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Discussion Starter · #41 ·
You said ITBs help power production at low RPM. Which is nonsensical. There’s nothing inherent in an ITB setup you can not replicate in a single throttle plenum for low RPM conditions.

Now if you meant upper RPM power production, I already proved that’s not necessarily the case.

ITBs give you an infinite plenum volume (when run open and chewing up FOD), and a very low volume behind the throttle plate. This makes pressure changes a small amount quicker behind the throttle blade on a large throttle angle transient. Beyond that, it’s just an intake runner with a throttle blade in the middle. Nothing inherently magical about it, but people have many misconceptions about what power improvement they will give to an engine.
 

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I have a 2GRFE with ITB's. In comparison to the single, I found it superior with throttle control over the standard single. It is really chalk and cheese. The car had way more control in balancing the car for the corner, mid corner control and exit off the corner. Car was over 2 seconds a lap quicker on a 2.2km road course than an equally powerful 3SGTE within a few sessions on very old worn tyres.
The negative is the R&D, finding someone to put it together that will get it right. It was not cheap but no billet ITB set-up ever will be. If I was to do it again, I would start the build from the intermediate section of the intake set up, set the throttle bodies lower to reduce the throttle size a little then keep the trumpets a bit smaller for quicker flow.
I can't really say much about the stroker engine but have worked out a few things with the engine Mine has 295 degree cams with 11.8mm lift. The standard lifters have not been able to hold up to the combination but have found a solution by using Ford Mustang GT350 hydraulic lifters to replace the standard lifter. They are not cheap, but do manage 305 degree/13mm lift cams on 8200rpm race engines over here in Australia.
I am also moving the Mustang beehive spring mated to 2UZFE titanium inlet valves. Valve springs require a small amount of machining to fit but nothing dramatic.
The problem (I believe) you will have with a 9000rpm engine is oil surge in the oil pump and lifter pump up. I don't know if the Coyote will solve this but I am not willing to push this (soon to be rebuilt) engine to that level to find out.My rpm will be 8000rpm.


76555

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@B24nsw 295 is a lot of cam. Did you run these with the single throttle setup too? What is the lowest rpm that you are able to set the idle speed at?
 

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Did some more digging, looks like Honda F20B (JDM only engine I think) rods work. 145 mm rod length, which gives an 88 mm stroke vs. 83 mm stock stroke. Rod big end dia is down to 48 mm, and crank rod journal dia goes from 53 mm stock to 45 mm. Lots of meat to regrind only a 2.5 mm centerline change, but less journal overlap. I wouldn't think bearing pressure would be problematic at our RPM, but I dunno, a 2GR piston weighs a lot more than the 85 mm bore F20B piston. Final displacement would be 3664 cc, so only a small bump. Based on that, probably not worth doing unless you were looking at getting that final bit out of the engine.
I'm interested in re-visiting this, in combination with a sleeved block bored for 97mm pistons - that give 3.68L witih the stock crank and rods. Going this route would up the budget but it could get to a nice number for displacement. Could I impose on you to make a calculation of the displacement that is achievable when you combine offset grinding the crank (as you outlined above) with the larger bore? That would be a big help. Pistons would be the forged aluminum wiseco 97mm, that I don't have a weight spec, but can find one probably.

PS.If I make a simple-minded calculation assuming the displacement is increased proportionately regardless of the bore, I go:
Displacement = 3680 x (3664/3450) = 3908.

If that's right it's, 13.3% jump from stock displacement. This would be a nice "low-budget" enhancement to a bored block.
 

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@B24nsw 295 is a lot of cam. Did you run these with the single throttle setup too? What is the lowest rpm that you are able to set the idle speed at?
Yes I guess it is pretty aggressive but thats what they came up with based on all the information I gave them. Its not a street car, just road course. I have only run it with the ITB. Idle speed is 900rpm.
 

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I am also moving the Mustang beehive spring mated to 2UZFE titanium inlet valves.
I have MWR springs on my car. These have been getting bad press lately for being "too stiff?" Aside from these, Kelford Cams lists a spring and retainer set for 2GR-FE, but they do not list any other items (i.e. camshafts) for this engine.


Kelford does give a spec for these springs. I don't have a spec handy for MWR springs to compare.
 

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The standard lifters have not been able to hold up to the combination but have found a solution by using Ford Mustang GT350 hydraulic lifters to replace the standard lifter. They are not cheap, but do manage 305 degree/13mm lift cams on 8200rpm race engines over here in Australia.
Would a solid lifter solve these issues? Assuming that a direct fit solid lifter could be found. People have talked about the Ecotec lifter for ages - but these require a lot of ancillary machining to fit.
 

