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Sneed4Speed 1.7L Big Bore kit development - follow along
Here at Sneed4Speed we are developing a 1.7L big bore kit for R53. We have all heard of the notorious 1.8L big bore kits cracking blocks which is why we started from scratch. We took a R53 test block, bored it to the 1.8 liter size and cut it in half to measure the cylinder walls thickness to see if we could successfully make a bigger bore kit that would not crack the block. Below are our findings. The block is plenty thick everywhere but right at the deck where the walls become to thin at the 80.5mm bore. Thats why the 1.8L kits were cracking the blocks.
Excuse my ignorance as I just picked up my R53 less than a week ago but if the issue is wall thickness and there is plenty of block left are you not able to overbore and sleeve the block? Is a sleeving solution not available or are there other issues complicating the matter?
Excuse my ignorance as I just picked up my R53 less than a week ago but if the issue is wall thickness and there is plenty of block left are you not able to overbore and sleeve the block? Is a sleeving solution not available or are there other issues complicating the matter?
The cylinders in a R53 block are made too close together, therefore you are not able to overbore and sleeve the block.
The cylinders in a R53 block are made too close together, therefore you are not able to overbore and sleeve the block.
I would imagine that true with a dry liner but with the proximity to the water jacketing a wet sleeve should work. I see Darton produces a wet sleeve for the R56, have they been contacted about production for the R53?
Sorry we forgot to give all of you an update last week. Here are the pistons we are getting made for these kits. The pistons are being custom made for Sneed4Speed by Ross Racing Pistons, they are a forged piston and we are able to get a 8.7 to 1 compression ratio with them.
i assume a built engine will be over 4grand.. rip wallet.
Our big bore kits are available for purchase without getting an engine from Sneed4Speed for $1,098.00 the kit includes big bore pistons, rings, wrist pins and matching MLS head gasket. Kit can be used with any stock length connecting rod.
Our big bore kits are available for purchase without getting an engine from Sneed4Speed for $1,098.00 the kit includes big bore pistons, rings, wrist pins and matching MLS head gasket. Kit can be used with any stock length connecting rod.
Forgive my ignorance but this means, that I could buy your big bore kit, pull my motor, and take the motor with the kit to an engine builder/machine shop and they could bore out my motor and reassemble it? this is rather tempting, any idea/estimate on the power gained by increasing the displacement?
Forgive my ignorance but this means, that I could buy your big bore kit, pull my motor, and take the motor with the kit to an engine builder/machine shop and they could bore out my motor and reassemble it? this is rather tempting, any idea/estimate on the power gained by increasing the displacement?
That's correct Racingguy! Our race engine makes around 250hp with just the big bore kit added to the engine we made power in the 270hp range.
what would be your estimation with a good bvh, mild cam, 17% pulley, header and catback, intake and injectors
280whp? assuming its tuned correctly?
I would say a good estimate would be around the 225 - 250 range, as you stated tuning does have a lot to do with that. Our race engines do come with ported and polished heads, bigger valves, and heavier valve springs, as well as an upgraded cam.
Just wanted to give everyone an update to clarify some questions we have had. Our kit does not require buying a full engine from Sneed4Speed, nor does our kit require any cylinder sleeves. We have cut a test block in half and measured the cylinder walls and have confirmed that it is safe to bore these engines to fit our kits. We also have tested these kits in engines with no problems.
Yes, our kit will fit both blocks. The R50 and R53 blocks are basically the same. The R50 doesnt have piston oil squirters that is the main difference.
But the normally aspirated R50's compression ratio is 10.6:1. Taking that down to 8.7:1 would, uh, well at least you could run regular gas. I must be missing something.
You ask about the R50 block. The R50 rotating assembly is totally different from the R53. The crank is not forged, the rods are longer and the piston pin height is different. To install our 1.7 pistons with R50 rods would cause the pistons to come out of the top of the block.
not to beat the R50 to death to take too much of your time, but I have one... With the lower compression and the larger displacement, knowing that this was not part of your build/thought process, what kind of bhp would you guess this would make in an R50?
If you just slapped a 1.7 big bore kit and R53 crank and rods into a R50 block you would lose power. You could however install the 1.7 pistons with the correct length rod and R50 crank and keep the compression ratio close to where it is stock then power output would be about 8-12% higher than a stock R50 engine. We would have to mock it up here to figure out the rod length needed. It would be longer than the R53 but shorter than R50 rods
