vinnyzcrx

In this thread i would like to talk about the frankenstein swap, there are good and bad aspects associated with this swap. A bad one for example is cylinder wall wear, but of course a blockguard reduces the likeleness of the engine blowing due to cylinder wall flex, but still does not eliminate clyinder wall wear which eventually leads to ovel shaped cylinder and low compression and problems. with this said one must thing about the rate at which the cylinder wall will wear, yes this swap put more pressure on the sides of the cylinder walls but is it really that much more than say a stock b16 or 18?

Good or bad swap? answer with valad responses please

Kai

You're talking about rod/stroke ratios, cylinder wall loading, and piston speed. The lower the rod/stroke ratio, the worse those problems will be... the B18A/B, B20B/Z engines get away with a 1.54:1 R/S because they were'nt designed to rev as high as their VTEC cousins. Compair to a B18C's 1.58:1, which is only slightly better. The main issue with that is spinning rod bearings, which is why they (B18C*) come from the factory with three main block girdles. This makes for a more stable high RPM engine, unlike the previous generation's B17A which is notorious for spinning rod bearings even though it has a more kind 1.62:1 R/S ratio. The B16A (1.76:1 R/S) doesn't have these problems because the rods are long enough to cut back on piston speed and cylinder wall loading.

The moral of the story: install a B18C or aftermarket block girdle if you're really concerned, along with the basic LS/VTEC reinforcements. If you are really worried, swap in a B18C rotating assembly.

Provocateur

If you are that worried about the cylinder walls wearing and flexing, get the block sleeved. It is superior in every way to a block guard.

And I agree with Kai: if you are increasing the redline of the engine, a girdle is a great idea.

j87w

On a LS (not sure if a b20 piston will clear) you can add oil squirters into the oil galleys like the vtec models, you can add ARP bolts, you can have the rotating assembly balanced, add a girdle as Kai said, ect. Golden Eagle Mfg. sells parts for Frank motors. You may want to check out what they have for you. I think as long as its built correctly (parts I said, plus some other random stuff) it can and will be just as reliable as a GSR or B16. Your going to just have to build it right and take good care of it. Just my opinon though.

Kai

Even with aftermarket sleeves, cylinder wall loading and subsiquent wear will still be a problem. Granted, it will be much better (then, for example, a B21A) but it will still create a bit of extra drag (and wear) in the engine.

BoostedITR41

If you are going to turn a frank motor above 8k rpm there will be issues with heat/friction, and wall loading. Iron sleeves will help this but won't fix it. if you want the displacment and torque you get from the LS block just get a B18c block sleeved and bored to 84mm which will give you 2L of displacment. with that you will have a block that is made to rev to and above 8k rpm and still get the big displacement

twinring

youre right blockgards will cause your pistons to become oval, which is a greater concern over cylinder wall wear. No engine I ever build will ever have a block guard in it. Block sleeving is not the end all of any of the berfore mentioned issues. Block sleeving causes severe stress to the entire block during and after the sleeving process which can open a whole new can of worms... If I were in your place Id try block posting.

BoostedITR41

Block posting is the worst idea yet. the posts are spread to far apart and the crack will actually form at the posts. on top of the fact you are putting a pin on an already weak sleeve creates stresses around that post because the only part of the sleeve being supported is the area with the post. If you put to many in you get into cooling issues get a good company to sleeve the block and you will be fine. between my friends and I there are 8 of us that run golden eagle sleeves and none have ever sank or anything else. as for the block gaurd. I ran an inline pro in my block for over 2 years with no issues and the block was still good as new when I pulled it for sleeving. even with 92k miles pistons rods bearings cylinders everything was perfect.

twinring

block posting is as old as automotive racing. If you think about what it is that a post or a block guard or sleeves are doing they are only bracing against the lateral motion of the crank. which means the major and minor thrust sides of the cranks rotation. the spacing of the posts is dead center with the cylinder bores on the front and rear of the engine on the thrust sides which means that bracing anywhere other than the thrust angles i.e. crank or flywheel side of the engine is doing nothing. the void between the posts has nothing to do with any weakness its simply all that is needed nothing more. A block guard is bracing an engine in areas that isnt even in need of bracing, and in turn causing other kinds of problems. The floating deck made by Honda was done for a very good reason, and its still used in thier highest HP 4 banger today. Ive never seen posts crack...

Now you say that everything was perfect but did you run a dial bore guage in the cylinders to see how tapered they became? I guess it didnt matter since you were going to have the block sleeved, but I wouldnt recommend using a blockguard to someone who doesnt plan on spending $1000 to sleeve thier block, because after using one of those they just might have to have thier block sleeved or like one person I met had to ditch the block and start over...

exospeed*com

First of all, I dont see the Frank swap as inferior or not worth doing in any case. Its a good combo that has been proven to handle PLENTY of HP and longevity.

Bad aspects? There are none.

"A bad one for example is cylinder wall wear, but of course a blockguard reduces the likeleness of the engine blowing due to cylinder wall flex, but still does not eliminate clyinder wall wear which eventually leads to ovel shaped cylinder and low compression and problems."
I dont know where you get this information. Cylinder wall flex can happen with any motor. Its not limited to a Frnkstn setup.
In our opinion, Blockguards are not necesarry. The stock block will handle 15psi of boost with no problems with proper tuning. If you plan on doing over 15psi, you should be SLEEVING the block already anyways.




The myth of LS/VTEC setups being bad are because of several factors.
1. Most use OLD or initially bad LS blocks to begin with. What do you expect with putting on a VTEC head on a 150K LS block that was probably pretty worn out already. and then REV it to 8K? of course, the block is old and can't handle that. No block can.

2. The other thing is that the DOHC VTEC setup requires MORE oil pressure than the reg non-vtec setup. You need to upgrade the LS block with a PROPER VTEC Oil Pump to handle the oiling needs of VTEC.

So to make it work and work well is NEW GSR Oil Pump and make sure that the block isnt bad to begin with.