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The problem (I believe) you will have with a 9000rpm engine is oil surge in the oil pump and lifter pump up. I don't know if the Coyote will solve this but I am not willing to push this (soon to be rebuilt) engine to that level to find out.My rpm will be 8000rpm.
With solid lifters, what are your thoughts on oiling - are there any other limitations to consider, besides the lifters. Not too concerned about high-G starvation, just wanting to drive in a straight line.
 

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Lexus IS-F titanium valves are a known direct fit. According to MWR, intake weight is 30.2g vs 52.3g stock (42% lighter) Exhaust valve is the same weight so I don't see any real reason to spend money on those. Oversize valves could be nice if found, but worry about interference valve-to-valve and valve-to-piston with higher duration cams and/or higher compression ratio pistons.

 

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I have MWR springs on my car. These have been getting bad press lately for being "too stiff?" Aside from these, Kelford Cams lists a spring and retainer set for 2GR-FE, but they do not list any other items (i.e. camshafts) for this engine.


Kelford does give a spec for these springs. I don't have a spec handy for MWR springs to compare. I would have to go watch a video where someone mentions it in passing.
 

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Discussion Starter · #52 ·
I'm interested in re-visiting this, in combination with a sleeved block bored for 97mm pistons - that give 3.68L witih the stock crank and rods. Going this route would up the budget but it could get to a nice number for displacement. Could I impose on you to make a calculation of the displacement that is achievable when you combine offset grinding the crank (as you outlined above) with the larger bore? That would be a big help. Pistons would be the forged aluminum wiseco 97mm, that I don't have a weight spec, but can find one probably.

PS.If I make a simple-minded calculation assuming the displacement is increased proportionately regardless of the bore, I go:
Displacement = 3680 x (3664/3450) = 3908.

If that's right it's, 13.3% jump from stock displacement. This would be a nice "low-budget" enhancement to a bored block.

Easy enough to do yourself.

Stock crank and 97 mm bore gives 3680 cc, and if you could get another 3 mm of stroke for 86 mm stroke, you'd get 3813 cc. I will say I'm not a huge fan of sleeving an engine - it takes a ton of rigidity out of the block, and can cause some long term reliability problems as a result (bearing wear, potential head sealing).

The 1GR crank would probably be best for an all out NA engine, but I do wonder what the rod/stroke ratio would start to look like. Probably not good, so it might not make great power above 6-7k RPM.
 

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Discussion Starter · #53 ·
Lexus IS-F titanium valves are a known direct fit. According to MWR, intake weight is 30.2g vs 52.3g stock (42% lighter) Exhaust valve is the same weight so I don't see any real reason to spend money on those. Oversize valves could be nice if found, but worry about interference valve-to-valve and valve-to-piston with higher duration cams and/or higher compression ratio pistons.

Is that the p/n for the titanium valves? That's super cheap for an OEM titanium valve...
 

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Easy enough to do yourself.

Stock crank and 97 mm bore gives 3680 cc, and if you could get another 3 mm of stroke for 86 mm stroke, you'd get 3813 cc. I will say I'm not a huge fan of sleeving an engine - it takes a ton of rigidity out of the block, and can cause some long term reliability problems as a result (bearing wear, potential head sealing).

The 1GR crank would probably be best for an all out NA engine, but I do wonder what the rod/stroke ratio would start to look like. Probably not good, so it might not make great power above 6-7k RPM.
Thanks for the reply. My simple-minded calculation was very close. With the calculator your linked, for 88mm stroke, I get 3901cc, versus 3908 that I estimated.

With all the mods requried, I'm not that certain that I can pull off a 1GR crank swap. A offset grind on the 2GR crank seems like the easier path. It's understood the crank will be weaker. Besides I don't have a 1GR crank.

With a 88mm stroke (vs 83 stock) and 145mm rod (vs 147.5 stock) the rod/stroke ratio is 1.65, compared to 1.78 stock. 1.65 does not seem like it woud be too limiting.

The tough part of this is figuring out the compression ratio - too many unkowns, including piston volume, head gasket thickness (stock is known 0.5mm according to MWR but Cometic for 97mm bore is different), and head volume. I would be shooting for 12:1 at the minimum. Another open question that affects this is whether to bore the heads to match the cylinder bore, versus leave as is. MWR sells 12:1 and 13.2:1 pistons with 97mm bore but I don't know what factors (HG thickness, head cc) enter into their calcuation.
 

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Discussion Starter · #55 ·
Aftermarket pistons usually specify the piston dish, it might be worthwhile buying a used 2GR-FE stock piston to measure the dish yourself, then you can back calculate stock combustion chamber volume + HG thickness.

I wouldn't touch the combustion chambers personally. I've seen more engine builds get messed up by SOMETHING being off in the head machining than anything else when you start doing valve jobs etc. Common one is having the valve installed height be all off or the guide and seat not be perfectly concentric and perpendicular.

