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Peppy's Build Thread


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  • Member
  • Member For: 21y 7m 30d
  • Gender: Male

I think the oil feed to the little end is quite important for very high powered vehicles. I remember someone (I think Nizpro) show pictures of gaulling of the pin and piston under very heavy load. That was years ago, I also remember the pins years ago were not that strong and bending, so the pins of today maybe wont be so much of a problem.

Nevertheless I would rather use a pin with an oiling hole to the small end any day. The H Beam Argos I used in my last rebuild couldnt accomodate a hole to the small end so maybe need another design of rod as have already been mentioned.

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  • REST IN PEACE V8
  • Donating Members
  • Member For: 16y 7m 8d
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  • Location: Woodridge on the park bench

Yeah I believe the main cause was clearances weren't correct as they were under a thou on the bearings now its setup with just under two thou. So the motor isnt as tight plus theres no fuel mixing with the oil.Just get the rods rifled drilled and should be sweet. we also had some issues with the atomic oil pump and oil pressure which we contributed to the rods being rifle drilled. But ended up being the atomic oil pump needing the spring and valve adjusted to accommodate the ported housing. Your running just the spool gears so should be all good

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  • Member For: 11y 7m 26d
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  • Location: Liverpool

Hey Guys, thanks for the info, it has been taken on board and I've asked the questions to both my dad and the machinist and we came to the conclusion that I will not be rifle drilling the rods, if I really want the oil feed to the small end I am better off getting new rods with them already done, so I will keep going with these this time around...

As for the line boring, they both also thought it was un-necessary for this motor... They said if the crank doesn't turn nicely once torqued up then do it otherwise it's not necessary..

Anyway, I haven't got around to finishing flow testing the head, but I got the block and crank back, first up I gave everything a good glean, stoned all the flat surfaces, scrubbed and blew all the holes...

Wd40 went over everything after its wash and ready to be dummy assembled to work out what Comp I want... So I put all the bearings in, crank in then caps and studs, the spool girdle doesn't have any identification of front or back, and can go on either way as long as the countersunk holes go over the caps... I started torquing it up, obviously spinning the crank while torquing, once I got to #2 cap it clamped the crank, firstly I freaked out thinking that I should of got it line bored, so took the girdle off and started torquing the caps down without the girdle, luckily once done the crank spun freely, I put the girdle back on the same way and just watched the #2 cap while torquing it, the countersunk hole was touching the cap and pulling it sideways clamping the crank.. Took it all apart again had a good look at the cap checking all the flat surfaces etc and all looked good, it was obviously the girdle as it was fine when I just torqued down the caps, so tried the girdle on the other way, torqued it all up and it was fine! Spins like a gem.. So for future reference the spool girdle goes with the "SPOOL" stamp to the back.. I measured the thrust movement and come up with 0.005" which I'm happy with.

Next I put a piston and rod in #1 cylinder to measure the deck height, it came up as 0.038" below deck, I took that out and used it in cylinder #3 and again in #6 coming up with the same 0.038" on all of them.. So that's a good start..

The Pistons are supposed to have a 14cc dish and everything I've read say that the chamber is 65cc, but obviously I'm going to measure it myself, the Pistons came up at 14cc but the chamber was 66cc with the standard valves in... That's as far as I got, so I'll have to sit down and do some calculations for the comp, I'm still unsure of what head gasket I'm using so that obviously plays a part aswell.. Some quick calcs show that the most I would be able to achieve with the 14cc Pistons is about 9.5:1, it not a whole lot but should still be low enough to take 25+psi on 98 happily...

Thanks, Joe

I was abit slack with the photos, I'll take more the next time I'm in the garage

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  • Member For: 11y 7m 26d
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  • Location: Liverpool

Thanks guys, yea I'm aware of that captain, those figures are just to get an idea of where it is currently and to work out where it could be, I will be modifying the chamber slightly, as I believe we can pick up sum flow in a couple spots, so I'll definitely measure them all after that

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  • Member For: 11y 5m
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How are you approaching the porting?

is it a case of grind then measure flow until flow does not improve?

Have you seen the shape or flow figures for any heads that you know work well to have something to aim for?

I don't think porting is very common on these engines, so I am interested in how this goes for you.

I suspect you will get some nice results from it.

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  • Member For: 11y 7m 26d
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I must admit that dad will be overlooking the porting very closely if not he will do the important parts and I'll just clean it up... He has ported a few of these but one was for an NA speedway car way back when he had his shop, luckily he is thorough enough to have noted all the changes and progress flow tests so we have a really good base to start from, I'm still utilising the standard fg intake manifold so that will also be a limiting factor in that we will only push the head to flow whatever the manifold can, so basic match porting to the gaskets and from my understanding there will be abit to be picked up from opening up the bowl a little, we will be punching the guides down to get a clean run at slimming down the guide boss, then on the exhaust side dads thinking we should take abit of meat off the top side kind of like hi-porting it 2-3mm to promote flow out the exhaust... Then the seat cutting angles play a big part as well, I'll try and document as much as I can and take photos to help people out

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  • Member For: 11y 7m 26d
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In saying that, I'm happy to share my findings but we'll try and keep the information to this thread and the people that read it, I'm not gonna go and start a "How to Port" thread or anything...

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  • less WHY; more WOT
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  • Member For: 16y 7m 19d
  • Gender: Male
  • Location: Melbourne

No stress, mate. Any pics/information you're willing to share is great! We don't expect a full how to :) But if you want to go into such details, I'm sure nobody would object :)

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