume that MAF can tell you exactly what sort of compression their pistons will produce. Personally I normally swap heads or mill the head for increased compression. 9:1 -9.5:1 is doable this way.
Mark...
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Dude, that has to be the most uninformed post I've ever seen on the internet! Holy**** don't ever give engine advice ever ever againmiletwo said:
Mark W - i know you have built several engines with pretty impressive performance (for a 2f). what would your standard setup be? We all know the 2f isn't a power house, but i think there should be some untapped potential.
any info is appreciated.
the cam comment - give the guy a break. Some sales guy likely told him that and he is just repeating what he thought to be good info. After all - just trying to help.
I know i have said the wrong thing several times believing it to be true...
anyway - good luck
rob
any info is appreciated.
the cam comment - give the guy a break. Some sales guy likely told him that and he is just repeating what he thought to be good info. After all - just trying to help.
I know i have said the wrong thing several times believing it to be true...
anyway - good luck
rob
Mark W
Yep, I really don't really care that much I guess.
This has actually been discussed to death in various threads here. The ideal 2F would be a late model to start with. Cut the head and maybe the block deck to get the nominal compression ratio up to about 9.5:1. Run a cam in the 211-214 degree duration range (at .050 lift. This will usually be about .440-.450 inches of valve lift. Three angle valve grind can't hurt. Run flattop pistons and the original late model rods, weight match to within a gram. Dynamic balance the whole rotating assembly. Top it with an offy C series intake and an Edelbrock 500 CFM carb. (Unless you've got the motivation to build an MPI system... maybe a turbo too...) The large runner Toyota intake with a properly set up late model factory carb works well too. Run a header (I don't care what style or brand) 2.5 inch exhaust with a free flowing muffler. Late model electronic ignition is good (recurve the advance). Mallory makes (or made at least) a nice electric ignition distributor with or without vacuum advance. This works nicely with an MSD ignition system which allows for variable timing control as well.
Keep the oil cooler. Tweak the oil pump for a bit more pressure/volume. Stick with the factory clutch fan. OEM clutch or aftermarket version of the original works fine.
It won't match a hotrod V8. But I doubt that you'll ever feel underpowered in the least. And it'll get better fuel economy that stock if driven for economy. It'll run on regular (be a bit happier with premium... at todays prices premium is only about 6-7% more than regular around here). And it'll still last for an easy 200,000 If you treat it halfway right it could go 400,000 just as easily.
Mark...
Keep the oil cooler. Tweak the oil pump for a bit more pressure/volume. Stick with the factory clutch fan. OEM clutch or aftermarket version of the original works fine.
It won't match a hotrod V8. But I doubt that you'll ever feel underpowered in the least. And it'll get better fuel economy that stock if driven for economy. It'll run on regular (be a bit happier with premium... at todays prices premium is only about 6-7% more than regular around here). And it'll still last for an easy 200,000 If you treat it halfway right it could go 400,000 just as easily.
Mark...
Thanks Mark!
the cam - will this mess with emissions? I saw some threads regarding the RV cam, but i thought they increased the amt of pollutants output.
way off? WA is a bitch to get to pass already...
Thanks!
rob
the cam - will this mess with emissions? I saw some threads regarding the RV cam, but i thought they increased the amt of pollutants output.
way off? WA is a bitch to get to pass already...
Thanks!
rob
flat top pistons? the original ones in my 87 aren't? Sorry, but just not familiar with the differences in the 2f engines through the years... or much else really. lol
rob
rob
Why only 9.5:1, seems alittle low for an N/A engine? I run 12.1:1 static compression ratio on my honda, I'm not even sure what the dynamic copmression ratio is @ 8400rpms.... I mean if your going to run fuel injection and you can maintain a nice 13.5:1 Air fuel ratio though out the rpm band you should be fine with compression ratio's of up to 11.5:1 in a non turbo application...Mark W said:
thanks Mace.
anybody have info on the cam and emissions?
relix - i am not sure how much honda stuff you can apply to an old tractor motor... It's not lightweight or aluminum or quick revving or capable of 8500rpms...hehehe
low n slow! but sure as hell better looking.
hehehe
rob
anybody have info on the cam and emissions?
relix - i am not sure how much honda stuff you can apply to an old tractor motor... It's not lightweight or aluminum or quick revving or capable of 8500rpms...hehehe
low n slow! but sure as hell better looking.
hehehe
rob
Mark W
Yep, I really don't really care that much I guess.