While I'm sure the 2GR-FE would pick up some power in an all out build with tweaking the valve sizes, I feel that'd be a pretty risky proposition.


I'm kinda curious what an offset ground 2GR-FE crank + stock pistons would do. Should be a very reasonable compression bump for pump gas, ~11.4-11.5:1.
 

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Great input. Thanks.

I need extra displacement from bored block (plus other improvements) to get to the goal I want. Long term reliability is not a consideration.

It appears 2GR power peaks and drops off relatively early regardless of the cam (stock, Stage 1, Stage 2) or tune (stock ECU or standalone). This is confirmed on multiple dyno plots. Not sure what inherent limitaiton causes this.

Maybe can be done with the valves. I think I can source direct fit +0.5 or +1mm valves that leave the seat and guide the same other than muti-angle valve job. I'm aware of the risks. Will need some measurements on the spare heads I have in the shop.But looking at this hi-res pic (1600x1200) there is not a lot of extra space available.

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It appears 2GR power peaks and drops off relatively early regardless of the cam (stock, Stage 1, Stage 2) or tune (stock ECU or standalone). This is confirmed on multiple dyno plots. Not sure what inherent limitaiton causes this.
While this may be true, as you yourself pointed out one would still want to rev to 8k+ (even on stock cams) given the readily available transmission options. And getting any of the (manual) transmissions to shift well at 8k+ can be a challenge. Do you really want to extend the power band even higher? Could be a non issue if you have plans for some sort of automatic or dog box, but it seems worth a thought.
 

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Discussion Starter · #58 ·
Head work is key to making big NA power. A slightly larger valve can help, but keep in mind it can quickly spiral into extra capacity if you can get the stock valve seat to work.

Keep in mind the larger bore helps port flow by helping deshroud the outer part of each valve. So there is extra flow just going to a slightly larger bore.


Even the MWR Stage 2 cams seem pretty tame to me. If I were going to go through the expense of sleeves, head work etc, I’d definitely get custom cams machined up with a very aggressive profile. I think there’s more power in a really aggressive, not reground cam profile than a small displacement bump sleeving will give you.
 

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While this may be true, as you yourself pointed out one would still want to rev to 8k+ (even on stock cams) given the readily available transmission options. And getting any of the (manual) transmissions to shift well at 8k+ can be a challenge. Do you really want to extend the power band even higher? Could be a non issue if you have plans for some sort of automatic or dog box, but it seems worth a thought.
I myself see two separate questions to address.

1. Would there be an advantage to higher output above the current peak at/near 7K rpm or so? Answer yes, definitely. It should be obvioius that if you are revving in that range then more output makes the car faster, even with a 8K rev limit.

2. What the heck is the deal with the 8K limit on the e153. Lots of contradictory info on this one. Some builds report shifting without problem at 9k. Others start having issues as low as 6.5K. It has been suggested that this could a clutching issue rather than a internal trans issue. I myself have no problem shifting at 8K. Just lucky, I guess? If I did not have some reservations about taking my hydraulic lash adjusters aka lifters above 8K, then I would try upping the rev limit to see what happens. With solid lifters I would not have this fear of spitting. Solid lifters along with oversize valves are on the goodies wish list.
 

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Head work is key to making big NA power. A slightly larger valve can help, but keep in mind it can quickly spiral into extra capacity if you can get the stock valve seat to work.

Keep in mind the larger bore helps port flow by helping deshroud the outer part of each valve. So there is extra flow just going to a slightly larger bore.


Even the MWR Stage 2 cams seem pretty tame to me. If I were going to go through the expense of sleeves, head work etc, I’d definitely get custom cams machined up with a very aggressive profile. I think there’s more power in a really aggressive, not reground cam profile than a small displacement bump sleeving will give you.
I'm not sure if I am getting the meaning of this: "it can quickly spiral into extra capacity if you can get the stock valve seat to work."

I see a lot of online debate about larger valves, do they help, do they hurt (by reducing port velocity), are they just plain useless.

Re the cams there is a new billet cam offering from Piper. "Fast" cam with 270 duration, "Ultimate" cam with 285 duration. I don't know how these are measured. Compare to 256/266/272 for MWR Stage 1/2/3. Again, I don't know how these are measured, i.e. at what clearance. It could be that Piper and MWR are measured at the same clearance - or not.

Another possibility for a budget build is to adapt a high-duration cam from a 2gr-fks. The simulated Atkinson cycle requires much higher duration cams, but I don't have their spec. . Someone is taking this approach with the 2AR. PS. I have just been informed this can be scratched off the list, it is a no-go, because of different camshaft construction.
 
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