GT40, about to make the leap!!

[ChrisP]

Although I haven't uploaded many pics I have been busy!!!

I popped out the pistons of the 302 (196



Big ends are pretty good. The pistons and rings look pretty good too, although one was showing some signs of a bit of heat. They are plus 30 thou, so more options available on the block. Rods look good although I have not yet checked them for round. So onwards and the crank.......



which also looks pretty good. Some slight signs of wear. Bearings all good but will replace anyway. It's plus 20 thou so plenty of scope. Whether it's straight or not remains to be seen!

Then the bores ......



There are some scratches on a few of the bores in the lower section (below the rings). They are not bad and may hone out. Not sure what could have caused it as the bores have hardly had any wear since rebore. In fact, they have only just shone up and you can still see the newness where the skirts don't go. Could have been assembled with dirty fingers/workshop maybe?? I mentioned early in this thread that this motor had four bent pushrods and a bent valve (No 7 cylinder). No damage to the piston at all, not even a mark. Weird.
I also pulled the cam. Whether the cam was a bit wild and either the cam timing was a bit off or the piston/valve clearances were too tight, who knows. I can't ID the cam so will probably just bin it and put something in with known data I can work with.
The inlet manifold was a Weiand single plenum racing type (30 years old) that would suit a high revving engine, so could be the whole set up was on the wild side. Who knows.

I am taking the block et al to the machine shop tomorrow for some checks to see where we go. I was hoping to re-ring/shell and use the pistons and crank without spending out more but we will see!
If I need new pistons then maybe a 347 is on the cards after all!!!

[ChrisP]

Oh, and I have just about stripped the whole car now. I must nearly be getting to the point where the mess will come to a stop and it will start looking like I an getting somewhere!! I now have a scruffy looking chassis on the lift and a workshop full of what is mostly crap! Plus a trailer outside full of very sharp stainless sheet!
Even with the sun shining it doesn't look any better!!! Keep calm and carry on I guess..........

[Darnpistonbroke]

Regarding your engine with bent push rods. Do you have hydraulic lifters? Just wondering if someone previously had gone into these without knowing what they are doing and reassembled them incorrectly. If that has happened then they could fill with oil but without the control thus hydraulic locking whilst full of oil. This will cause the designed gap to close too soon giving your pushrod nowhere to go, thus bending them.
I have had little experience with automotive hydraulic lifters as the ones I am used to are aircraft piston engine ones which can be dismantled and cleaned. Don't know if you can do that with automotive ones.

Also, word of advice. Despite what has been seen on TV is car SOS, Wheeler Dealers, etc, NEVER remove hydraulic tappets or valve spring retaining collets with a magnet. Very poor practice which can magnetise the items. If a hydraulic tappet becomes magnetised it can hold the little ball bearing off its seat causing the designed hydraulic lock to not occur and render the tappet useless. This will result in the cam shaft beating hell out of the cam follower and destroying the cam lobe.
Magnetised collets will attract iron filings and cause wear, where you don't want it which is possibly in the valve guides.

As you have probably guessed I'm pretty hot on magnets and engines, I avoid mixing the two like I try to avoid COVID!

Just a thought.

David.

[aaronjb]

Great progress Chris! Spring meet at your place once we've all had our Pfizer tracking chips implan.. I mean, vaccines?

David - collets I can figure out; pick them off the valve stem on a screwdriver with a blob of grease* (same way they go in) but how do you get lifters out of their bores without a magnet? Hm.. sucker on a stick, maybe?
(*Or in my case, fish them out of the head of the fiancee's MINI after they've fallen off before I could catch them, luckily none of them disappeared into the sump!)

[Darnpistonbroke]

Great progress Chris! Spring meet at your place once we've all had our Pfizer tracking chips implan.. I mean, vaccines?

David - collets I can figure out; pick them off the valve stem on a screwdriver with a blob of grease* (same way they go in) but how do you get lifters out of their bores without a magnet? Hm.. sucker on a stick, maybe?
(*Or in my case, fish them out of the head of the fiancee's MINI after they've fallen off before I could catch them, luckily none of them disappeared into the sump!)