For an old school motor like a 2F anything over 10:1 is going to call for octane booster with todays gasoline.
Knock sensors are tough to run in a non-overhard cam/solid lifter enginbe. Without knock sensors you really can't run an EFI that has the capability to reduce timing when detonation rears it's ugly head.
Now, tell me again that you want to run 12.5:1 in your 2F on 92 octane premium.
Mark...
Knock sensors are tough to run in a non-overhard cam/solid lifter enginbe. Without knock sensors you really can't run an EFI that has the capability to reduce timing when detonation rears it's ugly head.
Now, tell me again that you want to run 12.5:1 in your 2F on 92 octane premium.
Mark...
Mark W
Yep, I really don't really care that much I guess.
I have run cams like this in stock and almost stock engines. I can get them past emissions with under 10% of the allowable limts for hydro carbons and CO at idle and at 2500 (no load. We don't text for NO here and don't have dyno testing either so I have no way to know what that would look like. Probably just fine as well.
Mark...
Mark...
I never said anything about 12.5:1 compression Ratio in a 2F....... As far as not having a knock sensor my 1994 B18c(JDM Integra Type-R engine) has no knock sensor also..Mark W said:For an old school motor like a 2F anything over 10:1 is going to call for octane booster with todays gasoline.
Knock sensors are tough to run in a non-overhard cam/solid lifter enginbe. Without knock sensors you really can't run an EFI that has the capability to reduce timing when detonation rears it's ugly head.
Now, tell me again that you want to run 12.5:1 in your 2F on 92 octane premium.
Mark...
But then again I've never done anything to a 2F engine so I guess I'm not the guy who should be giving any advice on the subject....
Although I will be converting one or both my Landcruiser 2f(87 fj60/77 fj40) to either MPI or TBI here in the next few months....After that I'll see if I feel i need some higher compression slugs in there... BTW who makes cams for these engines?
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Time for todays engine math lesson.FJ60FOOL said:
Stock engine:
bore is 94mm
swept volume 4230cc
chamber volume 579cc
CR is 8.3:1
Bore engine 1mm OS:
95mm bore
swept volume 4320cc
chamber volume 579cc
CR is 8.5:1
bore 1.5mm OS:
95.5mm bore
swept volume 4367cc
chamber volume 579cc
CR is 8.6:1
So, just by going to 1.5MM OS pistons, displacement increases by 137cc and CR goes to 8.6:1.
Tomorrow we can quantify the effects of milling the head.
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Jim - I always look forward to your posts.
im stumped. if the diameter of the bore increases from 94 to 95.5 - how does the chamber volume stay the same 510cc's. a larger piston unless going further "up" would have to have a larger combustion chamber right? ah wait super small fraction larger in the chamber, but along the entire swept length...
crap just think i figured it out...
am i close?
rob
im stumped. if the diameter of the bore increases from 94 to 95.5 - how does the chamber volume stay the same 510cc's. a larger piston unless going further "up" would have to have a larger combustion chamber right? ah wait super small fraction larger in the chamber, but along the entire swept length...
crap just think i figured it out...
am i close?
rob
Mark W
Yep, I really don't really care that much I guess.
Nope. The combustion chamber is in the head. You do not increase it at all when you increase the diameter of the cylinder (in the block). The piston moves upwards and crams the contents of the cylinder into the combustion chamber. Larger volume into unchanged volume.
Mark...
Mark...
lol
thanks mark - that makes sense.
Just so long as someone doesn't make fun of my ignorance and tell me i am not allowed to have any input on another engine thread...hehehe.
enough jibber jabbin' - night all.
rob
thanks mark - that makes sense.
Just so long as someone doesn't make fun of my ignorance and tell me i am not allowed to have any input on another engine thread...hehehe.
enough jibber jabbin' - night all.
rob
You're talking about me?sl33py said:
