Gudgeon pin - Oil Feed
bikecarbfred - 27/11/15 at 10:53 PM
I'm changing from i-beam to H-beam. Using the VW 1.8T H-beams which you can buy from ebay (£200 for a set)
I know it's been done before on my type of engine but that's all I know.
I wanted to ask how important is the oil feed style to the piston pin.
My I-beam conrods have a oil feed hole that goes right up to the top bearing that pressure feeds oil to the pin.
The H-beams just have one oil feed hole in the top bearing that sits ontop of the PIN.
In this design is enough oil fed in this hole via splish splash?
I also read one a few forum posts on the web that oil feed to the gudeon pin is not that vital.
Nickp - 28/11/15 at 07:01 AM
Little ends don't need a pressure feed but they do need oil to them via the 'splish splash' method you describe.
Does your block have oil squirters? If so then you should be fine.
In my last engine build (Fiat/Lancia TC) the std rods had squirters at their base but I replaced them with H beam rods like you have. To compensate
for the lack of squirters I made 3 groves in the upper shoulder of the big end of the rod so the pressurised oil from there would go up the bore
snapper - 28/11/15 at 08:59 AM
Pinto rods have a spray jet in the rod flank just above the big end that sprays the underside of the piston when I fitted Cosworth rods which
don't have the spray hole there were 2 options, I made it more difficult by using an RS2000 sump so bought an RS2000 pickup and a Cosworth pickup
with spraybar and grafted the 2 together then having the RS2000 sump modified where the spraybar fouled
Then I found the simple solution which is to notch the rod big end at the top near the rod flank which throws enough oil upwards to lubricate the
pin
Nickp - 28/11/15 at 09:38 AM
quote:
Originally posted by snapper
Pinto rods have a spray jet in the rod flank just above the big end that sprays the underside of the piston when I fitted Cosworth rods which
don't have the spray hole there were 2 options, I made it more difficult by using an RS2000 sump so bought an RS2000 pickup and a Cosworth pickup
with spraybar and grafted the 2 together then having the RS2000 sump modified where the spraybar fouled
Then I found the simple solution which is to notch the rod big end at the top near the rod flank which throws enough oil upwards to lubricate the
pin
That's similar to what I did but 3 smaller grooves either side. One pointing straight up at the pin and the other 2 at about 30deg either way
from the first.
bikecarbfred - 28/11/15 at 08:59 PM
quote:
Originally posted by Nickp
Does your block have oil squirters? If so then you should be fine.
In my last engine build (Fiat/Lancia TC) the std rods had squirters at their base but I replaced them with H beam rods like you have. To compensate
for the lack of squirters I made 3 groves in the upper shoulder of the big end of the rod so the pressurised oil from there would go up the bore
No the block has no squirters near the cylinder walls so im guessing it relies on splish splash from conrods dipping in and out of oil sump.
Imagine driving like a grandad for 50,000 miles by keeping revs in 1000-2000rpm.
You might not get as much lubrication up them walls. Hard to say not being able to see what goes on in there.
Also I have seen some H- beams that have two diy drilled oil feeds at the lower sides of the small end. The holes are angled in.
Wonder if they serve better lower down than being on top.
bikecarbfred - 9/12/15 at 09:58 PM
VW 1.8T - Golf , Passat (144mm) Turbo - forged rods ** PRISM ** ( H-Beam type)
Guys, On one of these pictures there is a oil feed in the big end. This can't go to the small end so where do you reckon it does.
Nickp - 9/12/15 at 10:15 PM
quote:
Originally posted by bikecarbfred
VW 1.8T - Golf , Passat (144mm) Turbo - forged rods ** PRISM ** ( H-Beam type)
Guys, On one of these pictures there is a oil feed in the big end. This can't go to the small end so where do you reckon it does.
Probably just a generic picture of rods that do have an oil feed, to a squirter maybe? Another pic shows 6 rods but I presume you're not
expecting them to send you 2 spares?
[Edited on 9/12/15 by Nickp]
bikecarbfred - 9/12/15 at 10:24 PM
lmao - there's a chinese seller on there with multiple listings and even with different ebay names lol.
Everytime I ask a question it's the same person emailing me. anyone I'm going for a h-beam set from there with upgraded l19 bolts as
don't trust the standard bolts from China.
144cm centre to centre
50.60 big end
24.9 big end width (needs to be 20)
24.9 small end width (needs to be 20)
20 mm pin diameter (needs to be 17)
I then have to have get machined off 2.5mm of each side of the big end and small end.
Then remove the brass insert which I believe should be easy if thier all pressed in the same.
And insert a 17mm bushing.
So cost wise it will be:
£200 rods
£100 machining
£50 have bushing removed and new fitted
total 350 and will only be running 150-160bhp
MikeRJ - 16/12/15 at 12:07 PM
quote:
Originally posted by bikecarbfred
No the block has no squirters near the cylinder walls so im guessing it relies on splish splash from conrods dipping in and out of oil sump.
It's called splash lubrication, no need to add the splish 
The big ends DO NOT dip into the oil in the sump, unless you have grossly over filled the engine with oil. If this happened the power losses would be
huge, and the oil would get whipped up into a froth.
Do you really need the expense of H beam rods if you are only running 160bhp?
[Edited on 16/12/15 by MikeRJ]
snapper - 16/12/15 at 12:24 PM
It's the revs that kill rods not the horses
bikecarbfred - 16/12/15 at 03:13 PM
@ Mike: yes because you won't believe how skinny the standard rods are on the AFH.
I could have bought slightly thicker I-beams and had the bushing done to them but that increases the weight.
So I managed to get a set of h-beams for £189 that only weigh 40 grams per rod more and are the correct widths it terms of small and big.
All it needs is the 19mm bush pressing out and a 17mm one pressing in.