In the bowl of the lifters where the pushrod sits, is there a small drilling to allow oil to escape? Certainly with Lycoming and Continental aircraft engines there are. I poke a small piece of wire into this with a right angled bend right at the end and hook them out.
If there isn't then I would suggest using something like the stick you lap valves in with. The stick with a couple of suckers on, one large one and one small one. That should create enough suction to grab the tappet and gently drag it out. It should work if there is no drilling in the dip. Or a blob of very thick and sticky grease. Fuel lube is good for this. Its a very thick, sticky grease used to lubricate fuel components where there is a risk of the fuel washing ordinary grease out.

David.

[ChrisP]

OK, been to have a chat with an engine building mate and then down to the machine shop. There is good news and bad news!!!!

7 of the 8 bores would clean up without a re-bore but darn it, that one bore means I need to go another 10 thou and am in to a set of pistons. So just looking at that, will probably go for some Keith Black 116 jobbies with the solid bump on them that will allow me to go for the bigger valved head with 2.02 inlet valves - the standard pistons (although a bit cheaper, will not work with the 2.02 and need a 1.90 valve). I should be able to get 10.5 to 1 compression with that set up.

We managed to identify the cam. Turns out it's what is now called an Edelbrock Performer! Just what I wanted. Except, darn it again, the previous builder had the end float all wrong (I think incompatible timing cog/cam/plate) allowing the cam to move about badly which has chipped some of the edges and messed the drive. That probably explains my bent valve (chip plus lift equalled contact)

So it looks like an Edelbrock top end kit after all. Big valve Performer RPM heads, Performer cam, Performer RPM Manifold which I hope with the KB pistons will get me near 367hp

New lifters and pushrods obviously. Also probably Eagle rods with 3/8 rod bolts as I understand the standard ones 5/16) at 360hp might be a bit vulnerable. Any comments?????

The crank looks good and hopefully will polish up. Fingers crossed on that one. And the block itself looked OK. I left that there for checking. Oh, and I need a new harmonic balancer! This is all getting a bit pricey.

Any guidance gratefully received. I have never built a small block before so I am guessing/reading/listening!!

[String]

Chris

Interesting build thread, enjoying following it.

Whilst you’ve got the lump in pieces, and if you have a die grinder and it hasn’t already being done, you could consider flowing the oil drain back holes and cleaning up any flashing on the block etc. Unlikely to enhance performance by much, but whilst you’re being thorough, why not...running a tap through all bolt holes (or the correct threaded bolt with a shallow channel cut along its length) will help clean those up too.

I’m far from expert, mine being a SBC besides, but the above tips were gleaned from reading many books and talking with a couple of local engine builders who are experts. HTH and keep up the good work. Cheers.

[aaronjb]

This is all getting a bit pricey.

Next thing you know you'll be £10k in and drammyboy will be telling you that you could have had a perfectly adequate RV8 for £300

Plan sounds good though - albeit expensive. The cheapest way I found to get the parts here was Jegs/Summit to a freight forwarder and then wait the six weeks or so for the slow boat.. but that was the FE, maybe the smallblocks are more readily supported this side of the pond by the likes of Real Steel et al?

[ChrisP]

You are not wrong Aaron. Not so bad though, a set of decent pistons is £258. It all adds up that’s the problem! I need the pistons to get the machining done otherwise I am in to a big delay. Then I need the front balancer and flywheel to get the bloody thing balanced........... Not that there is a rush, just that now I am in to it I want to get on.
Very definitely yes to a meet up here with the cars when weather and COVID has improved. Plenty of space for the cars. Would be fun. Could also do a run to Classic Car Hub or Caffeine and Machine very easily from here. It will be a while before the GT40 turns a wheel though (even if it had any!!)

[Lloyd Barnes]

Worth checking the valve springs, v the cam lift x rocker ratio If you have bent push rods but no piston damage it could be the valve springs binding. Too much lift for the available valve travel etc.